MOD-RFID125
User Manual

All boards produced by Olimex are ROHS compliant

Rev.A, February 2008

Copyright(c) 2008, OLIMEX Ltd, All rights reserved

INTRODUCTION:
MOD-RFID125 is an RFID station, able to read Manchester-encoded 64-bit
EM4102 tags with 64 periods of carrier frequency per data bit. All thecomplexity of RFID tag detection, verification and decoding are handled by
MOD-RFID125. After it strips the header and the checksums user is given
the 40-bit ID of the transponder tag.
MOD-RFID125 supports three distinctive modes of operation, easily
switched by a single button press. It can emulate USB HID keyboard andinput the read TAG ID directly to any Windows application, including thevenerable Notepad. Or it can emulate USB CDC serial port for easy accessfrom custom user applications using standard code for COM port access.
The third option allows access from any standard 5V UART, allowing easy
integration with existing microcontroller applications.

FEATURES:-Supports Manchester-encoded 64-bit EM4102 RFID tags with 64
periods of carrier frequency per data bit;Base RFID frequency 125kHz;
USB port connection to PC;
Standard 5V UART 9600,8N1 connection to user microcontroller
boards;Three modes of operation, easily changed by pressing the button;
USB HID keyboard emulation mode;
USB CDC serial port emulation mode;
UART connection mode;
Simple command-line interface in USB CDC and UART modes forconfiguration and data acquisition;
Two LEDs indicating device status and tag presence;
Support for continuous and periodic RF scanning to better suit user
power requirements;
Ships with default mode USB HID and default configuration:
continuous read, scan always, one report per second, LEDs activated;

ELECTROSTATIC WARNING:
The MOD-RFID125 board is shipped in protective anti-static packaging.
The board must not be subject to high electrostatic potentials. Generalpractice for working with static sensitive devices should be applied whenworking with this board.

REQUIREMENTS:
Cables: 1.8 meter USB A-B cable.
Power: External 6-9V DC power supply (applicable only for MOD-RFID125BOX in UART mode).
Software:
Software needed for USB HID keyboard mode:- Notepad or other text editor.
Software needed for USB CDC and UART modes:

-HyperTerminal or other terminal program.

SUPPORTED RFID TAGS:
MOD-RFID125 supports RFID transponder tags
characteristics:- Based on EM4102 chip;- 125kHZ carrier frequency;- 64-bit ROM, continuously transmitted;- 64 periods of carrier frequency per data bit;
- Manchester encoding;withthefollowing

UEXT CONNECTOR SCHEMATICS (only for MOD-RFID125-BOX):pin
123Abbrev.
NC
GND
RXD

4TXD

5678910NC
NC
NC
NC
NC
NC

UEXT
description
Not Connected
GroundUART Receive Data (MOD-RFID125input)
UART Transmit Data (MOD-RFID125output)
Not Connected
Not Connected
Not Connected
Not ConnectedNot Connected
Not Connected

POWER SUPPLY:

Normally the device is supplied from USB.
MOD-RFID125-BOX can be connected to external 6-9V DC power supply.
This can relief the USB hub power supply when device is in USB HID orUSB CDC mode. External power supply is mandatory for UART mode ofoperation.

POWER SUPPLY CABLE CONNECTION
Connect to...

Pin1+6-9V DC2GNDLEDS:

In normal mode the GREEN LED is on whenever the RF antenna circuit isactive and scanning for RFID tags. The RED LED switches on whenever avalid RF TAG ID is being scanned and decoded successfully.
The LEDs can be switched off to save power consumption. See the“Command Line Interface” section for more information.
In boot loader mode the LEDs have other meaning. See the “FirmwareUpgrade” section for more information.

PC DRIVER INSTALLATION:

Drivers for the USB HID mode are integrated in Windows XP/Vista.
The driver for USB CDC mode is available from our website. Windows
installation steps are the following:
1. Download and unzip the file “MOD-RFID125-drivers.zip” in atemporary directory.
2. Plug the programmer in the USB port.
3. Point the Device Wizard to the temporary directory.
4. Windows will complain that drivers are not signed. Click “Continue”.
5. Click finish.
Screen shots of the steps are shown below:

Linux distributions normally include drivers both for USB HID and USB
CDC classes. Depending on which driver is loaded in the kernel, user
should look either for/dev/ttyACMn
or/dev/ttyUSBn
where "n" is a number, assigned by the kernel to the plugged device.

USB HID MODE:
When device is connected via USB to a host PC it will represent itself as
USB HID keyboard. When an RFID transponder is detected in the vicinity,
the module will type the HEX-representation of the transponder ID.
To use the device in this mode:
1. Open Notepad.
2. Plug in the device in the USB port of the PC.
3. Put an RFID tag in front of the device. The TAG ID will be entered in
the currently opened text file.
There is no need for OS driver because all major operating systems include
USB HID drivers.
NOTE: This mode does not allow configuration of device parameters. MODRFID125 is shipped with default configuration for continuous read and one
second repeat. If this must be changed then device must be switched toUSB CDC mode and configured using the serial command line interface.

USB CDC MODE:
In this mode the device represents itself as USB CDC virtual serial port. It
provides a simple shell-like command line interface for configuring andinteracting with the module. The device echoes back the typed charactersand waits for Carriage Return (Enter) before processing the line input. See“Command Line Interface” for more information on the supportedcommands.
Any terminal software can be used to open the COM port, assigned by theOS, and type in commands.

UART MODE:
In this mode there is no need for USB connection. Instead the device must
be connected via UEXT connector to a TTL-level UART of a microcontroller
system of choice. It expects the peer to be configured with 9600 bps, 8bit
character, no parity, 1 stop bit. The communication is otherwise the sameas in USB CDC mode, but there is no need for USB. Again, all enteredcharacters are echoed back.

SWITCHING OPERATING MODES:The current mode of operation can be selected by pressing and holding thebutton of the device. After two seconds the LEDs will start to blink and willshow the code for the next selected mode. When button is released, thedevice will reboot and enter the selected mode. Selected mode isremembered between power downs. The assigned codes are:
LED Status
RedGreen

Description
Previous State

State After Button Is
Released

blinksoff

UART

USB HIDoffblinksUSB HIDUSB CDCblinksblinksUSB CDCUART

COMMAND LINE INTERFACE (USB CDC and UART modes):The command line interface, available in USB CDC and UART modes,
allows device configuration and reading of successfully decoded TAG IDs.
Just open the serial port assigned to MOD-RFID125 using HyperTerminalor similar terminal program, and start typing commands.
For the impatient: type '?' and press enter to see a short help for the
supported commands. Any typed character will be echoed back; 'enter' will
force the module to process the input command line.
1. Command ?
This command prints a short help message, describing the available
commands and their arguments.
2. Command iThis command prints a short information about firmware version,
hardware board revision, and currently selected configuration.
3. Command b
This command forces the device to enter boot loader mode. After
executing this command the device will disconnect itself from USB,switch to boot loader mode, and reconnect itself in anticipation ofreceiving a firmware upgrade image. See the section “FirmwareUpgrade” for more information.

4. Command r
This command is only valid if device is in single read mode (seebelow). It will trigger a single TAG read. If TAG ID is successfullyread, it will be printed. Otherwise if operation timed out, zeros will
be printed.
5. Command msXX
Set single read mode. The XX parameter must be a decimal value,indicating the TAG read timeout in seconds.
Example – setting single read mode with 15 seconds timeout:
ms15
6. Command mcFR
Set continuous read mode with frequency F (Hz) and repeat reportinterval R (seconds). Both F and R must be single digit decimalnumbers.
If F is 0 then RF antenna is constantly switched on and the device isscans continuously for tags. Otherwise if F is 1-5, the device willswitch the antenna on F times per second.
If R is 0 then a successfully read RF tag ID is reported only once.
Otherwise if R is 1-9, the device will report the tag ID every R
seconds until the tag is seen in the proximity.
Example – continuous scanning, single report per seen tag:mc00
Example – scan once per second, single report per seen tag:mc10
Example – scan twice per second, report a seen tag every second:
mc21
Example – continuous scanning, report a seen tag every 5 seconds:
mc05
7. Command mlE
Set LED mode. If E is 0, LEDs will be disabled. Otherwise if E is 1,LEDs will be enabled.
Example – enabling LEDs:
ml1
Example – disabling LEDs to conserve power:
ml0
Below is a screen shot of command line session using HyperTerminal:FIRMWARE UPGRADE:
MOD-RFID125 contains a built-in boot loader for easy firmware upgrade.
Device enters boot loader mode if the application FLASH section iscorrupted. To force the device to enter boot loader mode for manual
firmware update do the following:
1. Disconnect the device from any power source (external DC, USB).
2. Press and hold the button.
3. Power up the device by connecting it to USB.
4. Device now must be in boot loader mode, indicated by the LED lightsequence:a. RED on, GREEN off.
b. RED off, GREEN on.
c. RED off, GREEN off.
Button can now be released. The device will stay in boot loader mode until
it is power cycled.
Boot loader implements the standard protocol XMODEM with CRC16 forfirmware update. User is free to use his favorite terminal client(HyperTerminal, minicom, etc) to upload the firmware images taken fromour website. Boot loader uses an USB virtual serial port that is baudrateagnostic.
As an alternative we provide a simple Windows GUI application for users
who don’t want to or cannot use terminal software.
After the firmware image is uploaded the target will blink the GREEN LED if
update was successful, otherwise it will blink the RED LED if firmware
image was invalid or update was unsuccessful. Device stays in this state
until it is power cycled.
WARNING: Upgrade from UEXT via UART is NOT supported! Boot loader
supports only USB.

ELECTRICAL CHARACTERISTICS:
SymbolDescriptionCondition

MinTypMax

Units

4.5

55.5

V

VCC

Power Supply Voltage.

ICC,NOLE

Power Supply Current Idle (RF scanning not active)
with deactivatedContinuous scanning
LEDs.

20mA

120mA

Scanning 2 times per second

36mA

Power Supply Current Continuous scanningwith activated LEDs.
Scanning 2 times per second

130mA

40mA

DICC

ORDER CODE:
MOD-RFID125 – assembled and tested (no kit, no soldering required)
MOD-RFID125-BOX – assembled and tested (no kit, no solderingrequired)

How to order?
You can order to us directly or by any of our distributors.
Check our web www.olimex.com/dev for more info.

Revision history:
REV.A- create April 2008

Disclaimer:© 2008 Olimex Ltd. All rights reserved. Olimex®, logo and combinations thereof, are registered trademarks ofOlimex Ltd. Other terms and product names may be trademarks of others.
The information in this document is provided in connection with Olimex products. No license, express or impliedor otherwise, to any intellectual property right is granted by this document or in connection with the sale of Olimex
products.
Neither the whole nor any part of the information contained in or the product described in this document may beadapted or reproduced in any material from except with the prior written permission of the copyright holder.
The product described in this document is subject to continuous development and improvements. All particulars of
the product and its use contained in this document are given by OLIMEX in good faith. However all warranties
implied or expressed including but not limited to implied warranties of merchantability or fitness for purpose areexcluded.
This document is intended only to assist the reader in the use of the product. OLIMEX Ltd. shall not be liable forany loss or damage arising from the use of any information in this document or any error or omission in suchinformation or any incorrect use of the product.