hybridfree/eevblog-posts huggingface dataset:
DAC function generator filtering - Page 1
Forum section: electronics / projects

author: Jon86
author_rank: Frequent Contributor
timestamp: August 24, 2020, 01:49:14 pm
content: I'm thinking about designing a simple low-frequency AWG for audio work, but I'm struggling to understand what I've read about output filtering when using a DAC to generate waveforms.If I generate a 20KHz sine wave with a 200KHz sample rate, I know I could have a sharp rolloff reconstruction filter above 20KHz that would remove almost all of the stepping distortion created by the DAC, but if I then want to generate say, 20Hz, how do I remove these steps using the same filter? Depending on the bit depth used, won't the samples take place at different intervals, and produce different frequencies in the output?I guess another question would be how important is it for general purposes to actually filter this output? Would a simple RC filter with a -3dB at 1/2 the sampling frequency suffice? Especially if I'm using a 24bit DAC anyway.Hopefully someone has done this before and has some insight, apologies if this has been discussed here already.

author: tszaboo
author_rank: Super Contributor
timestamp: August 24, 2020, 02:29:22 pm
content: What kind of DAC are you using? Is it a delta-sigma? The output of that doesnt look anything like the steps. It looks like a PWM signal.And no, a simple -3db rc filter is not suitable, there should be several order filtering.

author: Kleinstein
author_rank: Super Contributor
timestamp: August 24, 2020, 02:39:12 pm
content: The filter is there mainly to remove the signal beyond the Nyquist limit. So with 200 kSPS from the DAC this would be the signal beyond 100 kHz. So it is the sampling frequency and not the signal frequency that set the limit. So the filter can be fixed at some 30-70 kHz, depending on how steep. The steeper the filter the high one could go for a given sampling rate.The usual way with DSS generators is to have a sampling frequency of some 50 MHz or higher and than a higher order (e.g. 7 th order) elliptical filter, that is a low pass combined with some extra notches just in the stop band. With such a steep filter one could use up to about 1/4 to 1/3 the sampling frequency. For the high frequencies one can use a passive LC filter for this. However the inductors may get bulky much below 1 MHz.A 24 bit DAC would be a sigma delta DAC and would thus already include some filtering / oversampling. The filter needs would be different from a normal DAC and there should be some info from the DAC used.

author: MarkF
author_rank: Super Contributor
timestamp: August 24, 2020, 03:30:26 pm
content: I found this online LC filter program very useful in designing a filter:https://www-users.cs.york.ac.uk/~fisher/lcfilter/Just enter the filter order, frequency, configuration and impedance to get the needed component values.
DAC input to IQ modulator - Page 1
Forum section: electronics / projects

author: srscricket
author_rank: Newbie
timestamp: February 05, 2014, 07:25:26 am
content: I have two differential outputs from a dac that needs to go in to the four pins of the IQ modulator. I was trying to avoid going to another layer and it seems I cant. I was wondering if anyone had any ideas on separating them in to layers. The picture is what I have so far.

author: Rerouter
author_rank: Super Contributor
timestamp: February 05, 2014, 07:31:10 am
content: you haven't said what your grid size is, but i would guess using a 1206 package resistor as a jumper if you want to avoid going interrupting the other layer (a zoomed out image would equally be nice)

author: srscricket
author_rank: Newbie
timestamp: February 05, 2014, 07:45:32 am
content: The grid size is 20 mil. The picture was zoomed in because that was all I had down, most of the other pins will be the outputs from an fpga. Thanks for the reply.-edit- now with attachment

author: fcb
author_rank: Super Contributor
timestamp: February 05, 2014, 12:00:37 pm
content: It won't matter a jot if it's low frequency, but will if it's high frequency. You should give a bit more information about the IC's and the frequency.There maybe other options (perhaps their are other DAC outputs available, perhaps you can flip a bit in the DAC configuration and sort out polarity, etc..).All else being equal, you need to make sure the traces are the same length and have the same characteristic impedance (so each trace has the same number of vias etc...).

author: w2aew
author_rank: Super Contributor
timestamp: February 06, 2014, 03:04:13 am
content: Quote from: fcb on February 05, 2014, 12:00:37 pmCan you invert the data on I or Q in the DAC, thus being able to swap the diff pairs? Maybe that will help your layout.
DAC minimum reference voltage? is it just a guide line? why???? - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: November 09, 2013, 04:06:02 pm
content: Why do DAC chips have a minimum reference voltage?I have a DAC that I like in mind but it says the minimum reference voltage is 1V. Why won't it work with say 100mV reference? Why do DACs have a minimum reference voltage requirement? My understanding of their operations (built a discrete DAC once) tells me that they should not have this requirement.

author: qno
author_rank: Frequent Contributor
timestamp: November 09, 2013, 05:15:00 pm
content: Maybe look at the noise figures.Below a 1V reference the LSB is lower than the noise.

author: SArepairman
author_rank: Frequent Contributor
timestamp: November 09, 2013, 05:35:26 pm
content: if thats the case then I am fine.A moving noise band is just fine with me.I also read there might be gain errors if the minimum voltage is lower then the specification.Is there anything else to watch out for?

author: qno
author_rank: Frequent Contributor
timestamp: November 09, 2013, 06:10:31 pm
content: I guess not.I one used a DAC as an attenuator.Put an biassed AC voltage on the reference and select the amplitude with the DAC.It woked fine, only lower output levels sufferd S/N distortion.

author: madires
author_rank: Super Contributor
timestamp: November 09, 2013, 10:21:27 pm
content: Resolution and accuracy. Based on the design of the DAC it might not support such small steps.

author: SArepairman
author_rank: Frequent Contributor
timestamp: November 10, 2013, 01:43:00 am
content: Quote from: madires on November 09, 2013, 10:21:27 pmcan you elaborate?

author: SeanB
author_rank: Super Contributor
timestamp: November 10, 2013, 08:49:05 am
content: Some use the reference to drive transistors ( or FETs) switched inside the unit, and below the minimum level they do not turn fully on ( or off) enough to operate properly, giving rise to either a varying offset voltage and spurious outputs. To use a DAC with low voltage you need one with either a 4 quadrant reference input or one designed to be used as a variable attenuator.Otherwise use a level above the minimum and divide the output down to the desired level using a buffer opamp and a resistive divider, or a fractional gain opamp circuit.
DAC with a true zero output? - Page 1
Forum section: electronics / projects

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 09, 2018, 08:50:30 pm
content: Does that exist? A DAC that will just output 0V (or disconnect the output) at a 0 code value? Or is this something that I have to work around?

author: tszaboo
author_rank: Super Contributor
timestamp: May 09, 2018, 09:03:17 pm
content: You could connect the GND of the DAC to (say) -150mV, level shift the output, divide it down with two resistors to a negative voltage... Or live with that 1mV offset.

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 09, 2018, 09:13:37 pm
content: how would you level shift the output with just a single supply?I can see level shifting it up, but how would you level shift it in the reverse direction?

author: ogden
author_rank: Super Contributor
timestamp: May 09, 2018, 09:37:07 pm
content: Quote from: Gibson486 on May 09, 2018, 09:13:37 pmYou can level shift using "level shifting supply", likeLM7705Oh, and there is DAC with true zero output, it's PWM DAC.

author: tszaboo
author_rank: Super Contributor
timestamp: May 09, 2018, 10:19:07 pm
content: Quote from: Gibson486 on May 09, 2018, 09:13:37 pmIf you have a single supply, nothing is going to be 0V, because any small current will create voltage drops.

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 09, 2018, 10:30:42 pm
content: You may take a look at rail-to-rail output DACs such as the DAC7512.You will still get an offset voltage of a few mV at zero-code. But this DAC has a power-down mode that can get its output in hi-Z or connected to GND via a 1k or 100k internal resistor, so if you don't need a very fast sample rate, this should do it. Just put it in shutdown mode for the zero code.

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 10, 2018, 02:16:21 pm
content: Quote from: SiliconWizard on May 09, 2018, 10:30:42 pmNice....the dac I am using has that and I completely ignored it! Thanks!

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 10, 2018, 02:17:52 pm
content: Quote from: ogden on May 09, 2018, 09:37:07 pmNice...never knew about that chip...nice to add to my bag of tricks.

author: CopperCone
author_rank: Super Contributor
timestamp: May 10, 2018, 03:57:56 pm
content: Unless your pwming with a relay and dont care about thermals you will still have a offset. It depends on the driver stage but when using active dividers all your doing when pulling low is making a very good voltage divider.
DAC0808 circuit parameters - Page 1
Forum section: electronics / projects

author: miketan3904
author_rank: Contributor
timestamp: November 18, 2021, 01:40:15 pm
content: Hi. I wanted to use DAC0808 for my project but I couldn't find any resources on how to choose the value for the voltages and resistors value. There is a circuit being provided in the page 4 of the datasheet and I followed all the settings in the datasheet except I used LM358N to replace the op amp in the schematic diagram. I have a few questions below:1. Does anyone knows if the -15V at the VEE is compulsory and could it be some other voltage?2. When I use the setting in the circuit, I only get half of the expected output voltage. For example, I only get 5V when I expect 10V at the output. Does anyone know the reason for this?Datasheet:https://www.ti.com/lit/ds/symlink/dac0808.pdf?ts=1637242773375

author: CaptDon
author_rank: Super Contributor
timestamp: November 18, 2021, 04:17:18 pm
content: I think the National Semiconductor original data book had some excellent info and diagrams. I used the DAC0808's all the time and had great luck with them. I am currently using a pair to generate sine/cosine signals to form circular traces on a radar system. I generated the truth tables by hand but also found an online calculator where you program the number of bits and number of steps and it will generate the binary truth table for you. The book explains the scaling, offset from zero if desired, and overall gain. If I remember, the 0808 is designed as a variable current source, not a variable voltage source, so some external circuitry will convert the current output to voltage output, thereby requiring the opamp you mentioned with inverting feedback to set gain.

author: miketan3904
author_rank: Contributor
timestamp: November 23, 2021, 04:40:01 am
content: From your experience of using it, have you tried to use other value of VEE like connecting it to ground? I was trying to modify the circuit without affecting the operation too much so that I can easily use the power supply that I have.
DAC0808 Single power supply - Page 1
Forum section: electronics / projects

author: diegobarriga
author_rank: Newbie
timestamp: January 07, 2017, 03:38:44 am
content: Hello All,I'd appreciate your help with an issueI found this app note that explains how to run DAC0808 with only one power supply (avoiding the use of -15VDC),Has anyone tested this circuit before? ¿What modifications should I do to have an 0-12V output instead of 0-5V shown in the schematic? or ¿How do I calculate these modifications?Thanks in advance for sharing your knoledge and kind support

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: January 08, 2017, 02:42:54 pm
content: Oh really you are using that old DAC....I recommend using some new DACs

author: danadak
author_rank: Super Contributor
timestamp: January 09, 2017, 12:23:49 pm
content: You an get DACs with onboard reference, and onboard output amp.You can even get them on a UP with all the above, Cypress PSOC.For me what stands out is -1) Routability2) Fast 12 bit SAR A/D and slow 20 bit DelSig3) DFB (Digital Filter Block) that is dual channel, handle FIR or IIR filters, or DFBcan be used as a GP fast processor block, similar to RISC block4) MSI logic elements GUI based and/or the UDB Verilog capability. Eg. the FPGAlike capability5) Onboard Vref6) IDAC, VDAC, OpAmps (up to 4), comparator, mixer, switch cap, analog mux....7) LCD, COM, UART, I2C, I2S, One Wire, SPI, Parallel, LIN, CAN, BLE, USB9) Custom components capability, create with schematic capture or Verilog10) DMA to offload processes like filters, COM, Display11) ARM M0 (PSOC 4) or M3 (PSOC 5LP) or 8051 core(PSOC 3)12) Extensive clock generation capabilities13) All components supported by extensive prewritten APIshttps://www.element14.com/community/thread/23736/l/100-projects-in-100-days?displayFullThread=truehttp://www.cypress.com/documentation/code-examples/psoc-345-code-examplesGreat video libraryAttached component list. A component is an on chip HW resource.Free GUI design tool with schematic capture, "Creator". Components have rich API library attachedto each component. Compilers free as well.PSOC 4 is low end of family, consider 5LP parts as well. PSOC 4 also has arduino footprint boards (pioneer) as wellhttps://www.elektormagazine.com/labs/robot-build-with-cypress-psochttp://www.cypress.com/products/32-bit-arm-cortex-m-psocRegards, Dana.

author: diegobarriga
author_rank: Newbie
timestamp: January 09, 2017, 10:09:32 pm
content: DAC0808 is old but it is what electronics store have available in my city
Daewoo DVR-G892 VCR Jog-Shuttle Control - Page 1
Forum section: electronics / projects

author: German_EE
author_rank: Super Contributor
timestamp: April 21, 2015, 05:14:21 pm
content: My young apprentice and I have just had ninety minutes fun doing a destructive teardown on a Daewoo VCR. The jog-shuttle control looks too good to waste but I have no idea of the pinout. Does anyone have access to the service manual so I can find out the connections?

author: dom0
author_rank: Super Contributor
timestamp: April 21, 2015, 05:56:32 pm
content: If it has few pins (six-seven or so) the jog-ring-thingy is a pot and the shuttle is a normal quadrature encoder. There are also "pure digital" ones with a few more pins where the shuttle is a quadrature encoder and the jog-ring-thingy is a grey coder.

author: German_EE
author_rank: Super Contributor
timestamp: April 21, 2015, 06:30:21 pm
content: There are five pins on the control and this is expanded to eleven connections going out of the PCB (although some of these are assigned to buttons). The only semiconductors on the PCB are diodes and there are no electrolytic capacitors to aid in power supply identification

author: dom0
author_rank: Super Contributor
timestamp: April 21, 2015, 06:35:20 pm
content: Five pins ... maybe GND is shared between the rotary encoder and the ring-thingy pot?

author: SeanB
author_rank: Super Contributor
timestamp: April 21, 2015, 06:58:48 pm
content: You have the jog with the play and stop buttons in it? If so then they are using a resistive matrix, with the play and stop keys in the one matrix, and the jog will have a set of matrix switches that control the various forward and reverse speeds in discrete blocks, with a spring centring the knob.If you have the model number that will help in getting the manual.

author: German_EE
author_rank: Super Contributor
timestamp: April 21, 2015, 07:31:37 pm
content: Further investigation (this is much more fun than German TV)Pin 7 is the common pin on the PCB and leads to pin 4 on the encoder.Pins 1,2,3 and 5 on the encoder are all connected to the anodes of diodes that eventually lead to pins 8-11 on the output. I think this thing may be just switches rather than a rotary potentiometer

author: SeanB
author_rank: Super Contributor
timestamp: April 21, 2015, 08:05:34 pm
content: Almost anything is more interesting than TV....... So you have a rotary encoder with either an inner ring that you rotate around, and an outer which is centred, and has a switch to say if the outer ring is being held forward or reverse. Inner ring will be a standard quadrature encoder unit and the outer will be 2 switches then.

author: dom0
author_rank: Super Contributor
timestamp: April 21, 2015, 10:06:59 pm
content: That's interesting. I salvaged one from a video editor console and two from mazen (essentially studio / high end VCRs), they had a pot or a grey-coder for the outer ring thingy. Maybe this one here is more like a lower end variant of a jog/shuttle?
Daisy chain power supply design - Page 1
Forum section: electronics / projects

author: Garn3
author_rank: Newbie
timestamp: November 12, 2018, 08:28:59 am
content: Hello everyone,I need your help on design a « power supply ».Context : We are working on a product that we might sell one day : a grow light. We want to be able to daisy chain them and in order to reduce the weight and the cost, I want to « put out » the heavy and costly stuff.Basically put the transformer outside the devices. The transformer circuit will deliver 48V AC and up to 20A. One main grow light will be connected on it. And another power supply circuit in this grow light will make that 48V AC into 48V DC regulated and be able to deliver up to 2A. And another grow light can be connected on that one (but it will take the power directly from the main source) etc etc.But I dont know if what I am trying to do is possible and really cheaper and practical.Please look at the attachements for more information. And please let me know what you think about it.If you have any question, please feel free to ask. Thank you for your help.Niels(Sorry for my english)

author: Cliff Matthews
author_rank: Unknown
timestamp: November 12, 2018, 10:36:18 pm
content: Welcome, FWIW this would have been better posted in the beginners section.1200VA Transformers are NOT cheap commodity items. They are costly, heavy, and kind of prehistoric for this application. Also, doing chaining this way forces you into using 20+ ampere (thick, costly no so flexible) cable and chaining connectors. Since environment specified can be prone to humidity, try using sealed fan-less units such as theMean Well HEP-100 or HEP-150

author: ejeffrey
author_rank: Super Contributor
timestamp: November 12, 2018, 10:53:25 pm
content: I agree that using a 230 V to 48 VDC/2A power supply on each module likely the best option. There is no reason to use 48 VAC distribution here that I can see. If you really needed to keep the power supply away from the grow lamps use a huge 48 VDC power supply. You will still be stuck with thick expensive cables and connectors, but then there will really be almost no electronics inside the modules.
Daisy chaine of 15 TLC5940 connected to µC - Page 1
Forum section: electronics / projects

author: Rompel
author_rank: Newbie
timestamp: October 05, 2020, 08:14:25 am
content: I developed a HW based on TLC5940 which is connected to a µC. It was since Friday on permanent test and it works whitout any problem.The signal level was also ok on friday.As from today morning, out of 27 boards, 3 are not working any more. By troubleshooting through measurement, I measure the signal on each pin and the level from µC was not more 3,4V but 3,7V. Also the SCLK pin from µC is not toggling anymore as you can see on the picture (Yellow is the input voltage 24V which is step down to 5V and 3,4V, blue is the Blank signal at aroung 3,7V and SCLK signal toggling between 0V and 700mV)The sclk signal is trying to tggole but not up to 3,4V or 3,7V.What could be the cause of this issue?Furthermore some LED on the board are not more controllable, meaning the outn of the TLC9540 is always and the LED are getting extemly hell. This LED are always on when some other are off=> of course my LED driver (TLC5940) is defect, since changing the driver, averything work as usual.What could be the cause?What be delighted for any advice to find the cause.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 05, 2020, 09:11:54 am
content: English forum pleaseTranslatedI have a HW based on TLC5940 that is directly connected to the controlleris connected, in the endurance test since Friday.It had worked all day on Friday and everyoneSignal level (blue) was already correct. Yellow is my power supply,which is reduced to 5V and 3.4V.Today I find that it no longer works. I havetries to find the error. It turned out that my SCLK is no longerworks sees picture.It tries to switch through, but it only stays at around 700mV3.4V. The level of my signal is currently around 3.7V instead of 3.4Vthan it was on Friday.On a second driver, the Outn outputs are no longercontrollable and draw high currents (LEDs are extremely bright and extremely hot,when I switch on).What could be the cause of this?

author: Rompel
author_rank: Newbie
timestamp: October 05, 2020, 09:28:39 am
content: sorry and thanks for the translation
Daisy chaining clock generator chips - Page 1
Forum section: electronics / projects

author: TomS_
author_rank: Frequent Contributor
timestamp: July 29, 2022, 04:51:58 pm
content: Hi all,I am looking at using a couple of AV9154A-04 clock generator chips in a project to generate a multitude of different frequencies needed for a few different components. Two of these chips will allow me to generate all of the required frequencies (CPU, timers, ethernet, CPLD clock) while also providing an ability to modify the clock towards the CPU itself to support different speed grades/overclocking (bonus feature).Ive looked at a few different clock generators before coming across this one, and some of the others seem to support daisy chaining the 14.318MHz reference output from chip to chip - or at least they support the X1 pin being driven by an external oscillator rather than a crystal.The datasheet for the AV9154 does not seem to indicate this is "supported" anywhere, but I am wondering whether it would still work anyway?Thanks!Datasheet:https://pdf1.alldatasheet.com/datasheet-pdf/view/65389/ICST/AV9154A-04CS16.html
Daisy chaining hall effect sensors - Page 1
Forum section: electronics / projects

author: okw
author_rank: Frequent Contributor
timestamp: April 15, 2024, 07:02:00 pm
content: I'm daisy chaining a row of hall effect sensors. At the moment 27 sensors spaced out on a 130mm length (but I could loose or add a few sensors to make use of all inputs on an existing IC).I would like to see more than a 0 or 1 from the exact sensor where the magnet is. So if the magnet is between two sensors I would like an analoge value from all surrounding sensors, so I can calculate position with high resolution.I was thinking about a multiplexer, like 4067. Will this be a good choice, or are there better MUX alternatives, or even better techniques?What frequency with reliable position can I expect from this setup?
Daisy chaining of DC electonic load modules - Page 1
Forum section: electronics / projects

author: void_error
author_rank: Frequent Contributor
timestamp: July 03, 2015, 01:17:07 pm
content: These are the module connections:+12V (DC in for powering the control circutry)GND/-DUT (DUT = Device Under Test)+DUTSDA&SCL(temperature sensors)REF (for setting the current)What's the best way to connect the modules?

author: void_error
author_rank: Frequent Contributor
timestamp: July 04, 2015, 10:55:17 am
content: I'm thinking of using screws with links made out of small PCBs for the high current part and pin headers for the low current connections. Will I have any issues with ground bounce for pulsed load currents?
“Dallas 1-wire” - Page 1
Forum section: electronics / projects

author: david farid
author_rank: Newbie
timestamp: March 18, 2020, 02:23:47 pm
content: Helloi'm David we talked on the YouTube channel on the below linki've been trying to communicate with ds18b20i make the reset pulse and i had the presence pulseafter that i try to send 0x33 command read rom command but i didn't receive any reply i have no idea whyattached is my code in c language txt filealso is a pic on the scopei wish this info is enough

author: Ccandrews
author_rank: Contributor
timestamp: March 18, 2020, 04:11:36 pm
content: Can you post the waveforms from your scope please. Also, it is useful to take another output line from the processor and write a short pulse to it when you are reading the 1wire bus then watch this on the logic analyzer. Problems like this are often due to timing and you can only know when things are happening. Write an output pulse like in these videos so you know for sure. I will look this over to see if I see anything. Obviously you have tried a different chip in case this one is bad?Wait..What is this in your code?CyDelayUs(1u);//due to contect switching timeAre you using something mechanical in this?Finally, a logic analyzer is worth its cost when doing these sorts of projects.Craig

author: Andy Watson
author_rank: Super Contributor
timestamp: March 18, 2020, 04:46:08 pm
content: Quote from: david farid on March 18, 2020, 02:23:47 pmThere is no reply because you are not reading the device - you have to read the data back by initiating each bit-read with a short strobe pulse - 1us IIRC.I

author: Ccandrews
author_rank: Contributor
timestamp: March 18, 2020, 11:01:50 pm
content: Good catch. Presuming that the end of the code posted is the end of the code, I think you got it.

author: james_s
author_rank: Super Contributor
timestamp: March 18, 2020, 11:42:49 pm
content: A shortcut for figuring out this sort of thing, pick up one of the $3 arduino clones and get it running with that, this sort of part is well supported making it very easy to get it working.Once you have it working on that, scope the signals and see what it is doing that you are not. I find it very helpful to have a working baseline like this from which to compare.
Dallas DS1225Y FRAM conversions - Page 1
Forum section: electronics / projects

author: pinball!
author_rank: Newbie
timestamp: December 28, 2024, 12:05:01 am
content: I'm working on replacing a DS1225Y with an FRAM module on an arcade game. I see they make drop in replacement FRAM adapters to replace the NV SRAM. How are these modules getting around the CE difference between FRAM and SRAM? It would seem to me that it's only possible if by some miracle the CE is so sparsely used. By barely utilizing it, it may enable the CE line to fully reach a logic high between addressing? Or is there some sort of modification that doesn't entirely require reworking the memory controller?Wanted to see what considerations needed to be had when doing this sort of thing.

author: Miti
author_rank: Super Contributor
timestamp: December 28, 2024, 01:18:39 am
content: Some FRAMs are drop in replacement. Look at FM22L16. Also few simple gates can deal with that, see here:http://wolfalex.bplaced.net/te/hp3478a/fram/hp3478a_fram.htm

author: squadchannel
author_rank: Frequent Contributor
timestamp: December 28, 2024, 01:35:19 am
content: FM16/FM18 have that problem, but it fixed problem in FM28V.i am using FM28V.

author: pinball!
author_rank: Newbie
timestamp: December 28, 2024, 04:10:21 am
content: Good to know with the drop ins, I hadn't seen them. I'll have to take a look with a logic analyzer to see what I can get away with. I've seen the FM16s as a direct replacement for SRAM without addressing CE, need to look at how that's being done
Dallas DS1820 temperature sensors - Page 1
Forum section: electronics / projects

author: dan20n
author_rank: Newbie
timestamp: July 30, 2013, 01:56:04 pm
content: Hi guys and gals - long time YT subscriber of Dave, first time posting to this forum as I need some technical help. Ill try keep this simple and the obligatory apologies if this has been raised before.FYI:1) I have searched the board for advise on this device DS1820 and I can see many mention it, however none seem to cover my specific question.2) I'm a real noob when it comes to electronics, this is my hobby.Looking to use this device over 1-wire using parasite power, to start with ill just give it its own power supply to avoid any "traps for young players".Ill be using an Ardunio to collect the data from the device.Setup:To communicate with this device the bus master (Arduino?) must start the process by initiating the reset pulse.My question:How does one *time* the reset pulse so that it will fall within the 480 to 960 microsec time frame? This is required each time you want to communicate with the device, and timing becomes even more important (with other operations) when using parasite power to fill the internal cap.Intended use:Simply experiment with logging the temp in the office environment over time.ThanksDan

author: dr.diesel
author_rank: Super Contributor
timestamp: July 30, 2013, 01:59:53 pm
content: Dan, there is already a proven library for 1-Wire devices:http://playground.arduino.cc/Learning/OneWireFrom there you can dig through and examine how it works if you wish. Otherwise that will get you going in about 5 minutes time.

author: dan20n
author_rank: Newbie
timestamp: July 30, 2013, 02:10:14 pm
content: Thanks dr.diesel for the quick reply it's exactly what I need to get it working.

author: dr.diesel
author_rank: Super Contributor
timestamp: July 30, 2013, 02:19:21 pm
content: Not a problem, and welcome to the forum! Lots of good stuff and people here, don't hesitate to ask.

author: Thor-Arne
author_rank: Unknown
timestamp: July 30, 2013, 07:05:31 pm
content: Hereis a working example using the DS18S20 and DS18B20.
Dallas DS2433 software modded in English, searching for an DS2431 equivalent - Page 1
Forum section: electronics / projects

author: coromonadalix
author_rank: Super Contributor
timestamp: October 08, 2022, 01:51:43 pm
content: HiNot sure it's the good placeHere's the chineese hacked /modded in English software for the 1-wire DS2433 eeprom, hacked / modded the windows size and a few things ...functional with the 1 wire librairies installedI got it when i've bought an usd to 1 wire adapter on AliExpress ....The only thing i could not change is the message status window pane when reading and programming ....I'm not a fan of Arduino or Raspi DIY readers / libraries / sketchs etc ... i need a simple piece of software like this one, there are / was some Baidu links, but not accessible for meI can do with the 1 wire viewer included with the 1 wire libraries BUT ...thks

author: ARF
author_rank: Regular Contributor
timestamp: May 31, 2024, 02:12:19 pm
content: This software doesn't have any settings... Can you send a link to this 1-wire adapter?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 01, 2024, 01:34:16 am
content: https://www.aliexpress.com/item/1005003328560403.html?https://www.aliexpress.com/item/1005003360053572.html?
DAM11W1S connector dimensions (for SRS PRS10 or Efratom FRS) - Page 1
Forum section: electronics / projects

author: matthuszagh
author_rank: Frequent Contributor
timestamp: March 03, 2023, 07:30:58 pm
content: I'm designing an adapter board for an SRS PRS10. This uses an ITT Cannon DAM11W1S connector. Unfortunately, I'm having trouble finding dimensions for a footprint. There's this documenthttps://www.mouser.com/datasheet/2/578/ITT_Cannon_D_Subminiature_Products-1869325.pdf, but I don't see footprint dimensions in there for this part.I have a part in front of me, which I can measure, but it would be nice to have the information in a technical drawing to be sure.Does anyone have data on this?ITT Cannon provides a 3D model by request only. If that works, I'll post the results here.

author: matthuszagh
author_rank: Frequent Contributor
timestamp: March 04, 2023, 05:28:25 pm
content: This catalog has the footprint (https://www.mouser.com/datasheet/2/578/ITT_Cannon_D_Subminiature_Catalog-1549782.pdf). I've attached the relevant info here. The signal contacts are 0.030in. I believe the part number for this is DAM11W1SN. I don't know what the part number for the PCB version of the coax insert is.

author: aholtzma
author_rank: Contributor
timestamp: July 04, 2023, 04:03:15 pm
content: The Molex part numbers for this are:1731070074 body1731120048 plugI built one of these PRS10 breakout boards a while ago and those are the exact parts I used. I should put the Eagle files up on GitHub.
Damaging a LDO through powering the Ouput? - Page 1
Forum section: electronics / projects

author: johnnyfp
author_rank: Frequent Contributor
timestamp: August 21, 2013, 05:13:54 am
content: I put togetherthis circuitthat has a Microchip which I program from a PicKit3. I've setup the Pickit3 to supply 3.3v power when programming.My question is, will power on the output but not the input damage the LDO? I'm using aMicrel 5219and can't see anywhere in the datasheet if powering the LDO thorough the output will damage it or if I need to add a diode to protect it.I can recall somewhere that doing so does in fact damage it. Reason I'm asking is that now the LDO is only supplying 2.7v instead of the expect 3.3v which tends to lead to the conclusion that it indeed does damage the LDO if 3.3v is present on the Output but nothing on the input.Cheers

author: hlavac
author_rank: Frequent Contributor
timestamp: August 22, 2013, 06:37:58 am
content: It is quite common for linear regulator pass transistor to be damaged by reverse current from output to large input filtering cap, or by negative voltage. A few regulators have built in protection for that but not many.You are supposed to put one reverse diode across the output and another across the regulator back to the input cap to protect the regulator.
DAQ card with external clock - Page 1
Forum section: electronics / projects

author: kaptronika
author_rank: Newbie
timestamp: March 08, 2018, 01:04:12 pm
content: Hello all!My first post here, so please be lenientGet to the point. I am working on a project at university which deals with optical fiber sensors but that's irrelevant now. I have a problem with signal processing: we have two photodetectors for two optical signals, where one represents the signal from the optical fiber sensors and the second is from an auxiliary interferometer. The photodetector output is signal with varying voltage from 0-10V based on the optical power. The thing is:I want to acquire the signal from the sensors BUT it needs to be sampled when the auxiliary signal crosses zero voltage. To be specific, the auxiliary signal is cos signal with frequency around 1MHz which may vary 10% around that frequency. Therefore, I need a DAQ card with external sampling clock for the ADC. However, due to higher frequency and satisfying the Nyquist theorem, USB cards cannot be used because they have limited bandwidth. Also I need to acquire data for about 0.5s.I was looking for such DAQ cards and they are very expensive like NI-6115 from National Instruments.There is also Red Pitaya, which has external sampling clock ability according to this linkhttps://redpitaya.readthedocs.io/en/latest/developerGuide/125-14/extADC.htmlHowever, the ADCs LTC2145CUP-14 have 1MHz minimum sampling frequency. Don't know what would happen, if that sampling frequency was lower than 1MHz (from the auxiliary signal).So question is: Do know any DAQ card which has external clock input? Or any ideas how to overcome this problem?Thank you.
Dark IR BGA machines - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: November 07, 2022, 02:06:40 pm
content: Hi,I have seen some BGA rework station with Dark IR emitter technology, I want to know if we have chines manufacturer of these Dark IR emitters? also If you have any experience using these machines, regarding the quality and usage of these machines it would help a lot if you tell your user experience with them.Do you recommend them over the conventional Hot air versions?
Data Acquisition Library for Python and Arduino Due - Page 1
Forum section: electronics / projects

author: powerDaq
author_rank: Newbie
timestamp: January 06, 2025, 09:48:17 am
content: Hello EEVblog community,I’m excited to share a project I’ve been working on:daqopen-lib. This open-source library simplifies data acquisition, making it easier to handle medium-speed streaming ADC data for various applications.Why I Built It:Many projects require reliable and efficient data acquisition tools. I created daqopen-lib to streamline this process, starting with support for the Arduino Due, leveraging its high-speed ADC and USB 2.0 connectivity. It is a core part of my main project for power (quality) analysis and can be used separately for many other applications/projects which requires continous data acquisition.Features:ADC Driver: Easily communicate with Arduino Due and manage data using NumPy arrays.Circular Channel Buffer: Efficiently handle and store data for analysis or visualization.DAQ-Info Class: Description for data acquisition properties like scaling, samplerate.firmware included for Arduino Due.Background:I use the Arduino Due (although it's more than 10 years old) because it has three main advantages for my use-cases:ADC Speed up to 1 MS/sDifferential inputs with 12 bit resolutionUSB 2.0 interface to connect to edge-device like Raspberry Pi and transfer with ~16 MBit/sI use the native USB-interface and collect the data on the edge device via simple /dev/ttyACM0. The "driver" application is written in Python and converts the streamed packages to numpy arrays. Using the daq-zmq server-client allows you to decouple time-critical data reading from further processing in your target application.How to Get Started:The library is available on GitHub (https://github.com/DaqOpen/daqopen-lib), and documentation and tutorials can be found here:docs.daqopen.com.Related projectsI'm actively developing and using this library for my main project PQopen. This will be an open source power (quality) analyzer for power networks. It is still under development.Some example apps, including the daq-zmq-server, are available in a separate repository:https://github.com/DaqOpen/daqopen-appsI’d love to hear your thoughts, suggestions, and ideas for improvement. Looking forward to your input!Best regards,Michael

author: RoGeorge
author_rank: Super Contributor
timestamp: January 06, 2025, 10:03:26 am
content: Wow, thank you!Will give it a look. Is there any way to add a timestamp to the data?

author: powerDaq
author_rank: Newbie
timestamp: January 06, 2025, 10:20:22 am
content: Quote from: RoGeorge on January 06, 2025, 10:03:26 amI mainly use the daq-zmq-server.py (https://github.com/DaqOpen/daqopen-apps/blob/main/daq-zmq-server.py) as application, which adds a timestamp to the data with relatively low latency. In the receiving main application you can rebuild the timestamp and extend it to a continous one with the AcqBufferPool. There is no "real" example available for now, but you can get an idea from the methodstart_transferfrom the client apphttps://github.com/DaqOpen/daqopen-apps/blob/main/daq-zmq-viewer.py.
Data collector with Sp32, RS485 and RS-RA radiation transmitter - Page 1
Forum section: electronics / projects

author: Stalyn
author_rank: Newbie
timestamp: May 28, 2025, 05:04:08 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
Data logging software for Brymen 25x using Qt5 - Page 1
Forum section: electronics / projects

author: luh2112
author_rank: Newbie
timestamp: March 25, 2015, 09:47:18 am
content: Just a quick note for now.I'm working on data logging tool for Brymen 25x series.It's written in C++ using QT5 toolkit under Linux.Currently it's in usable-draft state.Current features:- acquiring data in manual and interval mode- saving data to text file and to clipboard- plotting data on the graphgit:https://github.com/luh2112/Lab-MateI must admit, the code is quite messy at the moment.Please let me know if anyone is interested in this kind of tool, and what features do you expect.

author: dom0
author_rank: Super Contributor
timestamp: March 25, 2015, 10:42:05 am
content: It's probably a better devotion of resources to contribute tools and drivers to an umbrella project like sigrok, since more people can use your tools, if they work with any DMM supported by a project like sigrok.

author: android
author_rank: Regular Contributor
timestamp: March 25, 2015, 01:07:14 pm
content: I recently wasted a day trying to bludgeon sigrok into logging anything at all (from a BM869) under Ubuntu. What you've produced looks vastly superior IMHO, so go for it. Looking forward to seeing it on github

author: luh2112
author_rank: Newbie
timestamp: March 25, 2015, 01:36:22 pm
content: Your opinion on sigrok reflects mine quite closely.But there's no reason this program couldn't use sigrok's drivers as input for other meters.
data on 3DU11 phototransistor - Page 1
Forum section: electronics / projects

author: bobdring
author_rank: Contributor
timestamp: May 15, 2018, 03:37:31 am
content: Hi,I'm looking for data on a 3DU11 phototransistor. This is a real part number as I do get some google hits on it.The part is mentioned in a patent of a pest exterminator that i'm trying to repair/improve.My Googlefu has let me down and I can't find any datasheet on it. Does anyone know it?Bob

author: bobdring
author_rank: Contributor
timestamp: May 15, 2018, 07:29:40 am
content: Hi blueskull,Thank you for the info.The patent that I was reading Patent No.: US 8,024.888 B2 said that the 3DU11 had an integrated preamp which looks to be a red herring."the IR receiver is preferably embodied as an IR photo transistor such as a 3DU11 pin diode with preamp"I would love to know how you found the data on it, because I tried really hard to find it and I need a few pointers for next time.Bob

author: bobdring
author_rank: Contributor
timestamp: May 15, 2018, 08:11:09 pm
content: Hi blueskull,Thank you for the URL. I had actually been to that site, but via a search link not through the home page and I couldn't see it! Now I can see the data.I'm using Chrome to do the translations to English but of course it can only do text not the text in images so that leaves me at a great disadvantage to a fluent Chinese engineer.Bob
Data Over Low Voltage AC Power - Page 1
Forum section: electronics / projects

author: petersanch
author_rank: Regular Contributor
timestamp: November 12, 2020, 12:38:33 pm
content: Hello All,I have a 24V AC power supply powering several devices in parallel. Each device has a full wave rectifier and Ldo to power a microcontroller and sensors.I want to send short commands (at least 8 bytes in size) to the devices using the AC power lines. There will be one transmitter connected tothe AC power lines and all other devices will only listen and will decode the commands.Is there a bare bones circuit for this without additional encoder or decoder chips? Does this way of communication have a name?Cheers

author: TimNJ
author_rank: Super Contributor
timestamp: November 12, 2020, 09:28:55 pm
content: If you didn't know of these already:https://en.wikipedia.org/wiki/Power-line_communicationhttps://en.wikipedia.org/wiki/IEEE_1901I'm not sure using at 24VAC makes any difference or not.

author: Marco
author_rank: Super Contributor
timestamp: November 12, 2020, 10:59:34 pm
content: There'san articleon Electronic Design for a DIY solution.Though I think I'd use Manchester encoding rather than OOK.

author: petersanch
author_rank: Regular Contributor
timestamp: November 13, 2020, 09:41:19 am
content: Quote from: Marco on November 12, 2020, 10:59:34 pmI like this circuit but Im not sure if it will work for AC power input (I dont have previous knowledge to this kind of communication). Can some one advise if rectified AC into a such circuit will work? Does it need to be conditioned? Cheers!Quote from: TimNJ on November 12, 2020, 09:28:55 pmAfter browsing about PLC it looks like the chips that are made for it have MAC or ethernet outputs. Can PLC be implemented with jelly bean components or will it need PLC chipsets? Cheers!

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2020, 11:41:59 am
content: Quote from: petersanch on November 13, 2020, 09:41:19 amI don't see why it shouldn't work with AC. It will need to be powered by a rectifier, smoothing capacitor and regulator. The AC blocking/coupling inductors and capacitors, should be connected to the AC side of the rectifier.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 13, 2020, 12:49:11 pm
content: All you really need are some bandpass filters and a coupling circuit. Take a look at X10 or UPB for some idea of how that can work. If you do data transmission near zero crossings, you won't even need series inductors before the rectifiers since the diodes will be off during that time and act as high impedances.

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2020, 01:29:39 pm
content: Quote from: NiHaoMike on November 13, 2020, 12:49:11 pmThe main transformer could be a lower impedance and there might be other low impedance loads too.

author: petersanch
author_rank: Regular Contributor
timestamp: November 16, 2020, 09:18:36 am
content: Quote from: NiHaoMike on November 13, 2020, 12:49:11 pmQuote from: NiHaoMike on November 13, 2020, 12:49:11 pmThanks for the tips! Cheers
Data sheet or information on VCXO - Page 1
Forum section: electronics / projects

author: ralphk
author_rank: Newbie
timestamp: April 13, 2017, 12:41:38 am
content: Hi,I have a 500Mhz VCXO that I picked up a hamfest (amateur radio swapmeet) for free, but have had a devil of a time finding anything at all about it. I've checked google, ebay, mailing lists (e.g. time-nuts) but can't find anything at all.The unit is from Vectron Industries Part No. CO 533ME, the unit measures about 70mm x 45mm x 15mm with 6 pins, 2 of which are ground. It is still attached to the a small pcb module but the silk-screen gives no hints about what it is. Also the board is multi-layer so I'm uncertain about some of the connections with the passive components. In the second photo is shown the back of the pcb module, I'm assuming that the oscillator output pin is the one with the ring of through-hole vias?Note that I have found a reference to a Vectron model CO-233ME, but they are not at all the same units.Thanks for any help!Ralph