hybridfree/eevblog-posts huggingface dataset:
PIC ADC loading my circuit? - Page 1
Forum section: electronics / projects

author: dreaquil
author_rank: Regular Contributor
timestamp: February 08, 2015, 05:15:24 pm
content: So I'm trying to read from a current sensor with a range of -5A to 5A. This gives a voltage of 1.5V to 3.5V respectively with 0A being at 2.5V. I'm amplifying this around 2.5V in order to get a full range of 0V to 5V for -5A to 5A so that I meet my ADC's maximum input voltage. I'm using the SAR ADC on my pic18f45k50 to read this. I realised that when my ADC was connected to the output of U3A, the voltage was being pulled up to 2.9V when the current was 0A (the output should have been 2.5V). In order to work around this I placed a 75ohm resistor to ground cause I figured the ADC was pulling up the voltage and this partially solved it until the current begins increasing negatively and reaches a current of about -2.88A. Then the ADC begins clamping the voltage again and doesn't let me get an accurate reading. I set ANSELB =1, TRISB=1 and turned off the weak pull up resistor but the same problem is still occuring. Any ideas as to whats causing it?

author: Skimask
author_rank: Super Contributor
timestamp: February 08, 2015, 05:21:40 pm
content: A) Forget the amp, just use the 1.5v-3.5v signal, get that working. Buffer the output of the current sensor of course, but forget trying to get 0-5v.B) The LM324 won't pull to ground. RTFDS.C) Profit?

author: dreaquil
author_rank: Regular Contributor
timestamp: February 08, 2015, 05:30:41 pm
content: the 1.5 to 3.5V is working fine...but i'd really like it to be 0 to 5V and the output of the 324 should be able to go down to 0Vhttp://www.ti.com/lit/ds/symlink/lm124-n.pdfPage 7 (Vol). Must be profit :/PS I'm sure its the ADC causing it cause when I read the voltage without the ADC connected to it, it functions fine.

author: dreaquil
author_rank: Regular Contributor
timestamp: February 08, 2015, 08:29:54 pm
content: Turns out it was some setting in my code.

author: Skimask
author_rank: Super Contributor
timestamp: February 08, 2015, 09:38:19 pm
content: Quote from: dreaquil on February 08, 2015, 05:30:41 pmDOH...not sure what I was thinking of then...
PIC development board suggestions - Page 1
Forum section: electronics / projects

author: Lucky-Luka
author_rank: Unknown
timestamp: December 22, 2020, 05:54:14 pm
content: Hi allI am thinking about designing a PIC development board similar to this one:https://www.rhydolabz.com/development-boards-development-boards-c-206_99/pic18f4580-development-board-mini-rhydolabz-p-1928.htmlI was thinking about 12V 3A power supply for it like this one:https://www.amazon.com/Chanzon-Switching-Adapter-100-240V-Transformer/dp/B07HNV6SBJ/ref=sr_1_3?dchild=1&keywords=power+supply+12v+3a&qid=1608659328&sr=8-3I would like to design a motor driver board to complete this kind of demo board. I was thinking about dc brushed motor and servo motor that usually work at 5-6V and stepper motor at 12V.What do you think the power part should look like?Maybe a buck converte 12v-6v and a low dropout regulator to power the PIC and other peripherals at 5V?The power part of the aforementioned board I think is not the best solution...https://www.rhydolabz.com/documents/SCH-0226%20Schematic1.pdfAny suggestions will be greatly apreciated.Regards
PIC -> or gates -> LCD ? - Page 1
Forum section: electronics / projects

author: SilverHawk
author_rank: Contributor
timestamp: March 19, 2016, 02:26:29 pm
content: Im having trouble understanding why are the (or gates) necessary ?, does it have to do with delay ?

author: Buriedcode
author_rank: Super Contributor
timestamp: March 19, 2016, 02:34:06 pm
content: Its a terrible diagram.I can only assume that because the LCD is powered by 3.3V and the PIC is 5V that the OR gates are used as level translators a 74LVC32 is a quad OR gate chip for 1.2-3.6V operation that has 5v-tolerant inputs. So the logic and LCD are powered by 3.3V, with the PIC at 5V. The pull-down resistors are too low value. 2.2k with 5V across it means they'll be using up 5/2200 = ~2.3mA each when the line is high. I would change those to 22k or 10k as all they are doing is acting as pull downs for logic.If you're powering you micro with 3.3V (if the chip works at that voltage) then you can get away without the logic.

author: SilverHawk
author_rank: Contributor
timestamp: March 19, 2016, 02:36:05 pm
content: sorry about that , its the only 1 i have
pic port amplify - Page 1
Forum section: electronics / projects

author: gatoulisss
author_rank: Contributor
timestamp: February 05, 2015, 01:36:46 pm
content: hello guys!!i have a question.im using pic 16f88 connected to some sensors and a buzzer its like an alarm, my question is can i amplify the output of the pin witch is connected to the buzzer so i can have much louder sound? (the sound driver is the pic so the buzzer is not making any sound if i just connect it to a battey) for example the port output is +5v can i make it +9 and how?thank you very much!

author: johm
author_rank: Contributor
timestamp: February 05, 2015, 02:29:47 pm
content: One of your solutions is using an off the shelf NPN transistor (2n2222, 2n3904, BC548, etc.) wired like this:An NPN Transistor behaves like a current switch / current amplifier. The higher current any output pin of the PIC16F88 can sink/source is 25mA, as in pg. 161http://ww1.microchip.com/downloads/en/DeviceDoc/30487D.pdfso this will allow a higher current to flow from the collector to the emitter of the transistor resulting in louder sound.In case you don't understand something, feel free to ask.Regards,Johm

author: gatoulisss
author_rank: Contributor
timestamp: February 05, 2015, 02:50:42 pm
content: i tried with bc547 transistor and it works on some buzzers but in this type is nothttp://www.ebay.com/itm/231141835644?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITany idea?and is there any way to amplify the buzzer using a transformer? and how i can make the connections?

author: johm
author_rank: Contributor
timestamp: February 05, 2015, 03:29:56 pm
content: Using a transformer is an overkill, what's more, you'll have to add a DC voltage for the buzzer to work. Have you got the datasheet for this particular buzzer? Take a look at its impedance and operating voltage.

author: gatoulisss
author_rank: Contributor
timestamp: February 05, 2015, 04:17:20 pm
content: i had the buzzer of the foto and is loud as i want to be and it use an transformer... so i think that using transformer in the ones i got would give me the loudness i want. so how i can make this?
PIC Pro Mini breakout for most SO-28 PIC16's (and hopefully more) - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: May 12, 2015, 04:06:41 pm
content: As I have told you I have a bunch of PIC16F72 and this breakout hopefully broke all pins out in appropriate ways. I will spin a few of those boards (with my VoltCard Original) and if it worked I will open source it for you.PICKit connector on the left, using straight pins up. Crystal on the right, I will probably use 16, 20 or 24MHz.

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 12, 2015, 04:13:08 pm
content: Would be a good idea to route the xtal tracks without the vias. It will still work, its just not best practice.

author: technix
author_rank: Super Contributor
timestamp: May 12, 2015, 04:17:14 pm
content: Quote from: bookaboo on May 12, 2015, 04:13:08 pmWell that works but breaks ground plane. I run GND on top and VCC on bottom.

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 12, 2015, 09:46:31 pm
content: You would be better with GND on the bottom, VCC and signals on top.

author: technix
author_rank: Super Contributor
timestamp: May 12, 2015, 09:49:40 pm
content: Quote from: bookaboo on May 12, 2015, 09:46:31 pmUsed to do that until the ground vias drove me crazy. Now I am usually GND on top VCC on bottom.

author: technix
author_rank: Super Contributor
timestamp: May 12, 2015, 10:08:57 pm
content: Quote from: bookaboo on May 12, 2015, 09:46:31 pmActually on this board I figured out a way to put GND on both sides and do a lot of GND via stitching, and extra thick power tracks.
PIC programmer - Page 1
Forum section: electronics / projects

author: yalect
author_rank: Regular Contributor
timestamp: October 22, 2015, 08:16:42 am
content: Hello,can I build simple PIC32MX220 programmer works with PC Port RS232?thanks

author: KL27x
author_rank: Super Contributor
timestamp: October 22, 2015, 09:41:11 am
content: You have to find a programming software that supports that part. I have used IC Prog and PIC pgm, but that specific part doesn't appear to be supported. Search around and maybe you will find something.OTOH, if you are ok with using a USB port, you can build any number of PK2 clones. There are some that are greatly "watered down." But you will need to program the PIC 2550 using, say, a JDM programmer. That's a long way to go to save a few bucks.
PIC Programming Question - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: March 07, 2022, 01:47:18 am
content: I have a Superpro 280U programmer which supports a PIC I want to (hopefully) read the code from and burn a blank: PIC12CE67XPage 28 of the manual (see attached) states that DIP chips are inserted at the bottom. If a chip has a special connection, when the chip is selected in the software, it will pop up with a pin connection.The PIC is 8 pins, but this programmer doesn't label any pins nor show a diagram for the pin connections. Before I insert it into the programmer, I want to make sure I don't blow up the chip.Does the programmer determine how to set the pin states? I don't understand how the programmer would figure out that pin 1 is VDD and not a data line.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 07, 2022, 03:04:03 am
content: Any programmer ive seen start from the bottom socketex:pins 17 18 19 20 - 21 22 23 24 40 pins socket andpins 19 20 21 22 - 23 24 25 26 for the 44 pins socketnormally the programmer will do some tests and it should not damage an blank chip

author: bostonman
author_rank: Super Contributor
timestamp: March 07, 2022, 03:19:57 am
content: Should I buy a blank first and run a test, or will it not prove anything because it's blank?So this looks like a 48 pin socket on the programmer. I should stick the 8 pin PIC on the very bottom (so pin 4 of the PIC will be in pin 24 on the programmer socket?

author: jiarui
author_rank: Contributor
timestamp: March 07, 2022, 09:00:25 pm
content: I'm not sure if you need to modify, write code. But a Pic Kit 3 is very handy. You can get a clone for around $20. You'll need to connect 5 pins, including ground and power between the chip and the kit. You can also use it to debug code.

author: bostonman
author_rank: Super Contributor
timestamp: March 08, 2022, 02:07:29 am
content: Thanks for the advice.I had looked into buying one before starting this thread, but then discovered the programmer I have supports this model PIC.
PIC PWM Calculators - Page 1
Forum section: electronics / projects

author: HeyTom
author_rank: Contributor
timestamp: September 16, 2013, 03:26:16 pm
content: I have some PIC PWM Calculators you might find useful.http://micro.alleypress.org/Say, for example, your pic is running a 8Mhz and you need a PWM frequency between 2000 and 3000 Hz, but you want to have as many bits of resolution as possible. The third calculator will create a chart for that. Then, click on a row to get duty cycle calculations.There's also one that gives you the minimum and maximum frequencies based on pic speed.These also work on a smart phone browser.

author: John steave
author_rank: Newbie
timestamp: October 06, 2013, 05:27:51 pm
content: I think your idea is very good and you may go forward perhaps I suggest you to visit the linkhttp://actpcb.com/pcb-calculatorwhere you can get enough knowledge about calculator.Thanks!!!
PIC silicon bugs - ADC offset - Page 1
Forum section: electronics / projects

author: armandas
author_rank: Frequent Contributor
timestamp: November 05, 2010, 10:36:36 pm
content: I was looking for a high pin-count PIC and one good looking option was thePIC18F66K22. It's a very capable device, yet costs only £2.99 in single quantities. I thought I was lucky, until I checked theSilicon Errataand found this:QuoteADC is vital for my project and now I'm puzzled. Has anyone dealt with ADC offsets? I could use the suggested workaround if the same offset applies to all the channels (dedicating one channel for automatic calibration). The other option would be to buy a separate SPI ADC, but that results in extra costs.Also, what does 50 LSB mean if the ADC resolution is 12 bits?P.S. Selecting different device doesn't seem to be an option. All reasonably-priced chips belong to the same family and non-K equivalents are about twice as expensive (plus got other silicon bugs).

author: Simon
author_rank: Unknown
timestamp: November 06, 2010, 01:10:48 am
content: I think they are trying to say that the error may be of 50 (maximum reading is 4096), so a converted number could be offset by 50. the channels usually use the same ADC that is switched from channel to channel

author: allanw
author_rank: Frequent Contributor
timestamp: November 06, 2010, 05:28:23 am
content: 1 LSB = 2^(-12) * Vref

author: armandas
author_rank: Frequent Contributor
timestamp: November 06, 2010, 09:46:10 am
content: Thanks for the replies, it makes sense now.
PIC SIMON, PIC16F84 - Page 1
Forum section: electronics / projects

author: Mr J
author_rank: Regular Contributor
timestamp: February 01, 2013, 03:26:28 am
content: Got PIC Simon up and running today for the students project, love my jobhttp://www.n1ir.com/2013/01/pic-simon.html

author: Mr J
author_rank: Regular Contributor
timestamp: February 04, 2013, 07:07:27 pm
content: just milled the PCB, check out the pic and video
PIC used as very inexpensive ARM debugger - Page 1
Forum section: electronics / projects

author: majbthrd
author_rank: Contributor
timestamp: January 23, 2014, 09:00:17 pm
content: Here is a personal project that I've been working on which might be of interest.I wanted to see what was feasible in the way of a very-low-cost ARM board. OK, that doesn't sound original, but stick with me.The solutions that I've seen (Tweeny, McHck, mbed, etc.) are limited to wholesale firmware updates. Press a button, download a new image, and see if it works.I wanted to implement an integrated CMSIS-DAP debugger (ARM standard that is compatible with multiple OSes). That way, one can do everything from flash updates to single-step debugging.The brute-force solution would be to plop two ARMs on a board, where one has USB capability and acts as the debugger.However, that gets pricey. Atmel, for example, is using an AVR32 on their Xplained boards in a debugger role to shave costs, but the AVR32 isn't exactly a dirt cheap chip either.Instead, what I did was use a PIC... a PIC16F1454 to be precise. It costs $1.25US in single quantity and goes below a US dollar in 1k+ quantity. Plus, it doesn't need an oscillator (further lowering total BOM costs).The firmware solution consists of two halves.The first is a USB bootloader that also doubles as a USB-to-UART bridge (thereby also saving the cost of a FTDI chip or equivalent).I've published the code (including patches to the Microchip USB Framework) here:https://code.google.com/p/pic16f1454-bootloader/The bootloader lets one download an application into the second half of the PIC's flash.For a sample app, I've managed to write a CMSIS-DAP implementation that fits entirely in 4kwords of the PIC16F1454's memory.One of the ARM targets that I've tested it with is a NXP LPC812 (Cortex-M0+), which is a another <$1US CPU.So, with two $1 chips, a USB connector, an LDO, and some passives, one has a complete development board with integrated debugger.I've attached a picture of a sample PCB I did through OSH Park.

author: dannyf
author_rank: Super Contributor
timestamp: January 23, 2014, 09:11:36 pm
content: Worthy efforts.There is also a Russian implementation of jlink on STM32F chips, in case you are interested.jlink-ob itself is quite simple as well.
PIC16F877a using switching power supply - Page 1
Forum section: electronics / projects

author: mukulkhairatkar
author_rank: Contributor
timestamp: July 15, 2010, 11:00:24 pm
content: Hello All,Anybody has idea about how to power up PIC16F877A using a 5V Switching power supply? I have a 24VDC switching power supply and L4976 step down regulator, I could step down the voltage but it does not power up PICAny suggestions??Thanks

author: EEVblog
author_rank: Unknown
timestamp: July 16, 2010, 12:25:18 am
content: The PIC is rated to work at 5V, so if you 5V rail is stable it should work. There must be some other issue with startup/programming of the PIC.Is the oscillator working? Any pin activity?Dave.

author: DavidDLC
author_rank: Frequent Contributor
timestamp: July 16, 2010, 01:35:03 am
content: I have been using PIC18F2455 with a small SMPS, it's a wall USB phone charger.I have been programming it, using USB communication, serial communication with no problems so far.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 16, 2010, 03:07:08 am
content: DMM da Vo wil ya? n err.... da Io?

author: mukulkhairatkar
author_rank: Contributor
timestamp: July 16, 2010, 04:08:01 pm
content: Yup...Solved...My configuration bits were wrong.....I choose XT instead of HS...Thanks GuysMAK

author: TechGuy
author_rank: Regular Contributor
timestamp: July 26, 2010, 10:19:27 pm
content: Quote from: mukulkhairatkar on July 16, 2010, 04:08:01 pmI use Buck Regulators such as the LM2476 . I did run into an issue with instability until I added a Pi filter to reduce the switching noise.
PIC18F ADC measuring 0 during runtime - Page 1
Forum section: electronics / projects

author: lmagalhaes
author_rank: Contributor
timestamp: August 27, 2022, 10:40:51 am
content: Hi there,I have a custom board with a PIC18F47Q84, some relays and thyristors, NTC inputs and some other circuitry. The relays are controlling electrovalves and pumps, while the thyristors are controlling thermoblocks.When the program starts running, everything is fine, the microcontroller can accurately read the NTC inputs and control the temperature of the water with the thyristors with no issues. However, during the operation of the machine, activating the electrovalves and pumps etc, the PIC stops reading the NTCs correctly, always reading 0 or very low voltages (adc values below 10 out of 4095). I can check this behaviour during debug (with a PICKIT4 connected and a debug session on MPLAB) and a soft reset to the beggning of the program makes the ADC read correctly again. There's no resets on the micro, no brownouts, it doesn't start over or jump to any weird parts of the program, it just reads 0 on the ADC ... I have checked all the registers pertaining to the configuration of the ADC to see if anything changes when it starts reading 0, but everything stays the same. I have also checked the PMD3 register which enables the ADC module and that's fine. I have checked the TRISx, LATx, ANSELx registers and they all have the same information as in the beggining of the program.I did check the 5V rail with an oscilloscope and it has a lot of ringing, but if that was the problem wouldn't the micro just brownout or reset altogether ? The board is powered by a transformer (230VAC to 12VAC, 15VA), going to a full bridge rectifier and a 2200uF electrolytic cap. This rail then goes to the coils of the relays and to the input of a switching voltage regulator that brings the voltage down to 5V. The thyristors are being driven by an optocoupler (MOC3022) and the coils have a reverse biased diode and have a NPN serving as the switch to ground. I have taken this all out and put a power supply generating the 12V for the board, but the same issue persists. I have been going at this problem for days now and can't figure out what is the problem with it. We have a pretty similar board, same relays, same thyristors, same driving method for both, same input power block, just a smaller transformer, pretty much the same circuit, but with an Atmega328 instead of this PIC. I choose the PIC because it was cheaper and was pretty much superior in all aspects, but it's giving me this issue...Can someone help me understand what is happening?
PIC18F Software Problems - Page 1
Forum section: electronics / projects

author: House91320
author_rank: Regular Contributor
timestamp: December 21, 2010, 11:17:51 pm
content: I'm trying to create USB data acquisition device with a PIC18F4550 and my friend and I are having a real hard time getting the software side of it to work. Does anyone know of a good tutorial that can explain the following?Which bootloader to use?Should we use the HID bootloader, and if so, how do we get it to work?

author: Gary Servin
author_rank: Unknown
timestamp: December 22, 2010, 02:34:21 am
content: What compiler are you using?? Microchip's Application Library comes with a Bootloader project for MPLAB C18.

author: House91320
author_rank: Regular Contributor
timestamp: December 22, 2010, 02:53:56 am
content: maybe i should explane more, pc recognizes the pic and the HID driver woks but beyond that we are stuck what, i would like to get to the point where i can turn leds on with the computer. any one got any ideas?

author: Gary Servin
author_rank: Unknown
timestamp: December 22, 2010, 03:14:52 am
content: Depends on which compiler you are using. Here's an article I found when I started with USB on PICs. But they use Hi-Tech compiler.http://www.waitingforfriday.com/index.php/Building_a_PIC18F_USB_device

author: metalphreak
author_rank: Frequent Contributor
timestamp: December 27, 2010, 02:59:03 pm
content: The bootloader is only for loading a new program onto the PIC via USB. It has nothing to do with communicating with a host device.If you download the USB framework from microchip's website, there are plenty of examples. The easiest way to implement a basic device is to use their framework that enumerates the PIC as a Serial Port on the host PC. Then its pretty easy to use serial communication for control/data transfer. There's even an example app for turning LEDs on and off with all the Visual Basic projects/code included.The HID bootloader takes up 0x1000 space while the MCHPUSB/PICDEM bootloader only uses 0x0800. However, you need to install specific drivers on the host PC to use MCHPUSB. The HID bootloader is plug and play.There is also a HID driverless framework for communication as well but its a bit more complicated to use.

author: migsantiago
author_rank: Frequent Contributor
timestamp: December 27, 2010, 06:15:41 pm
content: Bootloaders sometimes interfere with the main program on the PIC. The configuration bits that are fixed for the bootloader may not be compatible with the configuration bits that the main program is relying on.That's why I never use bootloaders. I'd recommend that you buy an external programmer so that you don't get any misconfigurations.
PIC18F45K50 Dev Board  - Page 1
Forum section: electronics / projects

author: Luis Estrada
author_rank: Contributor
timestamp: July 25, 2020, 10:53:22 pm
content: Hello All,My name is Luis, I am brand new to the eevlog forum, and I was looking to have y'all look over my design of a PIC18F development board. I have been working on this project for about 9 months with mixed success, I have designed 5 different prototype PCB's and only two have worked :/ . Below I attached my latest design, I look forward to your critique.PCB Info:- Made with KiCad- Two layer boardLuis

author: NivagSwerdna
author_rank: Super Contributor
timestamp: July 25, 2020, 11:13:25 pm
content: Hi Luis,Well I like the PICKIT3 edge connector, nicely laid out and a 90 degree header would work well.I would change the USB-A for Micro USB-BAlso... if you can just go for SMD components; it's so much easier once you get the hang of it.Welcome!Nivag

author: Luis Estrada
author_rank: Contributor
timestamp: July 25, 2020, 11:18:04 pm
content: Thank you! For the feed back!Luis
PIC18F870 controlled fanbus project - Page 1
Forum section: electronics / projects

author: Wayneo
author_rank: Contributor
timestamp: July 11, 2010, 04:18:50 am
content: Hi all, Found a project that looks pretty good, take a look and see what you thinkEnjoy!!Wayne.http://www.electro-tech-online.com/electronic-projects/40835-pic18f870-controlled-fanbus.html

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 13, 2010, 06:56:30 pm
content: A fan speed control without temperature feedback is not very useful. A good one should also include speed feedback, and the best can even sense torque to determine static pressure. All of which are easy to implement in a microcontroller.

author: Wayneo
author_rank: Contributor
timestamp: July 16, 2010, 11:50:33 pm
content: Quote from: NiHaoMike on July 13, 2010, 06:56:30 pmHi NiHaoMike, That would be a much better idea, I've been looking around at peoples ideas like the one above, I agree its pretty basic but good for beginners rite? What I would like to learn is how to write the controller language (it looks more complex than DOS programs lol)Im new to microcontrolers but my Uncle has just given me the Z80 and the MK14 programmer kits (old but somewhere to start)I take it the language works the same for modern microcontrollers or is it more complex?I have got HEX Editor NEO, Eagle, All the programs For the PICkit 2 is that enough for me to start Writing the software?The other week I sucessfully made my first PIC Project LCD to USB using the PIC18F2550 I was well chuffed!Basic I know but its a start! he heIf you come across some good ideas on the fan controller projects could you let me know please? I'd be very greatfull Thankyou.Wayne.Me Needs More Input

author: NiHaoMike
author_rank: Super Contributor
timestamp: July 17, 2010, 01:52:39 am
content: I actually tore down a small ECM fan motor a few days ago. Unfortunately, the construction is such that the board broke into several pieces when taken apart. There's a 4001, 358, and PIC12F508, along with two MOSFETs, a few unidentified SMD ICs, and lots of SMD discrete components. From what I can tell, the 358 conditions the resolver signal and detects overcurrent, the 4001 drives the MOSFETs, and the SMD ICs are responsible for generating the PIC Vcc from the 12v input and performing level translation. The PIC monitors the resolver signal to perform closed loop speed control, check the current to protect the motor from overloading, modulate the MOSFET drive signals, and communicate over a 2 wire serial bus of some sort. It defaults to full speed if power is applied with the communication lines disconnected. I never figured out the serial interface so I don't know exactly what it is capable of.The actual fault seems to be a shorted MOSFET, probably from thermal fatigue or some other circuit fault. I have built a simple discrete drive circuit to run the still-usable motor and it actually spins the motor faster than with the original circuit, but it vibrates a lot. Clearly, the PIC actually PWMs the drive signal to reduce vibrations that would result from simple square wave drive.
PIC24 doing OCR for Bingo balls - Page 1
Forum section: electronics / projects

author: voja
author_rank: Contributor
timestamp: February 04, 2015, 01:09:38 am
content: I made this project five years ago, and now I started from scratch to do it seriously. It is PIC24 based controller which locates and recognizes Bingo ball numbers. Sampling + processing time is about 450 ms, and the error rate is hardly mesureable close to zero. Described athttp://www.voja.rs/PROJECTS/ocr/ocr_0.htm

author: glatocha
author_rank: Regular Contributor
timestamp: February 04, 2015, 07:04:26 am
content: This looks like a very cool project. And a lot of image manipulation software have to be written.Good job!

author: 22swg
author_rank: Frequent Contributor
timestamp: February 04, 2015, 10:11:55 am
content: My project grey cells are buzzing, working with same pic now , can you give camera details pls.

author: Howardlong
author_rank: Super Contributor
timestamp: February 04, 2015, 10:43:57 am
content: Indeed, quite an achievement for a PIC24.

author: voja
author_rank: Contributor
timestamp: February 04, 2015, 11:25:14 am
content: Quote from: 22swg on February 04, 2015, 10:11:55 amIt's the low cost TV camera, B&W or color, with 12V supply. I took it from some surveillance dome. It is recommended to use the higher focal length, so that the bigger area of the ball is covered. Then you shall have less problems with bad ball angular positioning, when all numbers on the ball are far from the center of the image.

author: 22swg
author_rank: Frequent Contributor
timestamp: February 04, 2015, 08:28:17 pm
content: Thanks voja, Not for bingo but small stuff identification... have ordered a OV7670... (not the same but it was low cost ).... can't wait to play...

author: givaracom
author_rank: Newbie
timestamp: August 03, 2015, 05:29:15 am
content: we are a professional bingo machines factory and we are looking for a complete ocr bingo balls system ( ball reader) if anybody can help for that issue please to contact us as soon as possibleemail : givaracom@yahoo.com

author: jagrane
author_rank: Newbie
timestamp: September 04, 2016, 09:17:05 pm
content: Dear Sir VojaI am interested in buying some units of your project (OCR for Bingo balls).How I can I contact you?jagranevb @ yahoo. esjagrane @ terra. com

author: ebclr
author_rank: Super Contributor
timestamp: September 05, 2016, 09:22:39 am
content: Congratulation, nice project. It's worth include on my bookmark

author: mpicker21
author_rank: Contributor
timestamp: September 05, 2016, 01:29:47 pm
content: This is sweet. Thanks for the detailed explanation on the site. I collect golf balls along a golf course and thought it would be cool to make some crazy device that washes them and sorts them by brand automatically. It's still way beyond my ability but your write up gets my geers turning. It would be really difficult though due to the crazy variations in golf balls and logos or scuff marks.Anyways, thanks for the awesome share.
PIC24 pin problem - Page 1
Forum section: electronics / projects

author: MrCrit
author_rank: Newbie
timestamp: March 03, 2015, 10:50:52 am
content: Hi,I've got a PIC24FJ64GB004 running tons of LEDs. However, pin 22 is sitting at 15 ohms above ground and I'm not sure why. I lifted the pin itself off the pad and it's definitely something in the chip. The other functions on that pin are:PGEC1 - I've configured it to use PGEC2 so this shouldn't affect itAN3 - I've turned off the analogue inputsC2INA - Comparator InputDMH - USB, I haven't enabled itRP1 - Peripheral, shouldn't affect itPMD1 - Parallel Master Port DataCN5 - Interrupt on change, Not configuredI'm an apprentice so go easy on me if it's just a dead pinThanks guys.

author: dannyf
author_rank: Super Contributor
timestamp: March 03, 2015, 11:49:34 am
content: QuoteI am sure you meant something by that but it may not be clear to others.

author: 22swg
author_rank: Frequent Contributor
timestamp: March 03, 2015, 12:10:34 pm
content: Without looking at the DS does it have pull up / pull downs ? 15 ohms ?PIC apprentice ...

author: Unknown
author_rank: Unknown
timestamp: March 03, 2015, 03:17:00 pm
content: Are you sure pin 22 is configured as output?Check all the pin registers and read the errata.

author: hans
author_rank: Super Contributor
timestamp: March 03, 2015, 04:51:27 pm
content: Are you measuring the resistance when off? If so, the software setting have nothing to do.If not, I would only expect any meaningful measurement when the pin is an input or open drain.If you lifted the pin and it's measuring 15 ohms to GND, it's most likely a dead pin.

author: Howardlong
author_rank: Super Contributor
timestamp: March 03, 2015, 05:03:46 pm
content: Yes we need to know what "pin 22 sitting at 15 ohms above ground" means and how you're measuring it, in circuit or out of circuit, with or without power applied, etc etc.

author: voja
author_rank: Contributor
timestamp: March 03, 2015, 06:39:07 pm
content: Do you use it as input or as outut? General purpose or what?Can you attach the initialization part of code here?Maybe you put some unintentional value in RPOR0? Check indirect addressed writes.Is the rest of MCU working ok?

author: atferrari
author_rank: Frequent Contributor
timestamp: March 03, 2015, 07:40:03 pm
content: Do you have a twin to see if it repeats the behavior?
PIC24FJ256DA210 + Graphical LCD + Ethernet = Google Map demo :) - Page 1
Forum section: electronics / projects

author: johnmx
author_rank: Frequent Contributor
timestamp: September 23, 2012, 08:26:15 pm
content: Since I have a bunch of used but working LCDs, I made a small (but dense) control board in order to use them in my future projects.In this video you can see the Google Map demo running in my board.The original firmware can be found in the Microchip Libraries of Applications. I adapted the firmware to work with my board and use the AR1020 touch screen controller.

author: richcj10
author_rank: Unknown
timestamp: September 24, 2012, 01:13:23 am
content: Nice work!Could I see a schematic?It looks very interesting!Regards,Rick

author: johnmx
author_rank: Frequent Contributor
timestamp: September 24, 2012, 09:48:53 am
content: The schematic is the same as the “PIC24FJ256DA210 Development Board”. The only difference is the LCD power supply which is specific to this LCD model.Most of my work was to design such small PCB only in double layer. I took several days to do it.Microchip Webpage:http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en547641
PIC24HJ128GP506 How to program Blinkey? - Page 1
Forum section: electronics / projects

author: tru3533
author_rank: Regular Contributor
timestamp: July 24, 2023, 04:45:43 am
content: Got hold of a tray with PIC24HJ128GP506, and got very optimistic about this grate opportunity to learn some C code and programming a PIC MCU.Installed MPLAB X IDE v6.05 (latest support for Pickit 3, that I have)First bummer MCU is to old for MCC support, so no automatic pin configuration.Then I started to look for getting started documentation, example code, etc, but I can't seem to find any.Do you have any idea where to find?

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2023, 02:50:38 pm
content: I mean... did you even bother to look on the product page?Right onhttps://www.microchip.com/en-us/product/PIC24HJ128GP506#document-table(admittedly, under "documentation" which is a bit wrong), they have code examples to download. They're projects for the old MPLAB, which in theory you should be able to import into MPLAB X, but you may consider just installing the old MPLAB to verify that it can be set up correctly for your chip.With that said, I certainly wouldn't use that chip if you're quite new to C programming. Configuring MCUs by hand is a pain in the butt, so a fully-supported dev board (like Arduino, ESP32, STM Nucleo, etc.) is probably a better place to start. Or at least a PIC that's supported by MCC. My very first exposure to anything PIC was on a board I designed (boss told me to use an 8-bit PIC so I chose one with peripherals that matched my application well) using the PIC16F18857. It worked perfectly, and with MCC getting it up and running was not hard at all. All the same, without some prior microcontroller experience (mostly Arduino and ESP32 under Arduino, plus some STM32), it would have been harder, since you still need to understand what it is you're configuring, even if it is done visually!
PIC32 - Programmer needed - Page 1
Forum section: electronics / projects

author: AMyatt
author_rank: Contributor
timestamp: September 17, 2014, 12:41:54 am
content: Hello,I have a project I am working on with a PIC32MX (basically a web accessible temperature sensor, relay & digital input device). Unfortunately due to work commitments I find myself with no time to write the firmware for this project (I'm new to PIC and this level of complexity, so 90% of my time would be spent doing research).I'm looking for someone to write the firmware with the following features:* Serve webpages from an external 32Mbit flash, these pages will display and control the temperature sensors, relays and digital inputs.* Firmware upgrade via webpage (upload of hex file and loading to internal program flash).* Sending of email based on inputs.More information can be provided upon request.I'm happy to pay for your services.- Anthony
PIC32MZ ADC Touchscreen ISR problem - Page 1
Forum section: electronics / projects

author: MaTech
author_rank: Newbie
timestamp: July 29, 2018, 04:29:30 pm
content: I'm currently working on getting a 4-Wire resistive touchscreen to work with MPLAB X v4.20 and harmony v2.06.Hardware wise I have a Pic32MZ2025DAH176 on a Custom Board and This screen (Datasheet:http://cdn-reichelt.de/documents/datenblatt/A500/ET0350G0DH6.pdf).X+ (Pin 30, An14) and Y+ (Pin 8, AN8) have both a 100K Pullup.X- (Pin 9) Y- (Pin 10)I configured Harmony after an example from aria_quickstart (pic32mz_ef_sk_s1d_pictail_wqvga), but I only get -1 back from my ADC in DRV_TOUCH_ADC_Tasks().Has anyone experience in doing this?Thanks in advanceEdit:I was able to narrow my problem down and it seems like it hast something to do with the ISR which is calling DRV_TOUCH_ADC_PositionDetect();.In DRV_TOUCH_ADC_PositionDetect(); the ADC values are read and, because the ISR which should be called by a Timer is not functioning correctly I only get the default value of -1.I've attached some pictures of my Harmony configuration for the Timer and Touch Drivers and the ISR in drv_touch_adc.c.
Pick and place machine with mechanical tweezers? - Page 1
Forum section: electronics / projects

author: VermontEE
author_rank: Contributor
timestamp: September 21, 2016, 02:39:12 pm
content: Does anybody know of a pick and place machine that is equipped with mechanical tweezers?I have to pick 4.5x4.5x0.7mm pieces of glass off of backing tape. The glass has been diced from a wafer and needs to be transferred to a tray. This is the perfect job for a SMT pick and place robot. But I cannot use a vacuum pickup, the silicone tip will mark the glass, This is a non-negotiable requirement, no vacuum pick up.If you know of existing equipment or old equipment that got replaced by vacuum equipment, please let me know.Thanks

author: Ijaz
author_rank: Contributor
timestamp: September 21, 2016, 05:03:35 pm
content: Samsung has been offering machines (e.g. SM451) with what they call a gripper nozzle. They mainly use it for mounting AV connectors on TV boards.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 22, 2016, 07:46:11 am
content: A mechanical tweezer seems more likely to mark than a vacuum pickup - what about a teflon nozzle ?
Picking an op amp for uA to A current sensing circuit and reverse protection - Page 1
Forum section: electronics / projects

author: i509VCB
author_rank: Contributor
timestamp: December 05, 2024, 10:54:52 pm
content: A few questions for my current sensing circuit. The main reason for this to exist is sampling current draw from a microcontroller and the surrounding circuits. The high sample rate requirement is for looking at current draw as the microcontroller wakes up and goes to sleep. There is also an ARM CMSIS-DAP debugger and JTAG scan support and a very crappy logic analyzer but these are irrelevant to the discussion here.Some specifications:1uA to 2A measurement range (switching sense resistors with some mosfets - based on the circuit here:https://www.eevblog.com/forum/projects/reducing-effect-of-rdson-in-mosfets-when-sensing-currents-above-1a/msg5721605/#msg5721605)100mV max drop across sense resistorCommon mode voltage of at least 5V. I would definitely like higher if possibleNeeds to survive reverse connection. Pretty much if I take the + and - lines connected to the DUT and swap the two there should be no magic smoke.Can also act as a power source (switching converter behind a mosfet on the high side).Ideally a 500MSPs sample rate. I can compromise a bit on this, but mainly because I suspect that I'm hitting the limits of USB FS. It would be great of course if I could get to 1MSPs.Sample using a microcontroller's ADC.A set of "calibration" resistors that I can switch in to compensate for offset voltages.First the ADC. I am likely to use the RP2040 which has an enob of 8.6. However its not guaranteed to be the final part in the case that I would like USB HS (some STM32). If I do end up keeping the RP2040 then I might end up using an external ADC or something like an MSPM0G310 for a "smart" ADC to get to 10 bits.First question picking an op amp? I have looked at some instrumentation amplifiers but find a lot of these are expensive and have some less than ideal bandwidth. At the same time because I am lazy I would like a part which has a high common mode voltage above 5V. I am tempted to add a gain of 10 as well to make the ADC go a bit further but I would need an instrumentation amp then. A 2nd stage programmable gain is probably another option.If I can't find a suitable part with a high enough common mode voltage, then what options are available for increasing this while not messing up the current measurements?A question relating to reverse protection: using a diode is probably a bad idea due to the voltage drop. Some sort of mosfet on the input and output of the sensing I think would stop backwards current flow (which I already need for the power source and to isolate output when using the calibration resistors.
Picking apart a load management terminal - Page 1
Forum section: electronics / projects

author: metertech58761
author_rank: Frequent Contributor
timestamp: April 21, 2025, 04:13:43 am
content: I've been looking at this schematic that I reverse-engineered of an old load-management terminal and I would like some help gleaning some information on its design.Panel A:This section consists of the front-end receiver and three different timers (Deadman, Blink, and Outage)What I'm after:Confirmation that the RC constant of the Outage section is ~90 secondsWhere does the blink detector end and the deadman / reset begin?Is there a time constant with the 'blink' detector or does it just work with voltage levels (i.e., could it theoretically be replaced with a voltage supervisor IC - i.e., MAX706)?Panel B:This section is the output driver and amplifier.What I'm after:As it sits, does the 170V rectifier "contaminate" the ground level? I tried taking some readings on one of these board sets a while back with AC applied only to get nipped when touching the low-voltage DC ground.Panel D:This is where the power / signal connections and the external interface connector enter the unit.What I'm after:U20 section - what is the benefit of using a comparator for an input versus an optoisolator? All four inputs are activated by grounding the corresponding pin.U21 section - what seems to be its purpose? I have a hunch it relates to an off-board ADC daughterboard (unfortunately, that daughterboard is impossible to find today and this load management terminal was obsoleted 30+ years ago, so no factory documentation remains).Panel C:Just including it for completeness, but one header, J3, I believe also goes to the aforementioned daughterboard?
pickit2 - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: October 20, 2013, 11:38:04 am
content: I used my pickit2 to program PIC microcontroller , but after programmed when I plugged it into the circuit it wouldn't work correctly. When I programmed the PIC with Enable code protect option it work correctly.please tell me weather the PIC have to program with protection enable or not or else please tell me what is the correct procedure.

author: Alana
author_rank: Frequent Contributor
timestamp: October 20, 2013, 12:51:28 pm
content: Interesting thing - when i was doing DCC decoders for model railway one out of 5 pics i used acted funny - programmed and verified OK but failed to work in a circut. Sounds like your problem and possibly a faulty chip.

author: mariush
author_rank: Super Contributor
timestamp: October 20, 2013, 02:30:38 pm
content: Is it really THAT hard to carefully READ THE DATASHEET of the PIC chip and UNDERSTAND what the "code protect" feature does?Or how about reading the Pickit2 manual?
pickit3 - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: June 18, 2015, 12:12:27 pm
content: Hi guys ,I like to purchase pickit3 but while searching in web I found that pickit3 is priced around $50 in farnell , mouser but in aliexpress it is starting from around $14 , why it is such big difference , does this cheep Chinese one have gunine parts . can I buy this from aliexpress, please guide

author: McBryce
author_rank: Super Contributor
timestamp: June 18, 2015, 12:45:31 pm
content: The Aliexpress one is a cheap knock-off, not an original Microchip product.Bryce.

author: Kalvin
author_rank: Super Contributor
timestamp: June 18, 2015, 12:54:29 pm
content: I have used this one successfully in my hobby projects with the PIC24F32KA-series controllers:http://www.ebay.com/itm/Clone-Microchip-Development-Programmer-Mini-PICKIT-3-/350637699036About half of the price compared to Farnell/Digikey with free shipping. I also have a genuine Pickit 3from Microchip at my office and I haven't noticed any difference.

author: picandmix
author_rank: Frequent Contributor
timestamp: June 18, 2015, 08:21:56 pm
content: Also bought a China Pk3 in a red case like those shown in AliExpress; also no problems so far.Suggest you pay a couple more dollars and get the ones with the Zif socket board, very handy.
pico-ps2-sniffer - Page 1
Forum section: electronics / projects

author: dreg
author_rank: Newbie
timestamp: January 07, 2025, 08:27:44 am
content: Physical PS2 keylogger using a Raspberry Pi Pico (pico-ps2-sniffer)https://github.com/therealdreg/pico-ps2-sniffer

author: dreg
author_rank: Newbie
timestamp: January 07, 2025, 09:37:01 am
content: Creating a real-world PS2-keylogger has been challenging and is still in beta. Take a look at some adapters on Amazon: they produce a peculiar long CLOCK signal each time, along with short pulses before the actual packet.The PIO code must be compatible with these kinds of signals. Although the protocol should follow the standard and theoretically shouldn’t matter, unexpected behaviors occur in real-world scenarios.Additionally, I found adapters that intermittently emit short pulses of various types, featuring fast rise and fall edges.I am attaching some images.

author: dreg
author_rank: Newbie
timestamp: January 07, 2025, 02:19:57 pm
content: Another PS2 to USB Adapter from Aliexpress with a fast 1.8us low pulse (CLOCK LINE).These types of 'glitches' do not impact the functionality of the PS2 keyboard or the adapter in any way, but they do present a problem when developing a generic sniffer.
pico-usb-sniffer-lite - Page 1
Forum section: electronics / projects

author: dreg
author_rank: Newbie
timestamp: January 05, 2025, 11:49:05 am
content: Some USBPcap + Wireshark setups fall short. So here the pico-usb-sniffer-lite project, a USB sniffer for LOW SPEED & FULL SPEED. It can be used as a physical keylogger: Raspberry Pi Pico + a few materials (~10$). Thx Alex Taradov (@ataradov) (usb-sniffer-lite):https://github.com/therealdreg/pico-usb-sniffer-lite/I have ported everything (PIO+SRC) to pio-sdk and made some changes. It won't be exactly the same as the bare-metal version.

author: voltsandjolts
author_rank: Unknown
timestamp: January 05, 2025, 01:58:49 pm
content: Alex's original thread:https://www.eevblog.com/forum/projects/usb-sniffer-using-rp2040/

author: dreg
author_rank: Newbie
timestamp: January 05, 2025, 03:17:42 pm
content: Thx! added to readme