BTH-1208LS-OEM
Wireless Multifunction DAQ Device

User's Guide

July 2019. Rev 7© Measurement Computing Corporation

Trademark and Copyright Information
Measurement Computing Corporation, InstaCal, Universal Library, and the Measurement Computing logo areeither trademarks or registered trademarks of Measurement Computing Corporation. Refer to the Copyrights &Trademarks section on mccdaq.com/legal for more information about Measurement Computing trademarks.
Other product and company names mentioned herein are trademarks or trade names of their respective
companies.
© 2019 Measurement Computing Corporation. All rights reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted, in any form by any means, electronic, mechanical, by
photocopying, recording, or otherwise without the prior written permission of Measurement Computing
Corporation.
NoticeMeasurement Computing Corporation does not authorize any Measurement Computing Corporation product for
use in life support systems and/or devices without prior written consent from Measurement Computing
Corporation. Life support devices/systems are devices or systems that, a) are intended for surgical implantation
into the body, or b) support or sustain life and whose failure to perform can be reasonably expected to result ininjury. Measurement Computing Corporation products are not designed with the components required, and are
not subject to the testing required to ensure a level of reliability suitable for the treatment and diagnosis ofpeople.

HM BTH-1208LS-OEM.docx

Table of Contents
Preface

About this User's Guide ....................................................................................................................... 5
What you will learn from this user's guide ......................................................................................................... 5
Conventions in this user's guide ......................................................................................................................... 5
Where to find more information ......................................................................................................................... 5
Chapter 1

Introducing the BTH-1208LS-OEM ...................................................................................................... 6
Functional block diagram ................................................................................................................................... 7
Chapter 2

Installing a BTH-1208LS-OEM .............................................................................................................. 8
Unpacking........................................................................................................................................................... 8
Downloading the software .................................................................................................................................. 8
Pairing with the host device ................................................................................................................................ 8
Installing the hardware in USB mode (Windows only) ...................................................................................... 9
Configuring Bluetooth settings ........................................................................................................................... 9
Calibrating the hardware..................................................................................................................................... 9
Chapter 3

Functional Details ............................................................................................................................... 10
Analog input acquisition modes ....................................................................................................................... 10
Software paced mode .......................................................................................................................................................10
Hardware paced mode......................................................................................................................................................10
BURSTIO ........................................................................................................................................................................11

Board components ............................................................................................................................................ 11
USB connector .................................................................................................................................................................11
Power/pairing button........................................................................................................................................................12LEDs ................................................................................................................................................................................12
Connector J1 ....................................................................................................................................................................13
Connector J2 ....................................................................................................................................................................13
Connector J3 ....................................................................................................................................................................13Signal connections ............................................................................................................................................ 14
Analog input ....................................................................................................................................................................14
Analog output ..................................................................................................................................................................15
External clock input .........................................................................................................................................................15
Digital I/O ........................................................................................................................................................................15
External pull-up/pull-down capability .............................................................................................................................15
Bulkhead signals ..............................................................................................................................................................16
Trigger input ....................................................................................................................................................................16
Counter input ...................................................................................................................................................................16
Ground .............................................................................................................................................................................17
Power output ....................................................................................................................................................................17

Mechanical drawing ......................................................................................................................................... 17
Chapter 4

Specifications ...................................................................................................................................... 18
Analog input ..................................................................................................................................................... 18
Accuracy ..........................................................................................................................................................................19
Noise performance ...........................................................................................................................................................19

Analog output ................................................................................................................................................... 20
Digital input/output........................................................................................................................................... 21
External trigger ................................................................................................................................................. 22External clock input .......................................................................................................................................... 22
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BTH-1208LS-OEM User's Guide

Counter ............................................................................................................................................................. 23
Memory ............................................................................................................................................................ 23
Microcontroller ................................................................................................................................................. 23
Power ................................................................................................................................................................ 24
Bluetooth .......................................................................................................................................................... 24
USB .................................................................................................................................................................. 24
Environmental .................................................................................................................................................. 24
Mechanical ....................................................................................................................................................... 25
Signal connectors .............................................................................................................................................. 25
Analog signals (J1) ..........................................................................................................................................................25
Digital signals (J2) ...........................................................................................................................................................25
Bulkhead signals (J3) .......................................................................................................................................................26

4

Preface

About this User's Guide
What you will learn from this user's guideThis user's guide describes the Measurement Computing BTH-1208LS-OEM wireless data acquisition device
and lists device specifications.

Conventions in this user's guide
For more information
Text presented in a box signifies additional information and helpful hints related to the subject matter you arereading.
Caution! Shaded caution statements present information to help you avoid injuring yourself and others,
damaging your hardware, or losing your data.
Bold text is used for the names of objects on a screen, such as buttons, text boxes, and checkboxes.

Italic text is used for the names of manuals and help topic titles, and to emphasize a word or phrase.

Where to find more information
Additional information about the BTH-1208LS-OEM is available on our website at www.mccdaq.com. You canalso contact Measurement Computing Corporation with specific questions.
§§§§

Knowledgebase: kb.mccdaq.com
Tech support form: www.mccdaq.com/support/support_form.aspx
Email: techsupport@mccdaq.com
Phone: 508-946-5100 and follow the instructions for reaching Tech Support

For international customers, contact your local distributor. Refer to the International Distributors section on our
website at www.mccdaq.com/International.

5Chapter 1

Introducing the BTH-1208LS-OEM
The BTH-1208LS-OEM is a multifunction data acquisition device that communicates using Bluetooth®
wireless technology.
The Bluetooth radio host used with the device must support Bluetooth 2.0 or later. The following Bluetooth
stack protocols are supported on Windows:§§

Microsoft Bluetooth stack
Broadcom ® Bluetooth stack (not supported by Windows XP)

The device supports USB 2.0 full-speed when connected to a USB port. The device is also compatible withUSB 1.1 ports; however, the speed of the device may be limited when using a USB 1.1 port due to thedifference in transfer rates on USB 1.1 versions of the protocol (low-speed and full-speed).
The BTH-1208LS-OEM provides the following features:
§
§
§
§
§
§
§
§
§
§
§

Eight 11-bit single-ended (SE) or four 12-bit differential (DIFF) analog input channels
1 kS/s max sample rate in Bluetooth continuous scan mode
47 kS/s sample rate in Bluetooth BURSTIO mode and when communicating over USB connection
Software-selectable analog input ranges of ±10 V (SE), and ±20 V, ±10 V, ±5 V, ±4 V, ±2.5 V, ±2.0 V,±1.25 V, and ±1.0 V (DIFF).
Two 12-bit analog outputs
Eight individually-configurable digital I/O channels
One 32-bit event counter
One external digital trigger input
One external clock input
Three header connectors for field wiring
Header connectors available for user-supplied power; can also be powered by a USB power supply inBluetooth mode or from the USB host device in USB mode. Connectors for battery power and battery
charging are also included.

Caution! There are no product safety, electromagnetic compatibility (EMC), or CE marking complianceclaims made for the BTH-1208LS-OEM. The BTH-1208LS-OEM is intended for use as acomponent of a larger system. MCC can help developers meet their compliance requirements. The
end product supplier, however, is responsible for conforming to any and all compliancerequirements.

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BTH-1208LS-OEM User's Guide

Introducing the BTH-1208LS-OEM

Functional block diagram
BTH-1208LS-OEM functions are illustrated in the block diagram shown here.

Figure 1. Functional block diagram

7

Chapter 2

Installing a BTH-1208LS-OEM
UnpackingAs with any electronic device, you should take care while handling to avoid damage from static
electricity. Before removing the board from its packaging, ground yourself using a wrist strap or by simply
touching the computer chassis or other grounded object to eliminate any stored static charge.

Downloading the software
Refer to the BTH-1208LS-OEM product page on our website for information about the supported software you
can download.
Install the software before you install the hardware
The driver needed to run the device is installed when you install the software. Therefore, you need to install thesoftware package you plan to use before you install the hardware.

Pairing with the host device
Pairing creates a bond between a Bluetooth device and a host device. A host device can be either a Windowsbased computer or an Android device (tablet, phone, or mini-PC).
The BTH-1208LS-OEM must be paired with the host device before it can establish a wireless connection andtransmit acquired data to the device. A BTH-1208LS-OEM only has to be paired once with a particular hostdevice.
The BTH-1208LS-OEM can be paired or connected when powered by:§§batteries (standard or rechargeable)
an external USB power supply

The BTH-1208LS-OEM cannot be paired when powered by a USB host device.
To pair the BTH-1208LS-OEM as a Bluetooth device, make sure the device is not connected to a USB host, andcomplete the following steps (refer to Figure 2 on page 11 for the location of device components referenced inthis section):
1.

Make sure the host device is configured to host a Bluetooth device. Refer to host device documentation tolearn how to enable Bluetooth and how to search for and pair with Bluetooth devices.

2.

If powered by batteries, press and hold the button for at least five seconds to power on the device and put it
into pairing mode.
If powered by a USB power supply, press and hold the button for at least three seconds to put the device
into pairing mode.
When the Power and Status LEDs blink alternately, the device is in pairing mode and is ready to pair withthe host device.

3.

Select the Bluetooth device setup in the host device OS software, and then select the BTH-1208LS-OEM
when it displays. Refer to the Bluetooth documentation of your host device to learn how to pair it with aBluetooth device.
For example, in Windows, select Bluetooth Device from the Control Panel, and then double-click on
BTH-1208LS-OEM-xxxx in the Add a device dialog box (xxxx are the last four digits of the device serial
number. You may need to wait a few seconds for the device to display.

4.

If host device requests a passkey, PIN or pairing code, enter the default value for the device (0000).

5.

Press and hold the power/pairing button for two seconds to remove the device from pairing mode.

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BTH-1208LS-OEM User's Guide

Installing a BTH-1208LS-OEM

Once the BTH-1208LS-OEM is paired to the host device, run an application that communicates with the device(such as InstaCal or a UL for Android example program) to establish a connection. The Status LED turns on toindicate a Bluetooth connection is established.
Digital ground to earth ground connection recommended
Measurement Computing recommends that you connect one of the digital grounds (GND) to earth ground to
reduce the chance of the BTH-1208LS-OEM unexpectedly powering down due to electrostatic discharge.

Installing the hardware in USB mode (Windows only)
The driver needed to run the BTH-1208LS-OEM device is installed when you install the software. Therefore,
you need to install the software package you plan to use before you install the hardware. For operation on a
Windows operating system, Measurement Computing recommends that you run Windows Update to update
your operating system with the latest USB drivers.
Connect the USB cable to an available USB port on the computer or to an external USB hub connected to thecomputer. Connect the other end of the USB cable to the USB connector on the device. No external power isrequired.

Configuring Bluetooth settings
All Bluetooth settings except for the pairing code can be changed when the BTH-1208LS-OEM is either
physically or wirelessly connected to the host device. The pairing code can only be changed when the
BTH-1208LS-OEM is physically connected to the host device.
You can configure the following Bluetooth settings on the BTH-1208LS-OEM through software. For example,
if you are using the device in a Windows environment, you can configure these settings with InstaCal.
§§§§

Pairing code – Four digit code that identifies the BTH-1208LS-OEM to the host device (default = 0000).

The pairing code cannot be changed when the BTH-1208LS-OEM is connected wirelessly to the hostdevice.
Bluetooth connection status notifications – You can set values that indicate when the device isconnected over Bluetooth, and when the Bluetooth connection terminates. Connected and disconnectedvalues can be set for digital outputs, analog output channel 0, and analog input channel 1
Auto shutdown – When the device is powered by batteries, you can configure the device to power down a
specified amount of time after the Bluetooth connection terminates.
Battery charging – When the device is powered by rechargeable batteries, you can configure the device torecharge batteries from the USB power supply when connected over Bluetooth.

Calibrating the hardware
The Measurement Computing Manufacturing Test department performs the initial factory calibration. Returnthe device to Measurement Computing Corporation when calibration is required. The recommended calibrationinterval is one year.

9Chapter 3

Functional Details
Analog input acquisition modes
The BTH-1208LS-OEM can acquire analog input data in three different modes – software paced, hardware
paced, and BURSTIO.

Software paced mode
In software paced mode you can acquire one analog sample at a time. You initiate the A/D conversion bycalling a software command. The analog value is converted to digital and returned to the computer. You repeat
this procedure until you have the total number of samples that you want from one channel.
§§

When communicating over a Bluetooth connection, the typical throughput sample rate in software pacedmode is 10 S/s (system-dependent).
When communicating over a USB connection, the typical throughput sample rate in software paced modeis 250 S/s (system-dependent).

Hardware paced mode
In hardware paced mode you can acquire data from up to eight channels. The analog data is acquired andconverted to digital values until you stop the scan.
§

When communicating over a Bluetooth connection, the maximum sample rate of 1024 S/s is an aggregate
rate. The total acquisition rate for all channels cannot exceed 1024 S/s. The following table lists the sample
rates when scanning from one to eight channels in Bluetooth mode.
Maximum per channel sample rate in Bluetooth mode§

# channels scanned

Sample rate (S/s)

1
2
3
4
5
6
7
8

1024
512
341.33256204.8
170.67146.28128

When communicating over a USB connection, the maximum sample rate of 47 kS/s is an aggregate rate.
The total acquisition rate for all channels cannot exceed 47 kS/s. Data is transferred in blocks of 32 samples
from the device to the memory buffer on your computer.
The following table lists the sample rates when scanning from one to eight channels in USB mode.
Maximum per channel sample rate in USB mode
# channels scanned

Sample rate (kS/s)

1
2
3
4
5
6
7
8

47
23.5
15.67
11.75
9.40
7.83
6.70
5.88

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Functional Details

In both Bluetooth mode and USB mode, you can start a hardware-paced scan with either a software commandor with an external hardware trigger event.

BURSTIO
When using BURSTIO, the BTH-1208LS-OEM can acquire data at the maximum throughput of 47kS/s whenconnected in Bluetooth mode. BURSTIO doesn’t offer any advantage in USB mode, since these rates aresupported for BLOCKIO in USB mode.
When BURSTIO is enabled, scans are limited to the depth of the onboard memory (12,288 samples), as the datais acquired at a rate faster than it can be transferred to the computer. Keep in mind that when using Bluetooth
the rate of transfer of the acquired data to the host is still limited so the process can take several seconds. Time
must be allowed between scans for the acquisition and the transfer of the data.
The maximum sample rate is an aggregate rate. The total sample rate using BURSTIO is 47 kS/s per channel forany or all channels. An error occurs if you exceed the FIFO capacity and acquire more than 12,288 samples in
BURSTIO mode.

Board components
The BTH-1208LS-OEM has the following components, as shown in Figure 2.

1
2
3Connector J2
Connector J3
Connector J1

45
6

USB connector
Power/Pairing Button
Power LED (top) and Status LED (bottom)

Figure 2. Board components

USB connector
The USB connector provides 5 V power when connected to a USB power supply, and provides both power andcommunication when the device is connected to a USB port. If rechargeable batteries are powering the device,recharges batteries when connected to USB host or power supply.
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Functional Details

Power/pairing button
The power/pairing button has different functions depending on the power source of the device.
The term pairing refers to one function of the button – to put the device in pairing mode so it can establish an
association between the Bluetooth radio on the host device and the BTH-1208LS-OEM radio.
Button functions are listed in the table below.
Power/pairing button functions
Power Status

Button Functions

Battery powerednPowered by USB
charger/USB power
supplyPowered by USB hostport or hub

To power on the device, press and hold the button for 3 seconds. To enter pairing mode,
hold the button for an additional 2 seconds.
n To remove the device from pairing mode, press and hold the button again for 2 seconds.
n To power off the device when not in pairing mode, press and hold the button for 2 secondsn To put the device in pairing mode when it is powered on, press and hold button for 2
seconds.
n To remove the device from pairing mode, press and hold the button again for 2 seconds.
The power/pairing button is disabled.

LEDs
The Power LED indicates the power status of the device. The Status LED indicates the communication status of
the device.
LEDs cannot be disabled. LED states are listed in the tables below.
Power and Status LED behavior
Power LED

Indication

Steady green
Blinks continuously

Off

The device is powered by USB and the batteries are sufficiently charged or not installed.
n Connected to USB port/host: the batteries are recharging (only if rechargeable batteries are
installed).
n The device is not connected to a USB port: indicates battery powern The Power LED blinks alternately with the Status LED: the device is in pairing mode.
Device is off.

Status LED

Indication

Steady green
Blinks continuously

Bluetooth or USB connection establishedn Communication with host computer over a Bluetooth or USB connection.
n The Status LED blinks alternately with the Power LED: the device is in pairing mode.
A Bluetooth or USB connection is not established

Off

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Functional Details

Connector J1
Header connector J1 provides connections for the analog inputs, analog outputs, and analog ground reference.
Refer to Figure 5 on page 17 for the location and orientation of J1.
Four-channel differential mode
Pin
1
3
5
7
9
11
13
15

Signal name
CH0H
CH0L
CH1H
CH1L
CH2H
CH2L
CH3H
CH3L

Pin description
Analog input 0 HI
Analog input 0 LO
Analog input 1 HI
Analog input 1 LO
Analog input 2 HI
Analog input 2 LO
Analog input 3 HI
Analog input 3 LO

Pin
2
4
6
8
10
12
14
16

Signal name
AGND
AGND
AGND
AGND
AGND
AGND
AOUT0
AOUT1

Pin description
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog output 0
Analog output 1

Pin
2
4
6
8
10
12
14
16

Signal name
AGND
AGND
AGND
AGND
AGND
AGND
AOUT0
AOUT1

Pin description
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog output 0
Analog output 1

Eight-channel single-ended mode
Pin
1
3
5
7
9
11
13
15

Signal name
CH0 IN
CH1 INCH2 IN
CH3 IN
CH4 IN
CH5 IN
CH6 IN
CH7 IN

Pin description
Analog input 0
Analog input 1
Analog input 2
Analog input 3
Analog input 4
Analog input 5
Analog input 6
Analog input 7

Connector J2
Header connector J2 provides connections for the DIO, external clock input, trigger, counter, power output, anddigital ground reference. Refer to Figure 5 on page 17 for the location and orientation of J2.
Pin
1
3
5
7
9
11
13
15

Signal name
DIO0
DIO1
DIO2
DIO3
DIO4
DIO5
DIO6
DIO7

Pin description
Digital input/output 0
Digital input/output 1
Digital input/output 2
Digital input/output 3
Digital input/output 4
Digital input/output 5
Digital input/output 6
Digital input/output 7

Pin
2
4
6
8
10
12
14
16

Signal name
GND
CTR
TRIG_IN
AICKI
GND
+VO
GND
GND

Pin description
Digital ground
Counter input
Digital trigger input
Pacer input
Digital ground
3.3V output
Digital ground
Digital ground

Connector J3
Header connector J3 provides connections for bulkhead signals. Refer to Figure 5 on page 17 for the locationand orientation of J3.
Pin
1

Signal name
BATT+

3
5

BATT_MID
THERMISTOR+

79PWR SW+PAIRING SW+

11
13
15

LED1+
LED2+
Vbus

Pin description
Battery input positive(2 AA/AAA cells)
Battery center tap
10 kΩ thermistor positive(battery temperature sensing)
SPST contact 1 (power switch)
Momentary contact 1 (pairing /soft power switch)
LED1 anodeLED2 anodeUSB 5V supply (charging LED
anode)

13

Pin
2

Signal nameBATT–

Pin description
Battery input negative

4
6

GND
THERMISTOR–

Ground10 kΩ thermistor negative

8
10

PWR SW –PAIRING SW–

SPST contact 2
Momentary contact 2

12
14
16

LED1 –
LED2 –CHARGE LED –LED1 cathodeLED2 cathode
Charging LED cathodeBTH-1208LS-OEM User's Guide

Functional Details

Signal connections
Analog input
You can connect up to eight single-ended analog input connections (CH0 to CH7) or four differential
connections (CH0H/CH0L to CH3H/CH3L) on connector J1.
Single-ended configuration
When configured for single-ended input mode, eight analog input channels are available. Each analog input has
11-bit resolution (due to restrictions imposed by the A/D converter) and offers a ±10 V analog input range.
The input signal is referenced to signal ground (AGND), and is delivered through two wires:§ Connect the wire carrying the signal to be measured to CHx.
§ Connect the second wire to AGND.
Single-ended measurements using differential channels
To perform a single-ended measurement using differential channels, connect the signal to the CHxH input, andground the associated CHxL input.
Differential configuration
When the analog input channels are configured for differential input mode, four analog input channels areavailable. A low-noise precision programmable gain amplifier (PGA) is available on differential channels. Eachanalog input has 12-bit resolution and offers software-selectable analog input ranges of ±20 V, ±10 V, ±5 V, ±4
V, ±2.5 V, ±2.0 V, ±1.25 V, and ±1.0 V.
In differential mode, the input signal is measured with respect to the low input. The input signal is delivered
through three wires:§§§

Connect the wire carrying the signal to be measured to CHxH.
Connect the wire carrying the reference signal to CHxL.
Connect the third wire to AGND.

In differential mode, the following two requirements must be met for linear operation:§§

Any analog input must remain in the −10 V to 20 V range with respect to ground at all times.
The maximum differential voltage on any analog input pair must remain within the selected voltage range.

Channel gain queue
The channel gain queue feature allows you to set up a scan sequence with a unique per-channel gain setting andchannel sequence. The gain settings are stored in a channel-gain queue list that is written to local memory on
the device.
The channel-gain queue list can contain up to up to 8 elements in single-ended mode or four elements indifferential mode. The elements must be unique and listed in ascending order. An example of a three-element
list is shown in the table below.
Sample channel gain queue list
Element

Channel

Range

0
1
2

CH0
CH2
CH3

BIP10V
BIP5V
BIP10V

When a scan begins with the gain queue enabled, the BTH-1208LS-OEM reads the first element, sets theappropriate channel number and range, and then acquires a sample. The properties of the next element are thenretrieved, and another sample is acquired. This sequence continues until all elements in the gain queue havebeen selected. When the end of the channel list is detected, the sequence returns to the first element in the list.
This sequence repeats until the specified number of samples is acquired.

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BTH-1208LS-OEM User's Guide

Functional Details

Carefully match the gain to the expected voltage range on the associated channel or an over range condition
may occur. Although this condition does not damage the device, it does produce a useless full-scale reading,and can introduce a long recovery time due to saturation of the input channel.

Analog output
Two 12-bit analog outputs are available at AOUT0 and AOUT1 on connector J1.
Each analog output channel has an output range of 0 V to 2.5 V. Throughput is system-dependent.
The D/A is software paced.

External clock input
The BTH-1208LS-OEM provides one external clock input for the analog input pacer. You can connect anexternal clock signal to AICKI on connector J2.

Digital I/O
You can connect up to eight digital I/O lines to DIO0 through DIO7. The digital I/O terminals can detect thestate of any TTL-level input.
Digital input voltage ranges of up to 0 to 5.5 V are permitted, with thresholds of 0.8 V (low) and 2.0 V (high).
Each DIO channel is an open-drain, which can sink up to 50 mA for direct drive applications when used as an
output.
Figure 3 shows an example of a typical DIO connection. The figure represents connections for one channel. The
other seven channels are connected in the same manner.

Figure 3. Digital output connection example

External pull-up/pull-down capability
Inputs are pulled high by default to 3.3 V through 47.5 kΩ resistors on the circuit board. The pull-up voltage iscommon to all 47.5 kΩ resistors.
You can place an external pull-up resistor on any of the DIO bits in order to limit source current to less than 50
mA, which requires a 100 Ω resistor minimum. A 2 kΩ or 5 kΩ resistor would be typically used, allowing for a
1 mA current
You can also use an external pull-up resistor to pull the DIO bit up to a voltage that exceeds the internal 3.3 V
pull-up voltage (5.5 V maximum).
When using external pull-up resistors, be aware that the internal resistors cause a slight voltage shift to digital
lines in the on state as various lines change between the on/off states.
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BTH-1208LS-OEM User's Guide

Functional Details

Figure 4. Digital I/O external resistor configuration

Bulkhead signals
The function of the bulkhead pins is explained below.
Battery charging
Use the BATT+, BATT_MID, and BATT– pins to charge two AA or AAA cells used in series, with
BATT_MID connected to the midpoint of the series cells. This enables the charger to detect the voltage of thecells independently in order to stop fast charging when either cell reaches full capacity.
Also you must use the THERMISTOR+ and THERMISTOR– pins to connect to a 10 kΩ thermistor in close
proximity to the battery cells to monitor battery temperature.
External power supply (battery charging not required)
Use the BATT+ and BATT– pins to supply power to the board when battery charging is not required. Power
can be supplied from any DC source in the 1.8 V to 5.5 V range.
Power and pairing control
Use the PWR_SW+ and PWR_SW– pins with an external SPST power switch to turn the board on and off.
Use the PAIRING_SW+ and PAIRING_SW– with a momentary switch to perform the same power and pairing
functionality as the onboard button (refer to Power/pairing button on page 12).
LED control
Use the LED1+ and LED1– pins to connect an external power LED. The series resistor is already on the
BTH-1208LS-OEM; only a LED is required.
Use the LED2+ and LED2– pins to connect an external status LED. The series resistor is already on the
BTH-1208LS-OEM; only a LED is required.
Use the Vbus pin to connect to an external charging LED or to power external circuits from a +5 V supply whena USB host or power supply is present.
Use the CHARGE_LED– pin in combination with the Vbus pin for an external charging LED. The series
resistor is already on the BTH-1208LS-OEM; only a LED is required.

Trigger input
The TRIG_IN pin on connector J2 is an external digital trigger input that you can configure for either
rising/falling edge, or high/low level.

Counter input
The CTR pin on connector J2 is a 32-bit event counter that can accept frequency inputs up to 1 MHz. Theinternal counter increments when the TTL levels transition from low to high.
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BTH-1208LS-OEM User's Guide

Functional Details

GroundThe analog ground (AGND) pin on connector J1 provide a common ground for all analog channels. The ground(GND) pins on connector J2 provide a common ground for the digital, trigger, counter, and power terminals.

Power output
The +VO pin on connector J2 is a 3.3 V output that can source up to 50 mA that is supplied by the power sourceof the device. You can use this terminal to supply power to external devices or circuitry.
Caution! The +V0 pin is an output. Do not connect to an external power supply or you may damage theBTH-1208LS-OEM and possibly the computer.
For more information about signal connections
For more information about analog and digital signal connections, refer to the Guide to DAQ Signal
Connections at www.mccdaq.com/support/DAQ-Signal-Connections.aspx.

Mechanical drawing

Figure 5. Circuit board dimensions

17

Chapter 4

Specifications
All specifications are subject to change without notice.
Typical for 25°C unless otherwise specified.
Specifications in italic text are guaranteed by design.

Analog input
Table 1. Analog input specifications
Parameter

Condition

A/D converter type
Input voltage range for linear operation

CHx to GND

Absolute maximum input voltage
Input impedance
Input current (Note 1)

Number of channels
Input ranges

Throughput (Note 2)

CHx to GND
Vin = +10 V
Vin = 0 V
Vin = –10 V
Single-ended
Differential

Software paced
Continuous scan
BURSTIO

Channel gain queue

Resolution (Note 3)

Differential
Single-ended

Integral linearity error
Differential linearity error
Repeatability
Trigger source

Software-selectable

Pacer source

Software-selectable

Specification
Successive approximation type
Single-ended mode: ±10 V max
Differential mode: –10 V min, +20 V max±25 V max
140 kΩ
70 µA typ–12 µA typ–94 µA typ
8 single-ended or 4 differential; software-selectable±10 V, G=2±20 V, G=1±10 V, G=2
±5 V,
G=4
±4 V,
G=5
±2.5 V, G=8±2.0 V, G=10
±1.25 V, G=16±1.0 V, G=20
Software-selectable
10 S/s typ, system-dependent (Bluetooth)
250 S/s typ, system-dependent (USB)
0.014 S/s to 1024 S/s (Bluetooth)0.014 S/s to 47 kS/s (USB)
0.014 S/s to 47 kS/s to 12K (12,288) sample FIFO
Transfer rate to host is limited to 1024 S/s(Bluetooth)
Software selectable. 8 elements in SE mode,
4 elements in DIFF mode.
One gain element per channel. Elements must be
unique and listed in ascending order.
12 bits, no missing codes
11 bits±1 LSB typ±0.5 LSB typ±1 LSB typ
External digital: TRIG
Software-selectablen Internal
n External (AICKI), rising edge triggered
Software-selectable

BTH-1208LS-OEM User's Guide

Note 1:
Note 2:
Note 3:Specifications

Input current is a function of applied voltage on the analog input channels. For a given input voltage, Vin, theinput leakage is approximately equal to (8.181 * Vin – 12) µA.
Maximum throughput when scanning is machine dependent.
The AD7870 converter only returns 11 bits (0 to 2,047 codes) in single-ended mode.

Accuracy
Table 2. Accuracy, differential mode
Range

Accuracy (LSB)

±20 V
±10 V
±5 V
±4 V
±2.5 V±2 V±1.25 V
±1 V

5.1
6.1
8.1
9.1
12.1
14.1
20.1
24.1
Table 3. Accuracy, single-ended mode

Range

Accuracy (LSB)

±10 V

4.0
Table 4. Accuracy components, differential mode – all values are (±)

Range% of Reading

Gain Error at FS (mV)

Offset (mV)

Accuracy at FS (mV)

±20 V
±10 V
±5 V
±4 V
±2.5 V±2 V±1.25 V
±1 V

0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2

40
20
10
8
5
4
2.5
2

9.766
9.766
9.766
9.766
9.766
9.766
9.766
9.766

49.76629.76619.76617.76614.76613.766
12.26611.766

Table 5. Accuracy components, single-ended mode – all values are (±)
Range% of Reading

Gain Error at FS (mV)

Offset (mV)

Accuracy at FS (mV)

±10 V

0.2

20

19.53139.531

Noise performance
Table 6. Noise performance, differential mode
Range

Typical counts

LSBrms

±20 V
±10 V
±5 V
±4 V
±2.5 V±2 V±1.25 V
±1 V

3
3
3
4
5
7
10
12

0.45
0.45
0.45
0.61
0.76
1.06
1.52
1.82

19

BTH-1208LS-OEM User's Guide

Specifications

Table 7. Noise performance, single-ended mode
Range

Typical counts

LSBrms

±10 V

6

0.91

Analog output
Table 8. Analog output specifications
Parameter

Condition

Specification

Resolution

12-bits, 1 in 4,096

Output range

0 V to 2.5 V

Number of channels

2

Throughput (Note 2)
Power on and reset voltage

Software paced
USB operation
Bluetooth operation

Output current drive
Slew rate

Each D/A OUT

10 S/s single channel typ, PC dependent
Initializes to 000h code
The outputs can be individually configured toinitialize to 000h or to have user configurable
values written to the outputs when the Bluetooth
host is connected or disconnected.
5 mA source capability
0.75 V/ µs typ

Table 9. Analog output accuracy, all values are (±), accuracy tested at no load
Range

Accuracy (LSB)

0 V to 2.5 V

8.0 typ, 73.0 max
Table 10. Analog output accuracy components, all values are (±)

Range
0 V to 2.5 V
Note 4:% of FSR

Gain Error at FS (mV)

Offset (mV)

Accuracy at FS (mV)

0.16 typ,1.44 max

4.0 typ, 36.0 max

1.0 typ, 9.0 max (Note 4)

5.0 typ, 45.0 max

Zero-scale offsets may result in a fixed zero-scale error producing a dead-band digital input code region. In thiscase, changes in digital input code at values less than 0x040 may not produce a corresponding change in the
output voltage. The offset error is tested and specified at code 0x040.

20

BTH-1208LS-OEM User's Guide

Specifications

Digital input/output
Table 11. Digital I/O specifications
Parameter

Specification

Digital typeOutput value mapping

3.3 V open drain
0 written: output drives to DGND
1 written: output is pulled up to 3.3 V via internal resistor
8
Individually configurable
0 V to 5.5 V
47.5 kΩ pull-up resistors (to 3.3 V), 2.2 kΩ series resistors
2.0 V min
5.5 V absolute max
0.8 V max
–0.5 V absolute min
0 V recommended min
0 V to 3.3 V (no external pull up resistor)
0 V to 5.5 V max (Note 6)
1.0 µA typ

Number of I/O (Note 5)
Configuration
Input voltage range (Note 6)
Pull up/pull-down configuration
Input high voltage threshold
Input high voltage limit
Input low voltage threshold
Input low voltage limit
Output voltage range
Output off state leakage current(Note 7)
Sink current capability
Transistor on resistancePower on and reset state

Note 5:Note 6:Note 7:50 mA max (continuous) per pin
0.7 Ω max
USB operation: All input
Bluetooth operation: The digital I/O can either be all input at power on/reset or may
be configured to have user-configurable patterns written to the DIO when theBluetooth host is connected or disconnected.

Each transistor source pin is internally connected to DGND.
The external pull-up is connected to the digital output bit through an external pull-up resistor. Adding an
external pull-up resistor connects it in parallel with the internal 47.5 kΩ pull-up resistor of that particular digital
input/output bit. Careful consideration should be made when considering the external pull-up resistor value andthe resultant pull-up voltage produced at the load.
Does not include the additional leakage current contribution through the internal or any external pull-up resistor.

21

BTH-1208LS-OEM User's Guide

Specifications

External trigger
Table 12. Digital trigger specifications
Parameter

Specification

Trigger source
Trigger mode

External digital; TRIG terminal
Software configurable for edge or level sensitive, rising or falling edge, high or low
level.
10 µs max
1 µs minSchmitt trigger, 47 kΩ pull-down to ground0.76 V typ
0.4 V min
1.2 V max
1.74 V typ
1.3 V min2.2 V max
5.5 V absolute max
0.98 V typ
0.6 V min
1.5 V max
–0.5 V absolute min
0 V recommended min

Trigger latency
Trigger pulse width
Input type
Schmitt trigger hysteresis

Input high voltage threshold

Input high voltage limit
Input low voltage threshold

Input low voltage limit

External clock input
Table 13. External clock input specifications
Parameter

Specification

Terminal nameTerminal type
Input clock rate
Clock pulse width
Input type
Schmitt trigger hysteresis

AICKI
Input
50 kHz, max
1 µs minSchmitt trigger, 47 kΩ pull-down to ground0.76 V typ
0.4 V min
1.2 V max
1.74 V typ
1.3 V min2.2 V max
5.5 V absolute max
0.98 V typ
0.6 V min
1.5 V max
–0.5 V absolute min
0 V recommended min

Input high voltage threshold

Input high voltage limit
Input low voltage threshold

Input low voltage limit

22

BTH-1208LS-OEM User's Guide

Specifications

CounterTable 14. Counter specifications
Parameter

Specification

Pin name
Counter type
Number of channels
Input type
Input source
Resolution
Maximum input frequency
High pulse width
Low pulse width
Schmitt trigger hysteresis

CTR
Event counter
1
Schmitt trigger, 47 kΩ pull-down to ground, rising edge triggered
CTR screw terminal
32 bits
1 MHz
500 ns min
500 ns min
0.76 V typ
0.4 V min
1.2 V max
1.74 V typ
1.3 V min2.2 V max
5.5 V absolute max
0.98 V typ
0.6 V min
1.5 V max
–0.5 V absolute min
0 V recommended min

Input high voltage threshold

Input high voltage limit
Input low voltage threshold

Input low voltage limit

MemoryTable 15. Memory specifications
Parameter

Specification

FIFO
Non-volatile EEPROM

12K (12,288) samples
2,048 bytes (768 bytes calibration, 256 bytes user, 1,024 bytes firmware use)

Microcontroller
Table 16. Microcontroller specifications
Parameter

Specification

Type

High performance 16-bit RISC microcontroller

23

BTH-1208LS-OEM User's Guide

Specifications

Power
Table 17. Power specifications
Parameter

Condition

Specification

Supply current, USB source

During enumeration
After USB enumerationor connected to USB
charger / supply< 100 mA
< 500 mA

Battery power (Note 8)
Battery charging
Battery replacement+VO power available+VO output current
Note 8:After USB enumeration
or Bluetooth connection
After USB enumeration
or Bluetooth connection

Two AA cells
Alkaline and NiMH cells supported
NiMH charging supported.
Alkaline cells automatically detected and not charged.
Replace NiMH cells with Panasonic HHR-10AAB only.
Replace Alkaline cells with Energizer E91 orequivalent.
3.3 V nominal
50 mA max

When operating from batteries there is a user configurable power-off timer that will turn the device off when
there is no host connection for the specified amount of time. The timer can be disabled or set to a value from 1
to 255 minutes.

Bluetooth
Table 18. Bluetooth specifications
Parameter

Specification

Device type (Note 9)
Device compatibility
Bluetooth profile
Radio range

Bluetooth 2.1
Backwards compatible with Bluetooth 2.0, 1.2, and 1.1
Serial Port Profile (SPP)
Class II, 10 m typ

Note 9:The Bluetooth radio is disabled when the device is connected to a USB host.

USB
Table 19. USB specifications
Parameter

Specification

Device type
Device compatibility

USB 2.0 full speed
USB 1.1, USB 2.0

Environmental
Table 20. Environmental specifications
Parameter

Specification

Operating temperature range
Storage temperature range
Humidity

0 °C to 50 °C–40 °C to 70 °C
0% to 90% non-condensing

24

BTH-1208LS-OEM User's Guide

Specifications

Mechanical
Table 21. Mechanical specifications
Parameter

Specification

Dimensions (L × W × H)
USB cable length
User connection length

99.06 × 68.58 × 14.61 mm (3.90 × 2.70 × 0.58 in.)3 m (9.84 ft) max
3 m (9.84 ft) max

Signal connectors
Table 22. Header specifications
Parameter

Specification

Connector typeThree 2 × 8 pin, 0.1 in. pitch headers

Analog signals (J1)
Table 23. 4-channel differential mode pinout
Pin
1
3
5
7
9
11
13
15

Signal name
CH0H
CH0L
CH1H
CH1L
CH2H
CH2L
CH3H
CH3L

Pin description
Analog input 0 HI
Analog input 0 LO
Analog input 1 HI
Analog input 1 LO
Analog input 2 HI
Analog input 2 LO
Analog input 3 HI
Analog input 3 LO

Pin
2
4
6
8
10
12
14
16

Signal name
AGND
AGND
AGND
AGND
AGND
AGND
AOUT0
AOUT1

Pin description
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog output 0
Analog output 1

Table 24. 8-channel single-ended mode pinout
Pin
1
3
5
7
9
11
13
15

Signal name
CH0 IN
CH1 INCH2 IN
CH3 IN
CH4 IN
CH5 IN
CH6 IN
CH7 IN

Pin description
Analog input 0
Analog input 1
Analog input 2
Analog input 3
Analog input 4
Analog input 5
Analog input 6
Analog input 7

Pin
2
4
6
8
10
12
14
16

Signal name
AGND
AGND
AGND
AGND
AGND
AGND
AOUT0
AOUT1

Pin description
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog ground
Analog output 0
Analog output 1

Digital signals (J2)
Table 25. Digital I/O signal pinout
Pin
1
3
5
7
9
11
13
15

Signal name
DIO0
DIO1
DIO2
DIO3
DIO4
DIO5
DIO6
DIO7

Pin description
Digital input/output 0
Digital input/output 1
Digital input/output 2
Digital input/output 3
Digital input/output 4
Digital input/output 5
Digital input/output 6
Digital input/output 7

Pin
2
4
6
8
10
12
14
16

25

Signal name
GND
CTR
TRIG_IN
AICKI
GND
+VO
GND
GND

Pin description
Digital ground
Counter input
Digital trigger input
Pacer input
Digital ground
3.3 V output
Digital ground
Digital groundBTH-1208LS-OEM User's Guide

Specifications

Bulkhead signals (J3)
Table 26. Bulkhead signal pinout
Pin
1

Signal name
BATT+

3
5

BATT_MID
THERMISTOR+

79PWR SW+PAIRING SW+

11
13
15

LED1+
LED2+
Vbus

Pin description
Battery input positive(2 AA/AAA cells)
Battery center tap
10 kΩ thermistor positive(battery temperature sensing)
SPST contact 1 (power switch)
Momentary contact 1 (pairing /soft power switch)
LED1 anodeLED2 anodeUSB 5 V supply (charging LED
anode)

26

Pin
2

Signal nameBATT-

Pin description
Battery input negative

4
6

GND
THERMISTOR-

Ground10 kΩ thermistor negative

8
10

PWR SWPAIRING SW-

SPST contact 2
Momentary contact 2

12
14
16

LED1LED2CHARGE LED-

LED1 cathodeLED2 cathode
Charging LED cathodeMeasurement Computing Corporation
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Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com

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