Help finding out what this chip is? - Page 1
Forum section: electronics / beginners

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 11:32:54 am
content: Hey everyone, I am hoping someone might have some luck finding out what this chip is, it's a small 8 pin smd package. I first thought it was some eeprom, but the pins are connected in a weird way for that. My phone won't take a good pic but the logo looks like either PI or AI, not really sure, the chip has the two following bits of text on it.j24CO2-S11311Tpins 1-4 are all connected and that leads to the four main buttons on the device, pin 5 seems to be connected on the pother side of two 222 resistors in parallel (these are SMD, so I'm guessing that's 222 ohms?), and pin 8 is connected before those, but these are also on the same decenly large trace going to the buttons, there are three traces coming out from under it, two directly go to the blob covering the chip on board and one is jumpered across to a bunch of other stuff.I'm guessing this is some type of mosfet, since I've never seen any transistors in an 8 pin package on dave's teardowns.

author: Flipp
author_rank: Contributor
timestamp: January 04, 2014, 11:36:02 am
content: Its a good old 24C02 I2C EEPROM!http://www.atmel.com/Images/doc0180.pdfPin 1-4 are the grounded adress inputs.The Resistors are Pullups for the I2C lines and the other big trace is VCC. SCL an SDA are going under the blob. Write Protect is often not used at all.Flip

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 11:48:54 am
content: Quote from: Flipp on January 04, 2014, 11:36:02 amAh cool so I was right, neat. I'm gonna see if there is a way I can read it with my arduino mega or something and maybe I can modify something in it to add a feature, who knows, I've never bothered to try lol.Thanks.

author: Flipp
author_rank: Contributor
timestamp: January 04, 2014, 12:04:23 pm
content: Let us know what Device it is!

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 12:12:58 pm
content: Quote from: Flipp on January 04, 2014, 12:04:23 pmIt's this power meter, it works pretty good but it lacks the options another one I have seen reviewed does, it still works great though, I've wanted to get more into dumping eeprom chips and maybe finding ways to modify how the devices run instead of just modifying the hardware, no clue where to start on that though, but there are probably some ways to do it with an arduino.http://www.ebay.ca/itm/121174419231?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

author: amyk
author_rank: Super Contributor
timestamp: January 04, 2014, 12:19:48 pm
content: First result of "j24c02" is the datasheet for your IC:http://www.szjzsic.com/htmledit/UploadFiles/2011426142427710.pdf(Product page ishere. And according to that page, apparently the manufacturer is an "ELECTRCNIC TECH CO.")And post some pictures if you want help with the rest of your project.

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 12:30:29 pm
content: Quote from: amyk on January 04, 2014, 12:19:48 pmI think once I find a tutorial on dumping the eeprom with my arduino (if I can) it will just be a matter of working on the actual code, or whatever they put out, (I think it's all in bytes from 0 to 255 or something?). Wish I had some old tech with a DIP eeprom to practice on. I probably won't get to it for a long time.And besides, you know you can't trust anything electronic unless it comes from ELECTRCNIC TECH CO, they are of course one of the most famous in the industry for reliable and high quality parts

author: garak
author_rank: Contributor
timestamp: January 04, 2014, 01:21:36 pm
content: The contents of the EEPROM are highly unlikely to be executable code. It'll mostly just be configuration settings, calibration data, logs etc. Without having some frame of reference (a second device, or the source code for instance) figuring out what the bytes on the EEPROM do will be very difficult, if not impossible. Best of luck, though! Your Arduino should definitely be able to dump the contents.

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 01:25:48 pm
content: Quote from: garak on January 04, 2014, 01:21:36 pmah, alright, well, should be interesting to poke at anyways, I'm guessing it stores the power cost setting and usage then as it has a small rechargeable battery to keep that stuff active.

author: XOIIO
author_rank: Super Contributor
timestamp: January 04, 2014, 01:40:30 pm
content: Alright so I guess somehow I got the wrong reading on those resistors, the one from IN - is a 100 ohm, the one from in+ is a 300 ohm.I've checked on the side of in+ and between the two resistors but there is no connection to the IN HI pin (31) on the chip, IN LO (30) on the chip is connected though

author: JOERGG
author_rank: Contributor
timestamp: January 04, 2014, 03:44:27 pm
content: Quote from: XOIIO on January 04, 2014, 11:32:54 amA 3 digit resistor code on a smd reads the first 2 digits directly and the 3 digit is a multiplier ten upon that digit or the number of following zeros. 222 means 22*10^2222= 2200 Ohms or 2.2 KOhms.A look on the E-Table may show you, if your guessed value is a possible existing value.http://www.logwell.com/tech/components/resistor_values.html