hybridfree/eevblog-posts huggingface dataset:
Dac - 16 bit; 0-5V - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: March 07, 2015, 03:24:59 pm
content: I am looking for 16 bit dac & 16 channel with 0-5V.Also application is battery powered, so I need DAC to put in sleep when not required.I had found this octal dac;low power from TI DAC8568 with SPI interface.Its 8 channel so I need to use two dacs in parallel. But I didn't find CS pin there.Is there any other alternative to use 2 dacs in parallel . I have only one SPI in my MCU.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 07, 2015, 03:31:43 pm
content: You can use the /SYNC input as a chip select.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: March 08, 2015, 02:09:05 pm
content: Thanks
DAC controls with pull-up and pull-down resistors - Page 1
Forum section: electronics / beginners

author: jmf11
author_rank: Contributor
timestamp: November 25, 2024, 09:19:00 pm
content: Hello,I'm working on a 8 channels DAC based on the ESS ES9080. I'm puzzled with the Evaluation board schematics that implements pull-up and pull-down resistors on the different signals: see attached picture.OK the pull-up is "open" but I don't grasp why they implement this on the board and why they don't just implement the pull-down.What could be the rationale?Datasheet:https://www.esstech.com/wp-content/uploads/2022/09/ES9080_DS_v0.4.3.pdfBest regards,JMF

author: Buriedcode
author_rank: Super Contributor
timestamp: November 25, 2024, 09:25:59 pm
content: I assume they added the footprints to allow different default behavior. Some MCU's tristate their IO during reset, so to ensure IO's have a known state they need a pull up/down. Different interfaces will want a different state, for example different SPI modes have the clock lines idle high, or low.I'm assuming these are on the I2S lines - I'm unsure why they would require pull-ups instead of pulldowns.

author: jmf11
author_rank: Contributor
timestamp: November 26, 2024, 06:24:43 pm
content: Thanks for your reply,Yes it is mostly I2S and general pupose IO. Your reply helps me simplify the schematic and remove the optional pull-up.Best regards,JMF
DAC input in feedback of Opamp. - Page 1
Forum section: electronics / beginners

author: Sam__
author_rank: Regular Contributor
timestamp: January 17, 2014, 12:05:40 pm
content: I just had a very stressful pre job interview question which was to analyse a circuit. I came across something I'd never seen before (exactly what you want to happen right?).There was a DAC input where there is usually a ground on a non-inverting amp.Here's the diagram.I was wondering what effect that has on the circuit and why it's useful?

author: miceuz
author_rank: Frequent Contributor
timestamp: January 17, 2014, 12:15:31 pm
content: errr.... to center the output of an opamp to a different point set by dac?

author: ThomasDK
author_rank: Regular Contributor
timestamp: January 17, 2014, 04:15:46 pm
content: Quote from: miceuz on January 17, 2014, 12:15:31 pmAKA adding an offset

author: Sam__
author_rank: Regular Contributor
timestamp: January 17, 2014, 04:17:46 pm
content: So the output of the opamp has an adjustable offset due to the DAC input?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: January 17, 2014, 04:43:09 pm
content: Sam,Think of it this way:If pin 3 the positive input was grounded. You are left with the inverting amplifier configuration. From DAC3 to the op-amp output the gain is:Vout / DAC3 = -1 x R40/R43So this can be used for setting an offset.Look up 'superposition theorem'.Jay_Diddy_B

author: Sam__
author_rank: Regular Contributor
timestamp: January 17, 2014, 05:13:37 pm
content: Quote from: Jay_Diddy_B on January 17, 2014, 04:43:09 pmThanks a lot. I'll get reading!

author: AlfBaz
author_rank: Super Contributor
timestamp: January 17, 2014, 09:54:19 pm
content: Quote from: Sam__ on January 17, 2014, 04:17:46 pmIs it any clearer if you called it a DAC output?

author: Sam__
author_rank: Regular Contributor
timestamp: January 17, 2014, 10:01:05 pm
content: Quote from: AlfBaz on January 17, 2014, 09:54:19 pmoutput from the DAC... input to that part of the circuit from the DAC. all the same really. But I do understand what's going on now. Thanks a lot guys.

author: cellularmitosis
author_rank: Unknown
timestamp: January 18, 2014, 12:02:55 am
content: it took my brain a moment to reason out why this creates an offset, rather than actually changing the gain.a naive conclusion would be that the DAC changes the gain, because the voltage divider created by the resistors is simply creating an input voltage, and the DAC can push that voltage around.however, a second glance reveals that the voltage divider is not creating a fixed voltage, it follows the AC signal. since the DAC just offsets by a fixed amount, and does not follow the AC signal, it cannot be modifying the gain, only creating an offset.do I have that right?

author: Rudane
author_rank: Regular Contributor
timestamp: January 18, 2014, 01:41:15 am
content: The input to the inverting input will experience the gain -100k/100k which is -1. So, the DAC voltage gets inverted and adds a constant value to the output signal. The non-inverting input will experience the gain 100/100 + 1 or 2. So the output will be 2*Vin+ - DAC.
DAC noise problem with SPI - Page 1
Forum section: electronics / beginners

author: erazedfx
author_rank: Newbie
timestamp: August 20, 2019, 03:14:24 pm
content: Hi every one, it’s my first time posting here.Recently I’ve been learning about DAC and ran into some noise problems. I’m using a STM32F303K8 board to drive a LTC1660CN DAC via SPI. The DAC is outputting a ramping waveform.The problem is, every time SPI_CS pin is pulled down by the controller, it creates a voltage spike on the DAC output as well. (As you can see in the picture below)What i’ve tried :1 Configuring the SPI_CS pin on the controller to Pulled Up/Pulled Down/No PUPD2 Add capacitors between ground and VCC/Data In/SPI_CLK near the DAC chipSo far I discovered that putting a 10uF capacitor between the DAC output and ground does help to reduce the noise, but I doubt that this is the correct method. Other than that nothing seems to help.My question is, is this a problem can be solved?Thank you for your time and help.(In this picture, yellow = SPI_CS Pin, blue = DAC out A)

author: radiolistener
author_rank: Super Contributor
timestamp: August 20, 2019, 03:32:05 pm
content: it looks like power line filtering or power supply issue. Try to use separate power line and separate ground for analog circuits. Add ferrite bead and low pass filter with uF capacitors on analog power line. Also add nF caps as close as possible to the chip for analog power/ground lines. Place analog wires as far as possible from digital wires.

author: ggchab
author_rank: Frequent Contributor
timestamp: August 20, 2019, 04:19:18 pm
content: You can try to slow down the rise and fall times of the signals on the bus by adding resistors between the processor and the bus lines. The processor may have an option that has the same effect.

author: erazedfx
author_rank: Newbie
timestamp: August 20, 2019, 07:06:04 pm
content: Thank you guys, I found the cause (and the solution) of the problem.I tried to replace the mcu with arduino and suddenly everything works fine. After some checking it turned out that it's the SPI settings on stm32 that I messed up. After I set 'Clock Polarity' to 'Low' then everything works great!Hope this can help someone on the Internet who runs into the same problem.
DAC Offset Compensation - Page 1
Forum section: electronics / beginners

author: bitshift
author_rank: Regular Contributor
timestamp: August 14, 2015, 08:37:00 am
content: Hey guys,I'm using a Microchip 12 bit DAC (MCP4921) in a project I'm working on. I'm using a 2.048V reference to give an LSB of 0.5mV.It's working great but according to the datasheet, the DAC has an offset error of 1% of the full scale range. With the 2.048V reference this can be roughly as high as 21mV. In practice I've measured an offset error of about 1.5mV.The output of the DAC goes into a voltage follower. I then use the following circuit to compensate for the offset voltage of the op amp:So my question is, how do I compensate for the offset voltage of the DAC?

author: SeanB
author_rank: Super Contributor
timestamp: August 14, 2015, 07:30:47 pm
content: Set an output of 0V, then adjust pot for that voltage. Simple enough, though you probably will want to have a gain trim as well for the full scale as well, either by having a small offset on the reference or a adjustment on the DAC. Even more tricky is having a bipolar output and adjusting for that to be monotonic and equal for both full scale values.
Daft Question : RE hearing devices - Page 1
Forum section: electronics / beginners

author: electroniceddy
author_rank: Newbie
timestamp: May 28, 2020, 12:31:33 am
content: Hi all,Just a quick daft question, are there any devices out there that can recieve sounds above the human range IE 20khz - 160khz and transform them to the human range so that one can hear them, If not is it possible to create something that would do that..Really im looking for something like a radio, where i can tune the frequency into the device and listen to what was on that frequency?Is it possible? and if so how would one go about this..cheerskeith

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 28, 2020, 12:45:39 am
content: https://www.elektormagazine.com/magazine/elektor-200709/18626etc

author: Andy Watson
author_rank: Super Contributor
timestamp: May 28, 2020, 02:10:05 am
content: Search for bat detectors.Like this:http://www.magenta2000.co.uk/

author: mikerj
author_rank: Super Contributor
timestamp: May 28, 2020, 07:50:32 am
content: This is realisable in a reasonably fast micro with a suitable internal or external ADC and DAC. TheTeensy dev boardshave a fairly extensive audio library which does all the hard work for you, and it'sbeen done already.
Daisy chain LED intensity control for strip - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: January 04, 2021, 05:57:50 am
content: 1. Need to control led string in daisy chain with intensity control of each led like in led strips.2. Each led will consume max of 300mA, so for linear intensity control we need to control led for 0 to 100%. All leds are single color led's not RGB type.3. I checked TLC5973, but it has max control for 50mA per channel, i.e 150mA per IC. Is their any daisy chain IC where there is control of upto 300mA current? Need control of 50 led in daisy chain, with each led's linear inensity control

author: sigma_xi
author_rank: Contributor
timestamp: June 11, 2021, 05:59:01 pm
content: You could use one transistor for each LED and get some PCA9685 PWM controllers to perform the dimming.
Daisy-chain MAX6954 - Page 1
Forum section: electronics / beginners

author: PinheadBE
author_rank: Regular Contributor
timestamp: June 11, 2023, 01:12:28 pm
content: Hi,I have a project where I will daisy chain several MAX6954'sHere is the DS:https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6954.pdfIt appears so simple that I didn't give it a second thought..... until I found this comment on a github repository:https://github.com/AnthonyDiGirolamo/MAX6954QuoteI wonder what the problem could be, what precautions I could take to avoid problems (insert a Schmitt-triggered buffer at the DIN input of the second chip perhaps ? Keep a relatively low speed in the communication ?)....I unfortunately didin't find a way to contact the guy.....Since I have 8 MAX6954 chained, I could also add 3 address lines from my MCU and a 74x138 decoder, but this would complicate my PCB layout which is already a 4-layer heavily populated PCBIdeas welcome

author: barshatriplee
author_rank: Regular Contributor
timestamp: June 11, 2023, 01:51:39 pm
content: Ensure that each MAX6954 device receives a stable and clean power supply. Any fluctuations or noise on the power lines can affect the device's performance and communication reliability. Consider using appropriate decoupling capacitors and filtering techniques to maintain stable power.

author: PinheadBE
author_rank: Regular Contributor
timestamp: June 11, 2023, 03:28:48 pm
content: That will be the case: I will put 5 decades of decoupling caps on the power lines: 10 nF, 100 nF, 1 µF, 10 µF and 100 µF close to each chip and a bulk cap of 1000 µF directly after the power regulator, which is a linear LDO regulator (+ 100 nF everywhere where usually needed)Besides, in the Github project mentionned above, a clock speed of "only" 1 MHz is used. The MAX6954 can go as high as 26 MHz. Which is why I find it so weird that he is having trouble. On the other hand, he doesn't use a PCB but wire-wrapped connections..... I wouldn't have done that, but I'm not blaming anyone, of course: 7 years ago, it wasn't not yet so easy to grab cheap PCB built in small quantities for hobbyists.In my application, I even don't need to go up to 1 MHz, since there will be no fancy effects.Has anyone got any experience with that chip ?
Daisy Chain Solar Garden Lights - Page 1
Forum section: electronics / beginners

author: themrmurray
author_rank: Newbie
timestamp: June 15, 2018, 11:34:33 am
content: Hi all,I have 2 sets of solar powered fairy string lights which I would like to wiring together into one unit.Each strand has a solar unit with a rechargable battery, pretty standard garden light engineering.Is it as simple as soldering the two solar panels in series to combine and power the strips as one?

author: innkeeper
author_rank: Unknown
timestamp: June 23, 2018, 03:07:58 am
content: Hi and welcome to the forum.That would really depend on how its all wired. I'm doubtful it would be as simple as you describe.what would be the goal in connecting them together anyway?
DALI2 Project PIC32MX - Page 1
Forum section: electronics / beginners

author: walflucaa
author_rank: Newbie
timestamp: November 10, 2022, 02:02:00 pm
content: Good evening everyone!I am working on a project with a DALI2 ballast. The aim of the project is to create a small prototype of a smart LED luminaire, controllable via PC. In order to make this prototype, I've been using a mikroe board (https://www.mikroe.com/clicker-2-pic32mx) together with their click board (https://www.mikroe.com/dali-2-click) that allows to use the DALI protocol to control ballasts.My question is related to mikroe programming tools and libraries, if anyone is familiar with them, since I've not been able to find help anywhere, not even on their website.They provide a library for DALI2 (https://libstock.mikroe.com/projects/view/2333/dali-2-click), with some examples attached that allow to turn on/off and dim the light, which I have tried and work perfectly. They also provide a compiler, called mikroC, which I have used to build the code. Now I'd like to improve the project and "ask" data to the DALI2 ballast connected to the board (something that the DALI protocol allows you to do), like lamp failure or on-off status or power level and so on. Coding is not my strength, so I'm sorry for the long question.I have noticed in the dali.c and dali.h folders available on github, which are part of the library mentioned previously, that there is a function which allows to "grab" data from a buffer on the board and to write it somewhere (?)The function is dali2_getBallastResponse(); (https://github.com/MikroElektronika/DAL... 2_driver.c)Does anyone know what kind of data this function gets access to, and how can i read it (maybe on a txt file or print it on screen)? Or if there are any other ways in which I can query the ballast's data and read the answer?Thank you for your help!
Damage to a Guitar Pedal - Page 1
Forum section: electronics / beginners

author: eev_carl
author_rank: Regular Contributor
timestamp: January 10, 2019, 04:33:11 am
content: Hi,I was checking out the waveforms on some of my bass guitar effects pedals and think I damaged one. I have a HomeBrew Electronics boutique overdrive / preamp. I had plugged a bass in the input and broke out the output so that the tip and sleeve went to an oscilloscope. I did this with several other pedals and was able to compare the different clipping waveforms.Could a setup like this damage the pedal? The pedal doesn't turn on anymore (other ones that underwent the same test do still function). I used the same power adapter that I use during normal operation so I don't think there's a polarity problem with the supply.Thanks,Carl

author: Buriedcode
author_rank: Super Contributor
timestamp: January 10, 2019, 05:06:44 am
content: It is unlikely that hooking it up to the scope like you said would damage the pedal, and even more unlikely that shorting the output would damage it. Most overdrives only contain diodes, transistors or opamps, so not much to go wrong, although these can be killed given the right conditions. The most common faults with guitar pedals are the mechanics - connectors, switches, broken knobs, stuff that takes the abuse.When you say "it doesn't turn on" do you mean no signal output, or no indicator LED or both? Most pedals these days are true-bypass, but are turned on by plugging in the input jack (the socket is stereo, so switches to ground). Also because of ground loops, DC jacks tend to be reverse polarity, which means if you use a DC socket that electrically connects to the metal case, the case can be at +9V rather than the 0V. I suppose that connecting to a transistors base could fry one, but again its very unlikely thats whats happened, I'm just guessing.A schematic and maybe even a photo would be helpful

author: floobydust
author_rank: Super Contributor
timestamp: January 10, 2019, 05:21:18 am
content: What is your power supply for the pedals?A (two-prong) SMPS wall-wart will float at ~60V due to the Y-capacitor.Pedals usually get 9VDC power floating with respect to earth-ground. You can prove this by measuring ACV from guitar sleeve to earth-ground. It's not enough leakage current to give you a tingle but it can damage an IC if you hot-swap in the output jack to something earth-grounded like an oscilloscope.The (pedal) tip touches earth-ground and a discharge occurs.The other way to damage a (not well designed) pedal- shorting the tip to GND can do it if the output cap has a charge on it.
Tolerance question - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: April 30, 2020, 03:37:32 pm
content: I was just replacing a volume pot. It was 20k value, so i didn't have a lot of options available to buy new. I ended up getting one with a different pinout from the original. I noticed the right channel is louder than the left channel by about 50%.At maximum volume, the right channel is topping out at about 16k ohms and the left channel at 20k ohms as it should be. I'm not sure, could i have damaged the pot, because i thought 20% tolerance for a stereo potentiometer meant both sides should be matched. Maybe it is just out of spec?

author: Vovk_Z
author_rank: Super Contributor
timestamp: May 01, 2020, 04:32:49 pm
content: There are many versions. I would measure an input resistance of other circuit first.Then, I usually buy two or more potentiometrs to find good one (because of that problem with tolerance and channel equality).

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 01, 2020, 09:36:18 pm
content: You can plaster over this by adding a pad resistor on the end of the lower value pot. I won't make them track, but by picking an appropriate resistor you can make them match at your normal listening level, and they won't be too far off for nearby levels.

author: Shock
author_rank: Super Contributor
timestamp: May 02, 2020, 08:52:11 am
content: If you are using a pot that can be opened you can also make a more matched one from a handful of them as well.
Damn killed uCurrent first time out. Lol - Page 1
Forum section: electronics / beginners

author: veryevil
author_rank: Unknown
timestamp: January 09, 2013, 03:27:26 pm
content: Hey, I just got my first two uCurrents and first time out I think I killed one! Switched it to nA range while drawing about 9uA. Now the voltage output is all screwy (technical term).What do I need to replace to get it working again? Just the MAX4239? Will I have damaged anything else?Is there any over voltage protection that could be placed on the input of the MAX4239?

author: FenderBender
author_rank: Super Contributor
timestamp: January 09, 2013, 11:32:36 pm
content: I don't think there's much proteciton on it because it will screw with the burden voltage which needs to stay low.But perhaps something can be done.

author: JoannaK
author_rank: Frequent Contributor
timestamp: January 10, 2013, 12:46:19 am
content: I assume that the diagram at thehttp://alternatezone.com/electronics/ucurrent/uCurrentArticle.pdfis valid.As far as I'm willing to guess, the Max4239ASA+ has blown. Good news is that it's merely couple USD and SO-8 pin out should be user replaceable, if one has any experience of surface mount rework.For the future, adding couple protection diodes (from max4239 pin 3 to supply rails) could perhaps prevent similar mistakes. And as far as I understand those should not affect the normal measurement.Anyone willing to test on their uCurrent ?

author: tld
author_rank: Regular Contributor
timestamp: January 10, 2013, 08:17:05 am
content: Quote from: veryevil on January 09, 2013, 03:27:26 pmWhy would switching it to nA-range kill it?All you're doing is switching from 10kOhm + 10 Ohm to just the 10kOhm sense resistor.That'd make the voltage output all screwy, but only until you change it back to uA range, it shouldn't kill anything?(disclaimer: I haven't had enough coffee to do a decent impersonation of awake yet... )

author: veryevil
author_rank: Unknown
timestamp: January 10, 2013, 08:26:09 am
content: Quote from: tld on January 10, 2013, 08:17:05 amMy guess is that 8uA is 8000nA which is 8 times higher than the 1000nA input range and also is trying to set 8v output.I have no problem with replacing the chips SMD on this scale is easy. Its just which bits, pretty sure just the MAX chip.
DAQ Event Capture and Testing - Page 1
Forum section: electronics / beginners

author: roginutah
author_rank: Newbie
timestamp: December 02, 2020, 01:47:18 am
content: I am looking to record an event with my scope involving up to 4 signals (to be read), have them saved, then reset and continue testing. It will be unattended because it may take days or weeks or... to find the event(s) I'm looking for. I do not need to record the uneventful. Currently have 1054z. If you can get me "up and running", I would appreciate it.Thank you,Rogerps I would also like to know about any signal generation software/hardware that is easily configurable for the same lengthy testing (also 3 or 4 outputs). I'm surethere are better (and reasonably priced) options than the equipment I have(SDG 1025 - and an old laptop), please let me know. Thanks, again.Probably straightforward, I just can't find the info/help I'm looking for.

author: m k
author_rank: Super Contributor
timestamp: December 04, 2020, 10:03:47 am
content: If your signals need an oscilloscope then that should it be, same with the AWG.Maybe you should consider a special purpose circuit.Your gear has a potential for more.What kind of frequencies are in question, can a sincle DAC/ADC MCU do the trick?
DAQ serial connection - Page 1
Forum section: electronics / beginners

author: Drone601
author_rank: Newbie
timestamp: June 09, 2021, 04:48:09 pm
content: Hi all. This is my first ever question here and boy is it a dumb one!I'm looking at using PC-based DAQ software (think LabView, but not) to make a semi-automated PCB test fixture for production runs. The PCB will go onto a bed-of-nails, and I want to use an off-the-shelf 16 relay module to sequentially pick up different nails and direct their corresponding voltages to a benchtop multimeter, which feeds its measurements to the DAQ software for pass/fail judgement. The thing is both the multimeter and the relay module are RS232 controlled. Sooo...here comes the stupid...brace yourselves. Can I somehow connect both of those devices to the PC at once? I see a lot of "NO!" but some "maybe" and a few "sure" out there.

author: RES
author_rank: Regular Contributor
timestamp: June 09, 2021, 06:56:25 pm
content: Just an idea. You need a RS232 to RS485 converter, than you will have an RS485 (2 wire) databus. Than connect two RS485 to RS232 converters on that databus. Use the RTS and CTS lines to toggle the packets (byte by byte) (** unsure if this idea/setup/system can work **)

author: jmelson
author_rank: Super Contributor
timestamp: June 09, 2021, 07:11:51 pm
content: You can get USB to serial "cables" very cheaply. If these work for the type of communications your devices need, that will solve your problem. You can put a bunch of these on one PC.Jon

author: Manul
author_rank: Super Contributor
timestamp: June 09, 2021, 08:59:03 pm
content: It is very normal to have a number of RS232 ("COM") ports on a PC doing independent comms and accessing them all at once from software. So USB to RS232 adapters or a PCI RS232 board (if it is a desktop) will solve the problem nicely.
Darkened Monochrome LCD Display from Air Conditioner Remote Control - Page 1
Forum section: electronics / beginners

author: pinlee
author_rank: Newbie
timestamp: November 16, 2015, 05:46:47 am
content: Hi all, I have this LCD screen from my remote control which has a darken spot that making the screen unreadable. This remote is rather old and the company who manufacture the air-cond was no longer in the business.I wish to replace the LCD but not sure how to get a new one. It has no serial no or so. Maybe I have missed it out somewhere.Thank you, any help is appreciated.

author: ataradov
author_rank: Super Contributor
timestamp: November 16, 2015, 06:19:18 am
content: I'm 99.9% positive that this is a custom LCD and the only way to replace it is to find another remote from the same model.Custom LCDs are almost as cheap to make as the PCBs, so companies making 1000's of units just make their own that suits their application.

author: pinlee
author_rank: Newbie
timestamp: November 16, 2015, 06:26:50 am
content: First thing first, I am sorry to post in the wrong category. I should have this post in the Repair category.I can what looks like me two pieces of glasses glued together to make the screen. Is there ways to open and cleaning the darken spot? What cause it?

author: ataradov
author_rank: Super Contributor
timestamp: November 16, 2015, 06:30:37 am
content: Quote from: pinlee on November 16, 2015, 06:26:50 amThere is also liquid crystals between the glass plates. The crystals are distributed in a really thin uniform layer. The dark spot is those crystals leaking out because geometry of the plates was violated.There is absolutely no way to repair this. It is like trying to repair inner layers of 8-layer board. Simply can not be done.

author: all_repair
author_rank: Frequent Contributor
timestamp: November 16, 2015, 07:24:21 am
content: There is universal AC remote controller selling quite cheaply. It does work, I have bought few to replace the remote for my Dakin aircond.

author: rs20
author_rank: Super Contributor
timestamp: November 16, 2015, 07:42:54 am
content: Quote from: ataradov on November 16, 2015, 06:30:37 amIndeed; IIRC there are sometimes also tiny little glass spheres mixed in with the liquid crystal -- their purpose is to hold the glass plates apart at the intended spacing.

author: pinlee
author_rank: Newbie
timestamp: November 20, 2015, 10:15:33 am
content: I managed to find one universal remote from Taobao. It has the same design like my current old remote. I will try to use its screen to replace mine. Or, to use it directly.http://world.taobao.com/item/43571608111.htm?spm=a312a.7700825.1997196601.14.RezRAv
Darwin Electronic lab needed WORLD SOLAR CHALLENGE - Page 1
Forum section: electronics / beginners

author: Meche
author_rank: Newbie
timestamp: September 21, 2017, 12:21:02 pm
content: Hi!I am a part of a team in the world solar challenge and I wounder if there is someone out here in Darwin who is willing to lend lab equipment so that I could solder 4 PCB cards.We are very far from home so it is difficult to find where I can do this. If there is a warmharted person out there who could lend a hand I would appreciate it very much.Thanks in advance
Data and synchronization signals on the same wire? - Page 1
Forum section: electronics / beginners

author: m4rtin
author_rank: Regular Contributor
timestamp: August 13, 2015, 08:12:11 pm
content: I readNetwork Maintenance and Troubleshooting Guidebook and in paragraph where Ethernet frame preamble is explained, it says that except for 100BASE-T4, faster versions of Ethernet are synchronous. Is it possible to keep both data and synchronization signal on the same signal path?

author: retrolefty
author_rank: Super Contributor
timestamp: August 13, 2015, 08:39:00 pm
content: QuoteOf course, that is how synchronization links work, a clock is 'extracted' from the data stream with additional hardware both on the transmit end to 'ensert' the clock information and at receiver end to 'extract' the timing information. Note that many/most micros these days have USART hardware build in, so most of this all ready avalible. Check out a typical AVR datasheet for a description of the USART options.

author: m4rtin
author_rank: Regular Contributor
timestamp: August 13, 2015, 09:00:42 pm
content: Quote from: retrolefty on August 13, 2015, 08:39:00 pmI see, thanks! How is the clock signal differentiated from data signal? Is it with different voltage?

author: helius
author_rank: Super Contributor
timestamp: August 13, 2015, 09:07:09 pm
content: I think that is kind of a half-truth, all types of Ethernet are synchronous in the sense of not having start and stop bits. The only important difference between 100BASE-T4 and the rest is that it uses all four pairs of cat3 at a lower modulation rate than 100BASE-TX (which requires cat5 because of its higher bandwidth). The data signal is differentially driven over twisted pair, and is self-clocking. On lower speed links that is achieved with Manchester coding, which is a self-clocking code with a coding efficiency of 1:2, whereas on higher speed links like 1000BASE-T it is a code like 8b10 or 64b66 with much higher efficiency.The clock is extracted by having the sender and receiver both use an accurate reference frequency, sending a framing burst before each data packet, and a special PLL in the receiver that locks onto the frequency of the framing burst. Similar techniques are used everywhere, from CD-ROMs to wifi.
Data collector with Sp32, RS485 and RS-RA radiation transmitter,  - Page 1
Forum section: electronics / beginners

author: Stalyn
author_rank: Newbie
timestamp: May 28, 2025, 05:06:05 pm
content: Hi everyone, I'm looking for some help with a connection setup involving an ESP32, an RS485 module, and a solar radiation sensor. I'm trying to get proper communication between the components, but I'm running into some issues. If anyon

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: May 29, 2025, 10:37:59 am
content: Is there a schematic that you're following?
Data for TFT Screens - Page 1
Forum section: electronics / beginners

author: Robert.Adams
author_rank: Contributor
timestamp: April 26, 2014, 06:54:41 pm
content: Hello all,I'm trying to branch out into displays and mobile devices and I'm working on setting up a 400x240 TFT (Sharp Memory LCD). For writing the data to the display is there a way to compress the data from the 96000 pixels that are on a frame? It would be a drag to put a 512kB EEPROM and only get ~5 frames out of it.

author: hagster
author_rank: Frequent Contributor
timestamp: April 26, 2014, 08:03:01 pm
content: Its a 1bit display so you can store 8pixels in a byte. I make that 42 images in 512kb uncompressed.

author: mariush
author_rank: Super Contributor
timestamp: April 26, 2014, 08:19:49 pm
content: You can also do some sort of RLE compression on the image data, to shrink the images with minimal decompression time :http://en.wikipedia.org/wiki/Run-length_encodingDepending on the TFT screen and the controller driving it, you may also be able to send sprites (think of an icon or each letter in a font as a sprite) or update just regions of the screen, or upload bitmap fonts into the tft screen..

author: mariush
author_rank: Super Contributor
timestamp: April 27, 2014, 02:08:50 am
content: In case it's not clear, I meant uploading sprites and bitmap fonts in the internal memory of the tft controller and then just reference them (for example tell the controller to draw sprite 5 out of 40 loaded inside it at coordinates x,y).For a black and white display, jpeg compression is really too complex and unsuitable). If you're really keen on compressing stuff, look forRLE, LZ77, huffman,or other algorithms likehttps://hg.java.net/hg/solaris~on-src/file/tip/usr/src/uts/common/os/compress.chttp://oldhome.schmorp.de/marc/liblzf.htmlthat are relatively easy to port to microcontrollers
Data logging both current and voltage at same time with 1 DMM - Page 1
Forum section: electronics / beginners

author: Mattjd
author_rank: Regular Contributor
timestamp: February 15, 2019, 04:33:10 pm
content: Has anyone experimented with logging both voltage and current with a single DMM?Lets say I take my rigol dm3058e, I have it connected to matlab and have a bunch of drivers written that log measurements for me and display them on a graph in pretty close to real time.If I switch modes, between current and voltage really fast and capture a measurement. How well do you think this will work? I mean the dm3058e does have a dual display measurement, I just havent tried doing this on my computer yet.If anyone has ever tried it I would love to know. Or if there are alternatives I would love to know also.

author: malagas_on_fire
author_rank: Frequent Contributor
timestamp: February 15, 2019, 05:51:41 pm
content: Have you seen this video?Checkout the code in the comments , they are measuring Voltage and Resistance, so it's a matter of trying out

author: Mattjd
author_rank: Regular Contributor
timestamp: February 15, 2019, 09:23:39 pm
content: I had not seen that. I was just thinking if you would be able to sample each signal fast enough to be able to adequately log them both
Data Loss During Micro Controller Data Logging - Page 1
Forum section: electronics / beginners

author: gregolive
author_rank: Newbie
timestamp: January 21, 2018, 05:10:51 pm
content: Hello,I am using a micro controller to record data from some accelerometers and am currently trying to do a quick test to ensure the data logging is working. I had the accelerometers and micro controller (Teensy 3.6) plugged into a breadboard and recorded some data while I shook the accelerometers around. My concern is that there seems to be some data loss (see attached image) during the logging, where the recorded bit value drops to close to zero and I am not sure what the cause is. Is this common for data logging at high speeds or maybe it has to do with shaking sensors that are just plugged into a breadboard? One other thing is that the ADC reference voltage on the Teensy 3.6 is 1.2V and I was using the 3.3V source on the Teensy 3.6 to power the accelerometers (this will be fixed later, I just wanted to do a quick test of the data logging) so I'm not sure if that could be the cause? Any help would be greatly appreciated! Thanks in advance!

author: phil from seattle
author_rank: Super Contributor
timestamp: January 21, 2018, 06:11:50 pm
content: Quote from: gregolive on January 21, 2018, 05:10:51 pmSee the highlighted text. That's the first thing I'd consider. There really is no substitute for a really good mechanical connection like solder or screw terminals. Breadboards don't give you that. however, it's also possible that your shaking is generating the actual values so don't 100% rule it out.

author: Nusa
author_rank: Super Contributor
timestamp: January 21, 2018, 06:31:02 pm
content: Whats the pattern if you DON'T shake the sensors? That should answer the question of whether the spikes are from the sensor activity or something else.

author: gregolive
author_rank: Newbie
timestamp: January 21, 2018, 08:44:17 pm
content: Thanks for the replies! Turns out it is from me shaking the sensors, I tired running it with the sensors sitting there and there were no issues!
Data needed for YC2202 point contact Germanium diodes - Page 1
Forum section: electronics / beginners

author: CJay
author_rank: Super Contributor
timestamp: February 14, 2017, 05:05:15 pm
content: I've got a bag of YC2202 diodes, glass encapsulated point contact germanium diodes and I could do with a datasheet for them, I think they're ex MOD/Armed forces stock but I can't find any reference anywhere, can you help?
Data Precision 6100 - What does it measure? Not much info on Waveform Analyzer - Page 1
Forum section: electronics / beginners

author: cecilini
author_rank: Newbie
timestamp: January 10, 2022, 09:50:02 am
content: I have searched the internet on the Data Precision 6100 and it says it is a waveform analyzer. Some sites say it is a signal analyzer. There is no youtube on wave analyzers and a search of what is a waveform analyzer, takes you to signal analyzers. I also found the manuals that were uploaded by a member but it was too complicated for me. I need to know what it measures and how the Data Precision 6100 works. I know it is obsolete equipment and the company does not exist.

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: January 10, 2022, 10:20:08 am
content: Broadly speaking, a waveform analyzer is(was) a special type of oscilloscope with a strong focus on the most accurate reproduction of the waveform that is possible. This usually comes with drawbacks such as less possibilities in triggering, less memory depth & reduced input voltage.They are generally aimed at engineers that work on transmission systems where the quality of the modulation (QAM for example) is of importance.If you are looking to buy an oscilloscope for beginner purposes, you arefar better offwith an entry level Siglent /Rigol/Uni-T, they will all blow that DP6100 unit out of the water and come complete with probes. Waveform analyzers will typically have 16 or 24 bit bit resolution (vs. 8 or 10 bit on a entry-level scope). Obviously this eats much more memory, driving up the cost and CPU requirements.That said, high end scopes have made waveform analyzers obsolete. Technology has advanced to the point where it is no longer necessary to make compromises to achieve high reproduction quality, so they are mostly a thing of the past.
Data sheets - Page 1
Forum section: electronics / beginners

author: Auggie
author_rank: Contributor
timestamp: February 15, 2010, 09:36:43 pm
content: Hello everyone, I have a question about data sheets. When looking up a data sheet for a PCB board for example what should you be looking for? There are all kinds of numbers and serial numbers. How do you know which ones are part numbers and which are numbers for other things?

author: DJPhil
author_rank: Frequent Contributor
timestamp: February 15, 2010, 10:29:48 pm
content: I'm not sure what you mean by pcb board.Do you mean, say, looking for drivers for an old PC card?Were you perhaps instead speaking of parts themselves, like looking up chips or transistors?I've done a lot of both salvaging stuff, and both are trial and error. It's something experience helps with, you start to remember particular combinations of letters and numbers.Could you give a few examples of what you mean, or maybe if you've got something specific in mind?

author: desolatordan
author_rank: Regular Contributor
timestamp: February 16, 2010, 06:21:26 am
content: Sometimes it's impossible to identify parts just by the house markings on the IC package.Finding a logo on it to identify the company, then start searching for any alphanumeric code on the IC.And if you're trying to find info on an actual PCB based on a serial number printed on it, good luck...

author: Simon
author_rank: Unknown
timestamp: February 26, 2010, 09:35:09 pm
content: if you need a datasheet for a part just google the part number followed by "datasheet" invariably you will be taken to a datasheet search service that will have many versions of it. if you have a board and need to know that it does you have less of a chance but again google is your friend as someone else may have put up information about the board if they used it for something
Data transfer communication - Page 1
Forum section: electronics / beginners

author: amangg
author_rank: Newbie
timestamp: April 28, 2017, 10:21:39 am
content: Hello everyone,I am new to the world of electronic design. I have been working on projects to use multiple sensors . I am intrigued by how the data is transferred from the sensor to a microcontroller mainly through SPI and I2C protocols. I have also seen a few breakout boards that enable that communication.What I would like to learn more about is how to convert the data from sensors to an I2C/SPI protocol ? How to decide ? or how are those breakout boards designed ? What kind of factors does it depend on? analog /digital outputs?Any references on study material will also be great as I would like to go in-depth in understanding the communication between sensors and microcontrollers, devices

author: Benta
author_rank: Super Contributor
timestamp: April 28, 2017, 10:54:59 am
content: A lot of sensor ICs available today already have SPI or I2C built in.

author: amangg
author_rank: Newbie
timestamp: April 28, 2017, 11:01:52 am
content: Quote from: Benta on April 28, 2017, 10:54:59 amYes they do. But for some independent sensors such as MQ-6 (gas sensors in general), they need to have external breakout. Moreover, I wish to learn more about how to design a data transfer mechanism for such sensors.

author: jeroen79
author_rank: Frequent Contributor
timestamp: April 28, 2017, 11:40:24 am
content: It depends on what kind of output the sensor has.If it has a voltage output then you can use aDACADC with SPI/I2C interface.

author: FreddyVictor
author_rank: Regular Contributor
timestamp: April 28, 2017, 11:41:52 am
content: Quote from: amangg on April 28, 2017, 11:01:52 amThe MQ-6 is an analog sensor in that it outputs a variable voltage depending on reading.In its simplest form, to create a digital board to use like other digital sensors, add a microcontroller to measure the sensor voltage (ADC input) and then run i2c in Slave mode (or SPI) to respond to requestswhat i2c device address & registers (data + config) you use is up to you
Datasheet app - Page 1
Forum section: electronics / beginners

author: Chopsticks
author_rank: Regular Contributor
timestamp: January 29, 2014, 12:00:56 pm
content: I'm not to sure if I'm in the right area for this but I was wondering if anyone could recommend a good ipad app for storing all my datasheets so I can take them on the go. I don't mind paying for the app as this is a really useful thing for me as I move around with my projects a lotThanks guys

author: Unknown
author_rank: Unknown
timestamp: January 29, 2014, 01:10:58 pm
content: Quote from: Chopsticks on January 29, 2014, 12:00:56 pmHow 'bout a using a reference / citation manager (e.g. EndNote, Mendeley, Zotero, etc)? Definitely overkill, but they usually have better organisational/searching/annotation features when compared to PDF managers like GoodReader / GoodNotes, etc.(Personally I use a Mac program called Sente on my Mac & iDevices, but any of the others should do as well...)

author: Unknown
author_rank: Unknown
timestamp: January 29, 2014, 02:06:35 pm
content: On the PC I stuff them onto Google-drive / Dropbox then open them on the iPad and organise them to the "PDF Reader" reader app.

author: Chopsticks
author_rank: Regular Contributor
timestamp: January 30, 2014, 06:42:21 am
content: Tac I'll take a look at endnote etcI haven't really though about using something on my mac, currently it's just a big mess of a folderI could import into the iBooks "PDF reader' but the problem is it isn't really good at search, meta data and so forth, I with there was a good mac and ipad app that has cross referencing built in... I can dream

author: cellularmitosis
author_rank: Unknown
timestamp: January 30, 2014, 07:10:03 am
content: I use Dropbox to keep my data sheets synced between my Mac, PC, and iPhone. Free and simple.A paid Evernote account would search the contents of the PDFs.

author: jeremy
author_rank: Super Contributor
timestamp: January 30, 2014, 07:50:40 am
content: I use GoodReader and Google Drive

author: jbrewton
author_rank: Newbie
timestamp: January 30, 2014, 09:11:13 pm
content: What about using the Octopart App to just look at them when you want.
Datasheet cicuit explanation - Page 1
Forum section: electronics / beginners

author: HeyTom
author_rank: Contributor
timestamp: February 17, 2014, 08:12:06 pm
content: I found this in the lt1031 (precision 10v reference) datasheet, but I don't quite get it.How do you calculate the addition of the 8.2 ohm resistor and the LED gives a 100ma current limit vs. the other unlimited version on the same page? Thanks.

author: hamster_nz
author_rank: Super Contributor
timestamp: February 17, 2014, 09:38:58 pm
content: It looks as though it is trying to limit the current through the 'IN' pin on LT1031 to around 3ma. Once that is reached, the 2N2905 is slowly switched on allowing some of the the current to bypass the LT1031.The forward voltage of the LED limits the maximum base voltage on the 2N2905 to about V+ - 2.3V, which in turn limits the maximum voltage over the 8.2 ohm R to 1.7V.So it looks to me that it should current limit at about 200mA (1.7V / 8.2 Ohm).
Datasheet Confusion - Page 1
Forum section: electronics / beginners

author: tim_d
author_rank: Newbie
timestamp: January 01, 2012, 01:07:51 pm
content: Hi All,After a little help. I'm looking at the datasheet for a trim resistor and am trying to make an eagle part for it. The lead diameter is marked down as 3-0.5+-0.1mm, with an overall tolerance for the entire diagram of +-0.3mm. I'm slightly confused by the notation here with the 3-0.5 bit.Anybody able to shed some light on exactly what it means?Thanks,Tim

author: 8086
author_rank: Super Contributor
timestamp: January 01, 2012, 01:53:40 pm
content: A link to the datasheet in question would help

author: olsenn
author_rank: Frequent Contributor
timestamp: January 01, 2012, 03:05:25 pm
content: Stuff like this I always get out my trusty ruler and make the measurments myself

author: gxti
author_rank: Frequent Contributor
timestamp: January 01, 2012, 05:46:36 pm
content: Sounds like it's saying "0.5mm, in 3 places". I'm guessing it's referring to the diameter of the legs.

author: tim_d
author_rank: Newbie
timestamp: January 01, 2012, 07:01:52 pm
content: Quote from: gxti on January 01, 2012, 05:46:36 pmGah! Should have been obvious it meant 3 off 0.5mm really. Thanks.
Datasheet for CP Clare Type 26 stepping switch? - Page 1
Forum section: electronics / beginners

author: Dave92F1
author_rank: Contributor
timestamp: October 11, 2024, 02:36:52 pm
content: I don't know if this is the right place to ask, but I picked up one of these on eBay (NOS, $75 shipped, 24x8) and am looking for a datasheet for it. Anybody know where I can find one? It's a work of art.

author: Bryn
author_rank: Regular Contributor
timestamp: October 11, 2024, 03:25:08 pm
content: Unfortunately, no datasheet for it is available online... you may need to check to see if the manufacturer have it on their site, or contact them about it.
Datasheet for Obscure Part - Page 1
Forum section: electronics / beginners

author: Ketema
author_rank: Newbie
timestamp: August 19, 2013, 11:48:55 pm
content: Hello guys hope you all are great! My first post so please be gentle with me. I was hoping if you guys know what this part is. I scoured the net for a datasheet but I came up empty handed. Thank you for your help in advance!

author: free_electron
author_rank: Super Contributor
timestamp: August 20, 2013, 12:38:43 am
content: NEW ENGLAND SEMICONDUCTOR (NES)a high reliability bipolar transistor. type 18876 you'll need a mil-spec x-ref list to find what it is. most likely from some avionics stuff. probably germanium. it's old ...

author: edavid
author_rank: Super Contributor
timestamp: August 20, 2013, 01:16:08 am
content: Quote from: free_electron on August 20, 2013, 12:38:43 amIf it's from 1990, probably not germanium.