Help reading an EEPROM - Page 1
Forum section: electronics / beginners

author: jbryan189
author_rank: Contributor
timestamp: May 23, 2023, 02:07:47 am
content: I have newbie project of reading a STMicroelectronics 4256BWP IC, which is like a 24C32.I have PonyProg to use to gather the information as well as a XP laptop.I've seen all kinds of cables made to do this task. One that interests me is the DB-9 and the wires go directly to the chip with micro grabbers. Others have pull up resistors and decouple capacitors.Any direction of my project is greatly appreciated.

author: darkspr1te
author_rank: Frequent Contributor
timestamp: May 23, 2023, 07:24:04 am
content: Quote from: jbryan189 onTodayat 04:07:47 am>https://www.ebay.co.uk/itm/133737699365?hash=item1f23635825:g:XnYAAOSwUHxjkptA&amdata=enc%3AAQAIAAAA8DcTYR2Df9gOvxzu5oy4XzcnhX%2Bxhv3KIb7Sr4CnqCQK38VhMMM9m5f56%2FBxgsutqcgyVhhYNNXbTY4j40F9JKP16zVtxHw81S67keT99otwMIf48prk2ZVP2j9%2BIiqKtV3GJAeEZ%2FFXU2BSzrRGsFiC1Jog8grOs%2FkuhSMbn1frgHg9p22EvBVUb%2Fonf%2BivJDoFMQF5ITYnLmP6pgYyVqlaYMhkehxWMDje1scGmU79%2BeDPhqnpNYe7lMJ5GkYmAD9%2BDYuUnkWZEnbyFIuadjpVm47H6gOjB9mClmQObP6X3ThNlLBqd%2FKFBUAXzFlf9Q%3D%3D%7Ctkp%3ABFBM9Ivg94hi

author: coromonadalix
author_rank: Super Contributor
timestamp: May 23, 2023, 12:50:44 pm
content: @ Darksprite your ebay link is way too long, always stop after the interrogation symbol xxxxxxxx?Pony prog normally have the pinout on their page, the problem(s) you may face: is somethime the read / write pin could be physically tied to a ground or a positive voltage, sometimes you can read but not write ... or circuitry need to be powered on and put into a continous reset for the mcu to be able to read and write ....if it doesn't work, you have to remove it and put it into a programmer with a proper tests socket

author: barshatriplee
author_rank: Regular Contributor
timestamp: May 23, 2023, 02:28:19 pm
content: I think you can use an universal programmer.

author: jbryan189
author_rank: Contributor
timestamp: May 28, 2023, 02:22:02 am
content: Thanks for the replies!Im going to get a Bus Pirate on order.I think I'll have to remove the chip and try it with out the board possibly interfering with my testing (trying).Seems easy enough and i'll keep the forum postedThanks again for the answers and support for the new guy.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 28, 2023, 11:49:48 am
content: you have ch340 341 based programmers with sockets for very low prices .... really cheap lollon some sale you have the normal soic size and the wider soic size sockets includedcheck their supported ic's list

author: jbryan189
author_rank: Contributor
timestamp: May 28, 2023, 01:00:58 pm
content: Thanks as I ordered one of them also.Just a bit nervous getting my feet wet in this new adventure. Been always wondering how things work and figured this would be a fun way.appreciate the forum help. Hope to continue relies soon as I get the Bus Bandit!John

author: rstofer
author_rank: Super Contributor
timestamp: May 28, 2023, 02:16:42 pm
content: This Sparkfun document might be helpful:https://learn.sparkfun.com/tutorials/bus-pirate-v36a-hookup-guide/allIt's regrettable that after 15 years, Python projects are still using version 2.7ETA:If you have a Raspberry Pi, this might be worth considering:https://learn.adafruit.com/adafruits-raspberry-pi-lesson-4-gpio-setup/configuring-i2cOr for the Arduino:https://learn.adafruit.com/adafruit-24lc32-i2c-eeprom-breakout-32kbit-4-kb/arduinoThis is a nice "Starter Kit" for the Raspberry Pihttps://www.amazon.com/FREENOVE-Ultimate-Raspberry-558-Page-Detailed/dp/B06W54L7B5And the Pi 4https://www.amazon.com/Raspberry-Pi-Computer-Suitable-Workstation/dp/B0899VXM8FOr the Pi 400https://www.amazon.com/Raspberry-Pi-Quad-Core-Bluetooth-Complete/dp/B08XS24CMVThis is a nice platform for use as a development machine and a general purpose Linux workstation.The Arduino UNO Starter Kit is also quite good:https://www.amazon.com/ELEGOO-Project-Tutorial-Controller-Projects/dp/B01D8KOZF4Or the Mega version:https://www.amazon.com/EL-KIT-008-Project-Complete-Ultimate-TUTORIAL/dp/B01EWNUUUAAll of the Starter Kits have projects involving I2C

author: radiolistener
author_rank: Super Contributor
timestamp: May 28, 2023, 07:29:01 pm
content: You can use Chinese programming clamps to read/write it without desoldering:https://www.aliexpress.com/item/32966553440.html

author: darkspr1te
author_rank: Frequent Contributor
timestamp: May 29, 2023, 09:40:05 am
content: Quote from: radiolistener onYesterdayat 09:29:01 pm

author: jbryan189
author_rank: Contributor
timestamp: May 29, 2023, 04:15:07 pm
content: Thanks for the links.I have exhausted maypole of Pi, but have a Arduino left. I have it running a little web server shield app.I'm going to try to use the clamp method first as quickly as I get my Bus Pirate. I'm hopeful that I can just do it this way but have a friend with a solder station w hot air I can use. I ordered some flux along with the Bus Pirate.Appreciate the help!

author: jasonRF
author_rank: Regular Contributor
timestamp: May 29, 2023, 06:54:34 pm
content: I recently had to do this for the first time (for an eeprom in a picoscope) and I left the chip on the board, using minigrabbers to connect to the soic8 chip legs. I don’t have any wisdom, beyond reminding you to make sure you understand all of the voltage levels involved. I used an arduino, but had to use a simple logic voltage level converter for the 5v arduino to safely interface with the 3.3v logic on the board. Take your time and don’t rush it.Jason

author: jbryan189
author_rank: Contributor
timestamp: May 30, 2023, 12:38:16 am
content: Thanks, as I think this is the easiest way for me also. I received the clamp and it hits the board connection and appears to be close but not exactly the fit I'd hope for.I have my Arduino and looking into using it to read this. (Love to have a new Pi, but not for $150 USD and 4 month delivery.)Thank you for the input as this new adventure unfolds.

author: rstofer
author_rank: Super Contributor
timestamp: May 30, 2023, 02:38:50 pm
content: Quote from: jbryan189 on May 30, 2023, 12:38:16 amI don't know where you live but here in California, delivery for a Pi 4 is 2 dayshttps://www.amazon.com/Raspberry-Pi-Computer-Suitable-Workstation/dp/B0899VXM8FThere are 3.3V Arduinos but the official Arduino is 5V. You can convert a 5V Arduino to 3.3V by changing the voltage regulator and adding a diode. I would just buy a 3.3V Arduino:https://learn.adafruit.com/arduino-tips-tricks-and-techniques/3-3v-conversionI don't know whether you need 3.3V or 5V, you'll have to figure that out.Of course it is the same problem with the Pi in reverse.. It is 3.3V and not 5V tolerant. There are numerous articles on Google about dealing with 5V external logic.See if the memory chip is 3.3V or 5V then decide how to proceed. If 5V, use standard Arduino. If 3.3V, I would use a Raspberry Pi but a 3.3V Arduino is workable (if it really is 3.3V).

author: jasonRF
author_rank: Regular Contributor
timestamp: June 01, 2023, 11:32:35 pm
content: I essentially used the bjt-based level shifter circuit herehttps://www.eevblog.com/forum/beginners/mosfet-as-a-level-shifter-i-dont-understand/msg3808184/#msg3808184when connecting my 5v rduino to a 3.3V eeprom on the board (that also had an fpga on that 3.3v rail). I used different values for a couple of parts (10k for R2 and 100pF for C1), but it doesn't seem super sensitive to that. Of course I tested the level shifter before hooking it up to the eeprom.jason

author: jbryan189
author_rank: Contributor
timestamp: June 02, 2023, 01:22:30 am
content: According to the data sheet,https://www.st.com/en/memories/m24256-bw.htmlit will do 2.5 to 5.5 vdc. Plan to reassemble it and verify voltage and pins for correct before I do any of the "magic".Bus Bandit is going to be here Saturday, but thinking about the Adruino possibility also. (We all like a good tinker)I assume the bus bandit and PonyProg will figure out the address automatically, I hope anyways. I have a unformatted .bin file for the chip to do some comparison to.

author: jbryan189
author_rank: Contributor
timestamp: June 23, 2023, 02:21:08 pm
content: Finally got it all connected after checking the wiring about 70 times.I tried to get the exchange going with the Bus Pirate and the Pony Program and it give me a "Are the connections correct" error.I have not verified the 3.3 volts from the Bus Pirate board, I plan to look later this evening. I have noted in my scouring the internet of people say to not use the onboard 3.3 within the BP. Some never mention it.Just a quick update for the forum as the adventure has begun.JohnUPDATE:I have verified the 3.3v on the physical board, but when I measure the pins going to the chip itself I get nothing. Looking to see if I can get the 3.3v from the test point to the Bus Pirate 8 pin header.

author: jbryan189
author_rank: Contributor
timestamp: June 25, 2023, 07:34:56 pm
content: Appears my Pony Prog isn't doable with my Bus Pirate. Appears I'' have to either make the Lancos interface, which appears pretty simple.I'm going to try to do the Command line method first using Putty or some terminal program. Anyone have a cheat sheet for tis method?Is there another recommended GUI for the new guy someone can recommend?When I get it working/talking, how do I save the read I just completed?Appreciate the forums help!John

author: jbryan189
author_rank: Contributor
timestamp: June 26, 2023, 01:38:53 pm
content: I was able to get the Bus Pirate to operate last night with a "overcurrent error".I can assume I'll need to lift the VCC leg off or remove the chip entireity? Can I inject the power using a battery pack to get me 3 volts? The Bus Pitate has a 150 mA capacity.I am quite nervous about the desoldering at this point in my adventure.

author: jasonRF
author_rank: Regular Contributor
timestamp: June 26, 2023, 04:48:51 pm
content: I am not knowledgeable enough to know about your specific error (or even to know what a “pony prog” is). But if the product reads the contents of the eeprom itself (say at startup), then you may be able to extract the contents just by monitoring and decoding the serial lines using a logic analyzer or scope with serial decoding. I have done this in the past as well, and should have mentioned it in my first reply.Jason

author: darkspr1te
author_rank: Frequent Contributor
timestamp: June 28, 2023, 06:55:17 am
content: use flashprog instead of ponyprog for bus pirate support.darkspr1te

author: jbryan189
author_rank: Contributor
timestamp: July 05, 2023, 02:50:39 am
content: Thanks.I am planning to either lift the power leg or remove the chip entirely this week.Stay tuned as the adventure continues.Appreciate all the help!John