hybridfree/eevblog-posts huggingface dataset:
Dry relay contacts for Digital Outputs - Page 1
Forum section: electronics / projects

author: rockbassist90
author_rank: Contributor
timestamp: March 12, 2015, 05:44:13 pm
content: Before asking how, I will present my case.4 relays, each is represented by an LED, red indicates open, green indicates closed.Open each relay has an impedance >10M Ohms, closed < 1 Ohm...but since there is no voltage or current bias...I cannot simply take the relay output to obtain the "logical state".Any suggestions?I was thinking of perhaps using a resistor network with a power source. These outputs would feedback to our Digital I/O.

author: picandmix
author_rank: Frequent Contributor
timestamp: March 12, 2015, 08:40:15 pm
content: Use a relay with cross over contacts, which many are, so one contact is wired to digital + and the other to 0v with the pole being the output.To enable you to have the indicator leds then you need a double pole relay so its a whats called a DPCO , again which many are as standard., and still lo cost

author: miguelvp
author_rank: Super Contributor
timestamp: March 13, 2015, 07:39:19 am
content: One LED pulled high, the other one pulled low?

author: picandmix
author_rank: Frequent Contributor
timestamp: March 13, 2015, 10:37:40 am
content: Quote from: miguelvp on March 13, 2015, 07:39:19 amThink they want something like this ..

author: rockbassist90
author_rank: Contributor
timestamp: March 13, 2015, 01:28:13 pm
content: I'm restricted to the relays already in the chassis. This is a third party module that we are using for an onsite application.

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 13, 2015, 01:42:51 pm
content: Quote from: rockbassist90 on March 13, 2015, 01:28:13 pmWhy don't you draw a schematic of what is currently in place, so that we all have a bit more information of the starting point.

author: 37electrons
author_rank: Newbie
timestamp: March 13, 2015, 02:38:51 pm
content: So you want to add an external LED circuit to your existing dry-contact outputs, right?You havent provided details so i've made the following assumptions:a/ you have SPNO relays (single pole, normally open)b/ relays contacts are on the high-side of your load (i.e. they connect/disconnect VCC, not GND)c/ VCC is low (5~12Vdc, not 220Vac)d/ the load resistance is relatively high to have voltage drop > 2~3V let's saye/ the load is not inductiveIf all is true then something like shown on the attached picture should work for you.
DS0150 - mini digital osciloscope improvements and how to improve more - Page 1
Forum section: electronics / projects

author: Matthew98
author_rank: Regular Contributor
timestamp: February 20, 2017, 08:35:51 pm
content: Hey, guys !Today my DS0150 arrived. Its dirty cheap digital osciloskope (around 25 dollars) and I absolutely love it ! They left little space inside the case, so i improved it a bitNow its fully portable with its 700mah battery. The stepup converter is probably not the best for osciloscope, but it will have to doHere are some pics :But i still get lots of static, that the scope did on clean source of power. The knob for adjusting the static didnt really do much, so i left it where it looked same both on top and bottom. I was thinking, if better brands of the electrolytic capacitors or replacing ceramic capacitors with better ones would help?Thanks for anysuggestions.If you want to make this power managment for yourself, here is the part list i usedNow keep in mind, that TP4056 will charge the battery (Lion or Lipo) 1A by default. You have to change resistor value to reduce current. Charge a cell with max of 1C (1C is capacity it has eq. 600mAh cell - charge with 600mAh max, if not mentioned differently in datasheet of battery) Im including datasheet with chart for those values here :http://www.haoyuelectronics.com/Attachment/TP4056-modules/TP4056.pdfParts :Tp4056 - I used one, that has battery protection circuit built in.http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XTp4056.TRS0&_nkw=Tp4056&_sacat=0Stepup converter - Chep one will do (Mine is older version of MT3608, i guess. It was laying at shelve for some time), you need variable one, so you can set it to 9V at this case.http://www.ebay.com/sch/i.html?_odkw=stepup+convertor&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xstepup+converter.TRS0&_nkw=stepup+converter&_sacat=0Lipo battery - I used 700mah one, but it bearly fits. It might get a few tries to get the one, that fits.Switch- I did not really measured the current going into converter, but it will surely by under 1A, it might be even under 500mAFiltration capacitor - I used 470uF Hope its doing something ...And thats all, folks... really easy mod, thas is applyable to lots of projects. Go ahead and buy bunch of convertors and chargersAllright, the step up converter does make a differance ...Without :With :Any idea, how to eliminate that ?

author: qu1ck
author_rank: Regular Contributor
timestamp: February 26, 2017, 08:05:16 am
content: I'm not sure you actually have an issue with step up module. In your first photo "without" you actually have higher Vpp noise levels than "with" the module.Anyway if you want to try to reduce ripple try these 2 things:1. Put a choke on output2. Step up voltage to higher than 9v and put an LDO on output.One or the other, or both should help with ripple, however you will always see noise on this scope, it's unavoidable.

author: Matthew98
author_rank: Regular Contributor
timestamp: February 26, 2017, 12:12:00 pm
content: Sorry, its my fault...The noise is higher of curse with the module...Thanks !
DS1220 NVRAM replacement not working in all devices - Page 1
Forum section: electronics / projects

author: Amper
author_rank: Frequent Contributor
timestamp: June 16, 2019, 09:33:43 am
content: Hi!I have a wired Problem and even after quite some time cant get my head around why this could be.A few years ago i upgraded the HP3458a i had back then to F-Ram (FM16W08) to replace the old problematic NVRAM (DS1220). I did it according to the idea fromhttps://xdevs.com/fix/hp3458a_u4/. This worked absolutely beautifully without any problems right from the start.Now recently i have to repair some parts in dental chairs (sirona S1). Those are chairs from the 80s-00s and are still regarded to be the very best you can get, though over the last few years the supply of replacement parts is drying up.One of the cards responsible for memorizing the seat position is using a DS1220 and obviously they are mostly dead by now so i decided "hey, i have done this before", made myself a replacement board as in the 3458a and plugged it into the socket. Sadly it just wont work. Plugging in deleted NVRAMs it will perform as required, even using the completely scrambled one i took from the multi meter works like a charm so its not an issue of some formatting missing on the device.Can anyone tell me if there is a difference between the parts i have overlooked? The only one i could sport is the extended voltage range of the fm16w08 and that it is faster, though both properties should not collide with replacing an older part.Sadly i dont own a logic analyzer and taping into the board while running is pretty much not possible. Worst case ill have to build some sort of extention cord for the edge connector but id prefer not having to do that.Thanks in advance for any help!cheers
DS1307 clock chip won't oscillate - Page 1
Forum section: electronics / projects

author: Deckert
author_rank: Regular Contributor
timestamp: July 16, 2013, 10:49:11 pm
content: Hi!I'm building a control circuit that needs an RTC along with my selected uP. Everything works fine from the uP perspective, except for the DS1307 itself. The 32kHz oscillator simply doesn't seem to be working.As per the data-sheet, the crystal (with a specified load capacitance of 12.5pf) is connected directly to pin1 and pin2 of the chip:I've done this on a breadboard like this:Thinking that there may be some stray capacitance on the breadboard, I also tried it by soldering the crystal directly to pin1 and pin2 of the chip:Still, no oscillation - measuring with a scope on the 1Hz output on pin7.Any ideas why it won't oscillate?Does the chip have to be addressed/configured before the oscillator will start up?--deckert

author: Niklas
author_rank: Frequent Contributor
timestamp: July 16, 2013, 11:42:31 pm
content: Have you checked with a scope if there is any activity on the crystal's pins? The datasheet says that the output must be enabled before you get anything. Chech the section about the control register and the SQWE bit. You should also ground the Vbat pin in the second picture, the one with the soldered crystal, so that the internal supply failure detection circuitry is not tricked.

author: Deckert
author_rank: Regular Contributor
timestamp: July 17, 2013, 12:22:18 am
content: Hi Niklas,Quote from: Niklas on July 16, 2013, 11:42:31 pmShould have added that I did probe the pins (using a differential probe, so no inadvertent grounding of the circuit). I should have the DS1307 control code done by tomorrow to see if the chip needs to be "active" in any way, but my gut tells me something else is wrong, since the oscillator should just start up by itself.And just to double-check, I used two (new) chips and two different crystals. Oh, and I tested the crystals using a classic dual-inverter oscillator with a 4069 - both crystals start up fine.Agreed about the batt.pin in the second picture - I set it to 3V using a simple R divider (since the current draw is negligible), but made no difference.--deckert

author: David_AVD
author_rank: Super Contributor
timestamp: July 17, 2013, 01:37:39 am
content: From the data sheet:Quote

author: Deckert
author_rank: Regular Contributor
timestamp: July 17, 2013, 08:37:05 am
content: Quote from: David_AVD on July 17, 2013, 01:37:39 amHa! It's even bold in the datasheet and yet I still missed it - thanks for highlighting it .. againWill finish the control code this evening and feedback here. This project is part of an electric blanket controller project that I've been wanting to complete for some time!--deckert
DS2715 NI-MH Charge Controller Design Ideas - Page 1
Forum section: electronics / projects

author: nhoj4
author_rank: Newbie
timestamp: April 24, 2018, 01:28:09 am
content: Hello!I am attempting to design a system that charges a 6 cell 1800 mAh NIMH R/C car battery wirelessly with the DS2715 charge controller by Maxim. I am trying to modify their linear charging design for a 6 cell battery.In the data sheet they specify the circuit for charging a 3 cell pack (in series) linearly (with a 6 V supply), and I have built the circuit accordingly. The only info in the data sheet regarding changing the cell count is the voltage divider on the Vbat pin for detecting a single cell's voltage. I assume that for charging 6 cells I would double the supply voltage for 12 volts? I know that the IRF can handle this change but am unsure about the other components and do not want to damage the IC.When I supply the circuit with 6 Volts and use the original resistive divider for 3 cells, the LED is off (as it is supposed to be with no battery connected). But, when I use the 6 cell resistive divider and supply 6 V the LED flashes at 4 Hz indicating that there was a fault. I am assuming this is because the circuit really does need 12 V. I have a LED that is suited for 12 V on the way but wanted to see if anyone has used this IC for a similar design and could offer some insight.I have contacted Maxim for support but they have not gotten back with me yet. Thanks in advance.Part link:https://www.maximintegrated.com/en/products/power/battery-management/DS2715.htmlDatasheet:https://datasheets.maximintegrated.com/en/ds/DS2715.pdf
DS2788 battery gauge for lipo batteries - Page 1
Forum section: electronics / projects

author: kasunt
author_rank: Newbie
timestamp: December 18, 2012, 11:03:04 pm
content: Hi all,So I decided to go with this chip DS2788 which has a 1-wire interface to measure the battery voltages. It seems its adequate for my task and its not too pricey either. I also found a DS2788 Evaluation Kit by Maxim and their schematic isnt very clear and not easy to understand what the kit is doing. I don't have much knowledge about electronics but I guess you learn by getting your hands dirty.Can someone please help me to get an understanding of the schematic ? I have attached the datasheet below. Its not easy to see the parts they are using either.

author: kasunt
author_rank: Newbie
timestamp: December 19, 2012, 03:41:44 am
content: Kind of figured out why P-channel and N-channel FETs are needs.But do I go about calculating the sense resistor value ?

author: bfritz
author_rank: Regular Contributor
timestamp: December 19, 2012, 08:25:22 am
content: So... You appear to only be looking at the datasheet for the EV-Kit. I suggest you look at the datasheet for the DS2788 itself.I think you'll find it explains many things:http://datasheets.maximintegrated.com/en/ds/DS2788.pdfNote that the datasheet explains how the circuit works, and what the is going on in the schematic.As far as how do you choose a sense resistor value...Think about the following:What is the full scale voltage for the current measurement A/D? (Start reading on page 8 of the datasheet mentioned above.)What is the range of current you need to fuel gauge? Most devices will never consume less than some lower limit, and will never go above some upper limit. The resistor you choose needs to allow for all those currents to be measured.In general a lower resistance sense resistor wastes less energy, while a higher value sense resistor makes it easier to measure low currents accurately.
DS9481P-300 - did anyone use it in I2C mode? - Page 1
Forum section: electronics / projects

author: dobsonr741
author_rank: Frequent Contributor
timestamp: February 18, 2024, 07:32:04 pm
content: I fond no useful examples on how to use this strange little Maxim I2C/1Wire adapter. Has anyone used it to talk to I2C devices?

author: dobsonr741
author_rank: Frequent Contributor
timestamp: February 19, 2024, 03:39:03 am
content: To answer my own question: no examples b/c the board as a USB is I2C converter is useless. Hopped over a QT Py with Circuitpython and in business in no time.
DSADC (MCP3465R) Input vs. Vref - Page 1
Forum section: electronics / projects

author: 8086
author_rank: Super Contributor
timestamp: February 03, 2024, 05:53:55 pm
content: I'm working on a RTD temperature measurement design with the main focus of low cost (for the electronics). Using PT1000 type RTD. 1C accuracy is fine.The MCP3465R delta-sigma ADC came up on Mouser as the lowest cost option with Vref input for ratiometric measurement.I have come up with the circuit attached which by calculation gives appropriate values. It's based on the circuit in section 2.1 of this TI appnote:https://www.ti.com/lit/an/sbaa275a/sbaa275a.pdf. R9 is 0.1% 25ppm. Please ignore the potentially redundant filtering.My question is this - am I allowed to have the absolute value of Vref+ lower voltage than either of the ADC differential inputs (CH0, CH1) with this part? Or must Vref+ be higher than the highest ADC input? I have checked the MCP3465R DS and I think my circuit is valid but I wanted to double check with the forum.Thanks in advance

author: Kleinstein
author_rank: Super Contributor
timestamp: February 03, 2024, 07:31:20 pm
content: With most SD ADC it should be OK. Otherwise the neg input side would be essentially limited to ground to use the full range with a gain of 1.One may want extra diodes or so for protection.

author: Nominal Animal
author_rank: Super Contributor
timestamp: February 04, 2024, 03:55:12 pm
content: Quote from: 8086 on February 03, 2024, 05:53:55 pmLCSC sellsMAX31865ATP+Tfor 2.75€ apiece; a known good PT100/PT1000 resistance-to-digital converter designed for the purpose. (At Mouser, 7.50€ apiece. Ouch.)If you create and assemble your board at JLCPCB, they sell MAX31865ATP+ for $2.44 apiece (but minimum 4 units) when assembled there.In any case, you'll probably want to use 3/4 wire sensors, and implement the 12th and 9th order polynomials for accurate resistance-to-temperature conversion (seeITS-90); or, alternatively, approximate it either piecewise linearly or piecewise cubicly (with a table in ROM/Flash). Although most like to use floating point for this, it can be done using 32-bit integer fixed point math too.
DS3231 RTC - Page 1
Forum section: electronics / projects

author: hsynylcn
author_rank: Contributor
timestamp: April 28, 2025, 09:11:02 am
content: Is it normal for the SQW pin of the DS3231 RTC module to not produce a proper square wave?

author: Peabody
author_rank: Super Contributor
timestamp: April 28, 2025, 02:23:30 pm
content: No. But the SQW output is open drain. Do you have a pullup resistor on that line?

author: hsynylcn
author_rank: Contributor
timestamp: April 29, 2025, 12:17:24 pm
content: The problem was solved when I added the pull-up resistor. Thank you very much for your help.
DSI to V-By-One bridge IC ideas? - Page 1
Forum section: electronics / projects

author: StefanHamminga
author_rank: Contributor
timestamp: March 10, 2022, 06:52:42 am
content: Does anyone have suggestions for a single-chip converter between DSI (MIPI D-PHY or C-PHY) to V-By-One 8-lane?I'm looking for a chip that can be integrated in a carrier board for a Snapdragon 845 module, so the board can directly connect to a V-By-One 4K panel with an 8-lane interface. The panel doesn't support the newer and faster HS 2-lane solutions and sadly I can't change it for an eDP panel. I've come across IP solutions, but that's a bridge too far development time wise.
DSLogic Pro Problems with clock - Page 1
Forum section: electronics / projects

author: mriPaul
author_rank: Contributor
timestamp: November 13, 2019, 04:49:06 am
content: I have the DSLogic Pro and it works well so far. I have data with two pins. A CLK and data. I now have data I need to decode. I set the software to SPI and MOSI and 8bit protocol to decode the data. My data starts on a clean 8 bit packet. However, the software appears to decode the data with some random 5-6 bit protocol. I have attached a picture of the software showing my parameters.Any ideas?

author: mriPaul
author_rank: Contributor
timestamp: November 13, 2019, 01:51:46 pm
content: I found my issue. I had signal bounce. After zooming the data, I saw extra "square waves".
DSO 138 Oscilloscope DIY kit working good - Page 1
Forum section: electronics / projects

author: lordvader88
author_rank: Frequent Contributor
timestamp: April 05, 2017, 10:28:23 pm
content: I ordered it from ebay for $25 or so. The SMD parts were already soldered on, I don't mind since I've yet to mess with them. Soldered the rest of it together fairly quickly and without issue, even the microUSB adapter. Powered it up and didn't think it was working right at 1st, but I missed soldering a 2nd jumper closed. So now its working good it seems.Very neat little scope to compliment a DMM without having to power up a full size, full cost scope (my Tekronix is still in pieces until I hopefully repair it (1 channel still works tho))Lots of little hobby stuff I can use this for, but now its supper cooking time

author: macboy
author_rank: Super Contributor
timestamp: April 06, 2017, 03:47:45 pm
content: I bought and assembled one of these too, mostly just for some through-hole soldering fun. It worked surprisingly well. I gave mine away -along with a bunch of other stuff - to a foreign exchange student that had been staying with family here, and was going into EE back home. I'm thinking of buying another one for my 8yo son.Note there are a lot of (illegal) clones of this. Try to buy a genuine one, there isn't much price difference if any. This is quite unlike Arduino, where clones are legal and encouraged, but cost at least 90% less than the original.

author: lordvader88
author_rank: Frequent Contributor
timestamp: April 06, 2017, 05:19:44 pm
content: For the price, I would hope soon this level of visualizing a signal should be standard on good multimeters.Something else really useful to me on this is, I'm powering it from a 12V powerpack. And I the battery header is connected right to the other DC power input. So I can use that to power little breadboard experiments. So it cuts down on wire clutter.
DSO very noisey ( Not sure I am on right FORUM ) - Page 1
Forum section: electronics / projects

author: MrsR
author_rank: Regular Contributor
timestamp: June 08, 2012, 07:36:23 pm
content: H1! Guys,Just joined didn't know the sight existed till yesterday.I have an ATTEN DSO 20Meg's which is all I need as I am mainly working in 50Hz to 2kHz.regionThe ATTEN is re-branded by Digitech as a QC-1932.The problem is that the Scope has developed noise both channels 120Mv+ to 12mV-This is after recalibration no leads/Probes attached.Anybody own one or have an idea what is causing this. When I first got it to replace my Analog Scope, it was very clean after about 2 months of use then gradually got worse.

author: saturation
author_rank: Super Contributor
timestamp: June 08, 2012, 08:31:08 pm
content: Alas, this sounds like a hardware issue. Does the scope have a factory reset option in the firmware and a self-calibration? If so, run them and report back. Any photos of the noise will help. Good luck.

author: MrsR
author_rank: Regular Contributor
timestamp: June 09, 2012, 01:55:36 pm
content: SATURATION,Thanks for the reply, I can take a screen shot and post it, I studied the wave form more closely and it looks like it is digital varying in pulse width and time although the pulse width is the greater variance or factor may be a better word I was hoping it would be an Analog problem as then it would be more than likely a faulty Capacitor or Inductor/Choke.It is always hard when it is a piece of test equipment that would be used to help solve the problem.I talked to a chap at Jaycar the supplier and I got the impression that they don't have a clue how to repair it or it may have been just him.

author: saturation
author_rank: Super Contributor
timestamp: June 11, 2012, 03:07:50 pm
content: You're welcome. Sorry to say, given all the devices we see here made by Atten and Siglent, there are other makes of competing products I would try before settling on Atten.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 12, 2012, 09:15:51 am
content: Much as I delight,as a diehard analog person,in pointing out the shortcomings of DSOs,I wonder if there has been a change in RF noise levels in the vicinity lately,with the onset of winter.Some reverse cycle airconds cause RF interference,which you may have not seen on your analog 'scope,if it was lower in bandwidth.I remember,many years ago,that we got upset,at my then workplace,when our newly provided 7000 series Tektronix had higher apparent noise than the 545B it was meant to replace.We were working at a CH2 TV Station with the vision carrier at 64.25 MHZ fairly invisible to the 545B,but not the new one.
DSP amp, will my schematic work? - Page 1
Forum section: electronics / projects

author: Michaelaudio
author_rank: Regular Contributor
timestamp: June 27, 2022, 11:47:47 am
content: So this is my DSP amp i designed, mostly from the typical applications in the datasheets, but maybe i missed something.Im not 100% shure about the DIR9001 Part, since im a noob in digital things, will it work like this?The Attiny in the Power/controll section is for switching 5V and 24V Off, when no music is playing for 15minutes. I plan on using the ADCs of it, to sense the audio signal from the Input of the DSP, via the 2 diodes, is it reliable to do it like that?I will get help with the programming of the Attiny.As for the rest, if something is wrong, im happy to know it.

author: jwet
author_rank: Frequent Contributor
timestamp: June 27, 2022, 06:05:37 pm
content: There is a problem with your input muxing and detector circuit I think- there is no DC path to center the signal though the switch. Your input is AC coupled comes though a the amps, is AC coupled to the MUX which is run on 15 and ground. It doesn't have any DC bias. You need to have some kind of baseline restorer somewhere. As it is I think, think the DC level will fall in a diode drop below the AT Tiny power supply. Also, you might want to put a series resistor and maybe a low pass in the diode sense path. Any digital noise on the AT tiny input will get coupled directly into the audio path through the diode capacitance. Slow this down and isolate it in some way. You also want some resistance in this path so you don't latch up the AT Tiny on big audio swings. It looks good at a first cut at a board. I think I would breadboard up your input and AT tiny stuff and look at swings

author: Michaelaudio
author_rank: Regular Contributor
timestamp: June 28, 2022, 09:33:22 am
content: Oh yes, i totally missed that. Can i just bias the VDD of the CD4052 with 7,5V? It may work but im not really sure.Eddit: i did some thinking, this wont work i guess. I'll just leave the caps of the op outputs away, and bias the BT Signals. That will work for sure and the caps in the DSP Inputs should be enough.Yea, the diodes were stupid, i wanna sense even a verry low audio signal, so i did it for the left and right Channel, as shown in the picture.
DPS5005 PSU  - Page 1
Forum section: electronics / projects

author: lolimpol
author_rank: Contributor
timestamp: November 13, 2017, 04:35:09 pm
content: So I want to create a DPS5005 computer controlled PSU, in a wooden enclosure. but I would like to know what "pre" power supply I need for the full range, like this one:https://www.banggood.com/200W-7A-6-35V-To-6-55V-High-Power-Step-Up-Boost-Converter-Charger-Module-With-Aluminum-Case-ME3L-p-1019833.htmlBecause its the only one I could find under 10 euros, that goes to 55V. Because I have some Laptop PSU's left over.But will I need a fan to cool it in the wooden case?Here's the one I wan't to use: (Option A)https://www.banggood.com/RD-DPS5005-50V-5A-Communication-Function-Constant-Voltage-Current-Step-down-Power-Supply-Module-p-1161704.html
DSPIC30 example tutorial? - Page 1
Forum section: electronics / projects

author: ftransform
author_rank: Frequent Contributor
timestamp: May 23, 2013, 05:15:42 am
content: So I got some DSPIC30's and I was wondering if anyone know about some kind of low-stress example that I could follow to implement some kind of digital filter on some kind of signal.It could be something like connecting a function generator to the ADC and putting a filter, so a certain frequency gets attenuated.I have some theoretical dsp knowledge, kinda, barely, from a few years ago.Something real easy that will likely work and not have me tearing my hair out. I could then play with it. The little amount of DSP work I did involved MATLAB... but having a physical thing, which I could plug the function generator into, would probably keep my interest much more, especially if I could later plug in a microphone or something into it. I just hate working solely in the software, even if its a software thing. Even having a MCU in front of me will probably reduce the levels of stress... don't ask me why.... i dont know... I can't do MATLAB with out it producing some kind of useful result for me, it makes me wanna cry.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: May 23, 2013, 05:23:39 am
content: You could try the Microchip example code library:http://www.microchip.com/CodeExamplesByFunc.aspxA few things there to look at for the dsPIC

author: ftransform
author_rank: Frequent Contributor
timestamp: May 23, 2013, 05:52:00 am
content: Quote from: DrGeoff on May 23, 2013, 05:23:39 amI was looking for something someone tried. I am on thin ice with DSP as it is and the last thing I want is some problematic/difficult app note to push me further away from it

author: poorchava
author_rank: Super Contributor
timestamp: May 23, 2013, 06:09:54 am
content: Quote from: ftransform on May 23, 2013, 05:52:00 amI have tried dsPIC30's and only thing i can recommend is not to use them. They purely suck. Old architecture with 4clk/instruction cycle, horrendous power draw, and as usual tons of hardware bugs. Some default settings of registers are really messed up and cause severe cases of hair pulling and rage. If you want to use Microchip at all in my opinion better go with dsPIC33's, they are simple better. They have their own problems, but are far better than dsPIC30's.Actually In my opinion dsPIC33F's, PIC24H's and PIC32MX's are only useful controllers from Microchip, and this is only when you get them for free or desolder. Otherwise go for ARM, MSP430 or AVR (or 8051, at least they work as intended in most cases...)I'm not totally bashing Microchip: their low power stuff is amongst the best on the market and PPS functionality is something that I loved to work with, but in most cases their products suck.

author: ftransform
author_rank: Frequent Contributor
timestamp: May 23, 2013, 07:14:31 pm
content: I have no problems with my PIC16, it does everything I want...
SOLVED: dsPIC33.... Initial Programming - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 22, 2020, 04:38:26 pm
content: So I populated my dsPIC33EV256GM006 board and attached a PICKit3 and found it could not read the device ID...My PGC and PGD are connected to PGEC2 and PGED2 respectively.I had naively considered that the device would be clever enough to spot PGC and PGD on any of PGEC1,2,3 or PGED1,2,3?Do I need to program FICD ICD Channel bits before PGEC2,D2 will be functional? Is the default well known?

author: voltsandjolts
author_rank: Unknown
timestamp: May 22, 2020, 06:00:13 pm
content: With a blank device the defaults are PGEC1 PGED1 - thereafter selectable in configuration bits that are loaded from top of program FLASH.

author: jaromir
author_rank: Unknown
timestamp: May 22, 2020, 06:17:05 pm
content: For programming, all PGEC/PGED pairs are always active.For debugging, only pair selected by config bits is active.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 22, 2020, 06:53:42 pm
content: I was doubting myself... but kept at it and found my problem was a poor connection on VCAP.Connecting to MPLAB PICkit 3...Currently loaded firmware on PICkit 3Firmware Suite Version.....01.56.07Firmware type..............dsPIC33E/24EProgrammer to target power is enabled - VDD = 5.000000 volts.Target device dsPIC33EV256GM006 found.Device Revision ID = 4006That's a relief.ICD Channel bits can then be programmed.My limited understanding is that for debugging you might have to change the defaults to be correct but for programming you can get away with it which was my assumption.... and happily it works.

author: JPortici
author_rank: Super Contributor
timestamp: May 22, 2020, 06:58:03 pm
content: Was already confirmed by others but yeah, program on any pair, debug only on the selected pair.But don't be a fool and rely on assumptions, read the datasheet and spare yourself some problems..

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 22, 2020, 07:06:45 pm
content: As the OP finally found out, it was not a matter of using the wrong signal pair. As they said the probe was unable to read the device ID, it was just not (at this point) trying to debug anything. It failed at the identification step, which is a common first step for programming and debugging. Failing to read the device ID, if the probe works fine, is usually a hardware problem on the PIC's side.Never had this issue with a bad connection to the VCAP capacitor, but had this with a bad connection to AVDD.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 22, 2020, 07:08:42 pm
content: Quote from: JPortici on May 22, 2020, 06:58:03 pmI consider the datasheet a bit ambiguous on this topic. My interpretation was...s27.6Any of the following three pairs of programming clock/data pins can be used:• PGEC1 and PGED1• PGEC2 and PGED2• PGEC3 and PGED3but it doesn't explictly state anywhere if that is affected by configuration bits.Quote from: JPortici on May 22, 2020, 06:58:03 pm#BeKind Give me a break; this board was designed weeks ago it's only now I doubt myself.
dsp/kalman filter focus forum - Page 1
Forum section: electronics / projects

author: bug13
author_rank: Regular Contributor
timestamp: November 03, 2017, 01:14:16 am
content: Hi guysI am teaching myself Kalman filters following some guides online, but I have many questions. Is there a forum that you use for these sort of questions? thanks guys!!

author: JimRemington
author_rank: Regular Contributor
timestamp: November 05, 2017, 03:47:39 pm
content: Buy, or borrow from your local engineering library, a copy of Dan Simon's "Optimal State Estimation" and work your way through parts 1 and 2. It is excellent.http://academic.csuohio.edu/simond/estimation/
DT-06 serial link over wifi - Page 1
Forum section: electronics / projects

author: roboteux
author_rank: Contributor
timestamp: January 23, 2024, 03:40:13 pm
content: Hi,I want to use 2 DT-06 module to do a serial link between them.But I can't figure out if it is possible.I've ound the documentation to connect a terminal on my PC or android to one module, and send or receive serial data.But I would like to configure 2 modules so that they talk to each other, and I have 2 MCU that can communicate via this wireless serial link.

author: macboy
author_rank: Super Contributor
timestamp: January 25, 2024, 05:05:44 pm
content: It should be possible. One needs to be in AP mode, the other in STA mode. Choose appropriate IP addresses. In addition, one will need to be the server and one the client. After the STA module establishes WiFi connection to the AP module, and the client connects to the server, then the bidirectional serial link should be open.

author: roboteux
author_rank: Contributor
timestamp: January 26, 2024, 02:33:01 pm
content: thanks I'll give that a try

author: Tinkerer5096
author_rank: Newbie
timestamp: June 12, 2025, 06:28:40 am
content: Hi macboy. Would you be able to be a little more specific on the setup of each module? When logged in to the webserver of the modules there are a number of settings/options, which ones are necessary and which are optional and why?Cheers mateSimmo
DTMF input to the MT8870 IC - Page 1
Forum section: electronics / projects

author: Siddhat
author_rank: Regular Contributor
timestamp: September 08, 2019, 10:29:58 am
content: Hey, I am currently working on a project based on Dual Tone Multi Frequency (DTMF) and have used a MT8870DE IC to decode the DTMF tones. Referring to the datasheet I connected the circuit diagram as prescribed but I am having problems regarding DTMF input to the IC. The input was given using a head phone jack by connecting the 3.5 mm jack to the mobile phone and the other end to the DTMF input of the IC. But how do I know which wire to connect to the input of the IC as there are 4 or sometimes 3 wires of the jack. Anyone?Here is the datasheet attached that I preferred.

author: Richard Crowley
author_rank: Super Contributor
timestamp: September 08, 2019, 11:04:31 am
content: Use a 3-terminal connector ("TRS").Do not use a 4-terminal connector ("TRRS")That way you will not have to decode which is the ground/return node.It will always be the "sleeve" ("S") terminal.Then use the "tip" ("T") for your audio signal.That will always be the "left" channel of the stereo audio.In the case of a voice call, the left/tip and ring/right will be the same (i.e. "monaural")But it is probably not a good idea to connect the tip/left directly to the ring/right terminal.
DTX question (Ethernet wire testing) - Page 1
Forum section: electronics / projects

author: dima-m
author_rank: Newbie
timestamp: August 04, 2020, 06:47:22 am
content: i had dtx done on a 4-wire etherent cable and received a split pair error....; not sure if this definitely means that connector is miswiredalso, not sure why is insertion loss so high on pairs 4/5 and 7/8 when it is only a 4-wire setup; dtx is setup for 100base-t...attached is a pdf of results, if anyone want's to take a look and give their opinion

author: Whales
author_rank: Super Contributor
timestamp: August 04, 2020, 07:52:46 am
content: Never used such equipment, so I can only guess.QuoteThe 100base-t setting probably still tests those pairs. They are sometimes used (eg when people split the one cable into two and run two 100Mbit links over it)High insertion loss == wire doesn't exist. Makes sense.QuoteLooks like it (EDIT: or it's a badly/non twisted cable). Both ends too, so the same person has done both. Have a look at the order of the coloured wires that have been punched down or crimped.Without knowing more about the equipment: all of its results may be useless if the pairs are split.Does it come with a manual?
dual audio inputs to speaker - Page 1
Forum section: electronics / projects

author: kk4lgt
author_rank: Newbie
timestamp: October 06, 2023, 06:19:15 pm
content: Hello,I have a redio that outputs two separate outputs, one for upper sideband and on for lower sideband. Would a diode in each output to the speaker keep them isolated and allow it to work. The outputs are only used one at a time, not simultaniously.Thanks Stan/kk4lgt

author: fourfathom
author_rank: Super Contributor
timestamp: October 06, 2023, 06:37:31 pm
content: No, diodes will cause terrible distortion (I used to put a diode in my guitar amplifier output as a cheap fuzzbox). Do these outputs drive a speaker directly? If not, you can use a resistive combiner between the outputs and the amplifier, say a 100 Ohm resistor in series with each output, then connected together at the amplifier input. Even if the radio outputs each drive their own speaker (?) you can try using 10 Ohm resistors for the combiner, and there should be no ill effects. Make sure the resistors can handle the power though.What kind of radio has separate USB and LSB outputs? Never heard of this, and don't understand why you would want to combine those outputs.

author: kk4lgt
author_rank: Newbie
timestamp: October 06, 2023, 09:27:23 pm
content: Thank you for your help. The radio is a r-1051b /urr receiver from the USN. The speaker output is 60ohm and I have a 60 to 8 ohm transformer on the lsb output right now feeding a small amp. Looking not to spend the money for another 60 to 8 ohm transformer and amp for usb.

author: TimFox
author_rank: Super Contributor
timestamp: October 06, 2023, 09:35:12 pm
content: Seehttps://antiqueairwaves.com/nlee/r-1051_index.html"USB" and "LSB" refer to the upper and lower sideband of a surpressed-carrier AM transmission."SSB", commonly used by amateur radio operators and others, uses one or the other of the two sidebands around a (missing) carrier frequency.The two 600 ohm outputs on the back can be used for the two channels in the "ISB" (independent sideband) mode with different information on the two sidebands.https://en.wikipedia.org/wiki/Independent_sideband.Note that the two audio outputs are 600 ohm, not 60 ohm.600 ohms is a common impedance level for audio line outputs.
Dual band WiFi module at less than <$5 - Page 1
Forum section: electronics / projects

author: sangar
author_rank: Regular Contributor
timestamp: January 10, 2019, 06:04:55 am
content: Hi All,I am looking for a wifi module which is around $5...I have looked in TI and others like AMPAK (Chinese manufacturer), they are near to $10...So, if anyone came across those WiFi modules, please suggest...Thanks,Muthu

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 10, 2019, 03:53:59 pm
content: Take a look at ESP32 modules. You'll get an MCU as a bonus.

author: pix3l
author_rank: Regular Contributor
timestamp: January 10, 2019, 04:19:28 pm
content: ESP32 only does 2.4GHz WiFi right? OP asked for dual band..

author: blackbrayn
author_rank: Contributor
timestamp: January 10, 2019, 05:44:08 pm
content: Indeed , ESP32 offers only 2.4ghz b/g/n connectivity.
dual base transistor? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: November 22, 2024, 08:07:49 am
content: I found a dual gate MOS transistor. Ok, it looks interesting to play with one day.Dual gate transistors look to be mainly RF type devices.But I wondered if it has a counterpart, i.e. a Dual base transistor.the symbol exists on german wikipedia

author: IconicPCB
author_rank: Super Contributor
timestamp: November 22, 2024, 08:33:22 am
content: Dual gate fet is actually a cascode kind of structure where the lower transistor drain drives the source of the upper device typically used in RF work. The BJT equivalent is similarly structured such that the lower discrete transistor drives the emitter of the upper transistor.Upper transistor operates in common base configuration and presents a low impedance load to the lower device minimising deleterious effects of Miller capacitance. I have not come across a dual base cascode single package device.

author: guenthert
author_rank: Frequent Contributor
timestamp: November 22, 2024, 08:46:29 am
content: Well not quite a dual-base transistor and won't match the given symbol, but there are (or were) unijunction transistors (e.g. 2N2646).

author: Kleinstein
author_rank: Super Contributor
timestamp: November 22, 2024, 08:49:33 am
content: I also have not seen cascode connected dual BJTs as the equivalent to a dual gate MOSFETs. There are JFET+BJT hybrids however.Inside ICs there are also dual emitter/collector transistors, with the emitter or collector split to different parts. These were used in some TTL gates and are used for current mirrors. I have not seem them as discrete parts.

author: coppercone2
author_rank: Super Contributor
timestamp: November 22, 2024, 08:59:58 am
content: I thought they were like this.

author: voltsandjolts
author_rank: Unknown
timestamp: November 22, 2024, 09:22:59 am
content: Note the internal connection between gate 1 and gate 2 in your second picture, which just makes a standard fet, with improved characteristics.

author: coppercone2
author_rank: Super Contributor
timestamp: November 22, 2024, 09:46:11 am
content: Oh I thought it was more clear, but I think they have isolated ones? Or are all the isolated ones cascode structure?I only found it interesting because I thought they had separate drivers
Dual Channel Power Supply 1 or 2 Bridge Rectifiers? - Page 1
Forum section: electronics / projects

author: dave_robinson_022
author_rank: Contributor
timestamp: February 07, 2022, 06:01:05 am
content: I am building a 2 channel supply and want to use a switch to enable higher voltage or current.I have BU1208 bridge rectifiers which can handle 12 Amps.Am I better switching before rectification and saving a bridge rectifier and smoothing capacitor or leaving it as shown?

author: bob91343
author_rank: Super Contributor
timestamp: February 07, 2022, 06:10:24 am
content: There are several reasons you might pick one option over the other. Efficiency, component stress, cost, and a few others. So it depends on your priorities.

author: geggi1
author_rank: Frequent Contributor
timestamp: February 07, 2022, 06:36:48 am
content: If you go for two separate rectifiers and voltage regulators you can have two independant voltages.The benefit of this is that some electronics require two diffrent voltages.You can also run balanzed voltages like +/-12V, +/-5V and others.There are very few integrated voltage regulators is desigend for up to 50V.Finaly think about the heat that have to be radiated from the heat sink if you run 5V and 6A with a 50V supply (50-5)*6=270W.

author: dave_robinson_022
author_rank: Contributor
timestamp: February 07, 2022, 06:54:36 am
content: I should have clarified that I am using it for a bench power supply.The transformer has two windings each at 25v 6A. I will use software control to ensure that channels do not exceed current capacity.This is a one off unit and I have 3 capacitors and a few bridge rectifiers so cost is not an issue

author: Ian.M
author_rank: Super Contributor
timestamp: February 07, 2022, 08:05:22 am
content: Two independent floating channels supplied by separate secondaries is the generally preferred configuration, especially if it can be configured with the channels in series for more voltage or symmetrical supplies, and in parallel for more current, with one master channel controlling both, but if the slave channel enters current limiting in a series configuration, the master output voltage (not voltage setpoint) should also reduce to maintain symmetry.Any other approach requires each channel to have twice the current capacity to cope with paralleled secondaries, twice the voltage rating to cope with series secondaries and double the heatsinking. This may make sense as a cost-saving measure for a single channel supply due to the top right corner of the output stage SOA being basically 'lopped off' at DC, but is less desirable in a multi-channel supply.

author: not1xor1
author_rank: Frequent Contributor
timestamp: February 07, 2022, 08:11:36 am
content: Quote from: dave_robinson_022 on February 07, 2022, 06:01:05 amthe pseudo schematic connections are wrong (e.g. bridge rectifier)apart from that you'd better build 2 completely separated power supplies and then use their output in series, parallel or independently like all existing 2 channel PSUsNote:transformers specified VA value is for a resistive load only. When you use a rectifier + capacitors you have do derate the maximum current value.
Dual channel USB wifi Card, Can someone tell me what these RF pieces/parts are? - Page 1
Forum section: electronics / projects

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: July 10, 2015, 03:51:55 pm
content: Ok I have a dual channel USB wifi n card which I would like to add custom antennas too and I know the copper on the top is the ground part of the antenna and the center pole is under the solder mask. Im thinking it would be easiest to remove the shielding can and tap the antenna directly to the chip after cutting the traces but I was curious what these little things are called and what they do, I have an idea they may have something to do with a to d conversion but i am not sure.

author: jwm_
author_rank: Frequent Contributor
timestamp: July 10, 2015, 05:02:18 pm
content: Those are the external antenna sockets. You definitely don't want to cut traces, it's all impedance matched. just plug your antennas into those sockets.I'm not sure exactly which those are, maybe hirose u.fl meant for something like thishttp://www.amazon.com/Laptop-Wireless-PCI-E-Internal-Antenna/dp/B004ZHT2JE
Dual diode TO-220, 8A 1200V - finding alternative - Page 1
Forum section: electronics / projects

author: gaminn
author_rank: Frequent Contributor
timestamp: November 24, 2023, 02:59:37 pm
content: Hi,I'm looking for DSP8-12A diode, two 8A 1200V diodes in series in TO-220 package, they call the configuration "phase-leg". It is only available from Newark and Farnell, but they have very high shipping costs. I would pay like 40 bucks for 4 diodes.Anybody knows any alternative part? I've already spent an hour searching for it with no luck...

author: sprint
author_rank: Newbie
timestamp: November 24, 2023, 05:01:39 pm
content: https://www.rsonline.cn/web/c/semiconductors/discrete-semiconductors/schottky-diodes-rectifiers/?searchTerm=dSP8-12A&redirect-relevancy-data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://www.mouser.cn/c/?q=DSP8-12Aor CHINA TAOBAOhttps://detail.tmall.com/item.htm?abbucket=5&id=740251084021&ns=1&spm=a21n57.1.0.0.5150523cxYZJEUThe Last Resort：Bridge Rectifier，AC pin only use 1.

author: gaminn
author_rank: Frequent Contributor
timestamp: November 24, 2023, 05:19:20 pm
content: Thank you so much. I searched for the diode using octoparthttps://octopart.com/search?q=dsp8-12a&currency=USD&specs=0, it displayed RS has some in stock but I swear it always opened this itemhttps://uk.rs-online.com/web/p/schottky-diodes-rectifiers/9200694?searchId=8ab50fea-d8dc-41dd-aef1-fcbe8f18258d&gb=swhich is not in stock. I don't understand it, but I'm glad I can now order.