Help needed in recognizing MCU (with picture)! - Page 1
Forum section: electronics / general

author: Fliz
author_rank: Contributor
timestamp: November 27, 2012, 03:27:29 pm
content: Hi all,I would need help in recognizing MCU that I took out from my bike light.It's a cheap chinese light but it does a really good job, only downside are the modes in which this light can work.So, I decided to change them but for that I have to reprogram MCU unfortunately all markings from top side of MCU were deletedat the bottom there is only this code:123SNAZ0Band some hieroglyphs that I cannot decipher!!!Pictures attached:Please, help, anyone!!!

author: alanb
author_rank: Frequent Contributor
timestamp: November 27, 2012, 05:09:38 pm
content: Not all MCUs are reprogrammable. If you were able to identify the chip and assuming that it is re programmable and had the correct programmer for it would still be a major challenge to re write the firmware without access to the original source code.As an alternative you may be able to reverse engineer the PCB to get a schematic, then find an MCU with the correct pin outs and then write the firmware from scratch.This would also be quite difficult to do.Sorry I don't have a simple solution.

author: TheDirty
author_rank: Frequent Contributor
timestamp: November 27, 2012, 05:46:43 pm
content: Looks like pins 1 and 8 are VDD and VSS, so it looks like an 8pin PIC would work. MCLR would have to be disabled. It looks like it's being pulled down. Everything would have to be checked on the board, but it looks like a good possibility.

author: T4P
author_rank: Super Contributor
timestamp: November 27, 2012, 05:47:09 pm
content: It's highly probably a PIC or a AVR

author: jabramo
author_rank: Regular Contributor
timestamp: November 27, 2012, 06:01:52 pm
content: ^^ I doubt it.This thing will have been cost cut to the max. AVR and PIC are defiantly not the cheapest so my guess it isn't one of the two. I think alanb is right I doubt it will be reprogrammable. I would guess this thing would have something similar in it as the MCU that electric toothbrush Dave took apart once.You might be lucky to retrofit a PIC in there like TheDirty says

author: T4P
author_rank: Super Contributor
timestamp: November 27, 2012, 06:09:14 pm
content: You doubt it but chinese flashlights come with either ARM or PIC, what else can you find a SO-8 package?

author: Fliz
author_rank: Contributor
timestamp: November 27, 2012, 06:13:08 pm
content: I know that all but (referring to aalanbpost) I was still hoping to be able to reprogram the damn thing because it's much easier to do that (if it's not locked) then to unsolder original mcu and solder back the replacement... Original source code is not so important because I don't like it anyway.As for reverse engineering: MSP430G2230 from Texas Instruments has a compatible pinout (datasheet, page 2), my friend (with same bike light) got one today, burned new UI to it and replaced original MCU with it, works better than the genuine MCU BUT, it's a pain in the "back" to do so and it can only be done once (soldering that thing is messy job), that's why I was hoping to discover what is the genuine MCU and I was hoping it's Attiny (something like 13a) only question in that case would be is it locked or not...CheersP.S. P4T is right, chinese flashlights mostly use atmel atiny13a:

author: amyk
author_rank: Super Contributor
timestamp: November 27, 2012, 06:17:40 pm
content: What happened to R10?The circuit looks simple enough to trace, and finding the positions of the power supply pins will get you a good idea of what the MCU is. Fortunately AVR and PIC have different pinouts. If all else fails a decap will give you exactly the model/make, as that is written on the die.

author: Fliz
author_rank: Contributor
timestamp: November 27, 2012, 06:22:37 pm
content: Quote from: amyk on November 27, 2012, 06:17:40 pmclose encounter with hot soldering ironGuess who wonDoes this look familiar to you AVR/PIC guys?

author: Fliz
author_rank: Contributor
timestamp: November 27, 2012, 06:35:50 pm
content: PIC12F683 maybe???For now, it's working OK with that TI MCU solution...