ATMEGA32 ICSP programming - Page 1
Forum section: electronics / beginners

author: xitenik
author_rank: Newbie
timestamp: November 21, 2017, 03:49:54 pm
content: Hello guys. I am new to programming. I have this MiniPro TL866a programmer and I wanted to use the ICSP port to read a chip. I was comparing the icsp pins on the board and these given in internet and the programmer, but something doesn't look right.I need to read this Atmega32a AU chip, but I don't want to do something stupid and erase it by mistake, so I need an advice.There are few things that I think are messed up. First, it doesn't fit any pinout in the internet. Second , the vcc pin is disconnected. Is that normal ? Where the chip will get power to be red ?Could you please tell me what to do , so I can read it properly , without erasing.Thanks!

author: imidis
author_rank: Frequent Contributor
timestamp: November 21, 2017, 04:23:30 pm
content: This is my guess, I would probe the one to vcc see if thats vcc, the empty pads look like a spot for a pull up on the reset pin. But be careful not to put more voltage than the board was designed for. (VCC GND may be reversed if top layer is vcc)It's very possible the chip fuses are set so it will not be able to be read

author: Arjen_Arg
author_rank: Contributor
timestamp: November 21, 2017, 05:39:45 pm
content: imidis is right, the only question would be VDD as he says, but the rest matches the datasheet perfectly.

author: xitenik
author_rank: Newbie
timestamp: November 21, 2017, 09:10:03 pm
content: So I measured some things on the board. The NC , where the VCC is supposed to be, is not connected to anything. When the power is connected to the board, on the right pad the voltage is 4.77, and the left pad is 4.65V. The right pad with 4.77 is connected to the power of the board, but it is NOT connected to the VCC pin of the ICSP.I don't know what is pull up resistor. Should I try reading the chip , without VCC ? Or to try and read it , when powered on?

author: imidis
author_rank: Frequent Contributor
timestamp: November 22, 2017, 06:47:53 am
content: If you just connect ths MISO,MOSI, RST and SCK to the TL866 ICSP and use the board power to power up the chip you can see if you get any comunication from it.

author: xitenik
author_rank: Newbie
timestamp: November 22, 2017, 08:03:24 am
content: Ok, so I managed to read the data, but this is what it showed. Does these settings mean, I can't read the chip?

author: cowana
author_rank: Frequent Contributor
timestamp: November 22, 2017, 08:58:52 am
content: QuoteSource:https://electronics.stackexchange.com/questions/53282/protecting-avr-flash-from-reading-through-isp, user 'Garrett Fogerlie'

author: xitenik
author_rank: Newbie
timestamp: November 22, 2017, 09:27:31 am
content: Thanks for the quick reply.If I desolder the chip and read it with the programmer, will it give me the same results, or I will be able to modify then?

author: cowana
author_rank: Frequent Contributor
timestamp: November 22, 2017, 09:31:15 am
content: Regardless of whether the chip is on the board or not, it's not going to be possible to read out the firmware.Unfortunately your best bet would be reverse engineering it and writing it from scratch if you need to change something.