DIY ATmega BMS (followup to DIY Arduino BMS)


Aug 9, 2019
This is a followup for an old thread, which was blocked due to inavtivity:
Here is the Link to the old thread.

Another little step is done:

I just testet the first Atmega328 chips. With the help of some Arduino boards (I had a Atmega2560 and a Duemilanove compatible board which is equiped with a Atmega328) I was able to burn bootloaders on the chips and test them with the simple blink test-program on a breadboard. I thus now have the evidence, that I am able to go ahead with the bare Atmega328 chips. I had them working with 3.3v and so far no problems.

I used a DIYMORE AVR ISP shield on the ATMEGA2560 to burn the bootloader on the bare chips.
I used theMiniCorebootloader, which supports internal clock use and brown-out-detection.*
Then I used the Duemilanove with removed Atmega-chip to upload software using thesetup described hereand tested with blink program

I think at least a 100nf capacitor over pins 7 & 8 of the chipwould be mandatory for later use (also possibly a 100k pullup for the reset pin... but not sure if I need this one or not...).

Now I need to learn a bit more about programming.
First I will do a simple single lithiumcell3LED voltage indicator for starters. If this is achieved, I try to figure out the basics of galvanicly isolatedIC to IC communication. The rest should be easy as pie !

[size=small][size=small]*I plan to discharge my batteries no lower than 3v (the Brown-Out-Detection can either be set to 2.7v or 1.8v... for now I am going with 2.7v). It shuts down the chip at the set threshold-voltage, preventing it from giving back faulty results due to brown out. So when one of the cell blocks' IC shuts down, there will be no more communication with the central IC, which can trigger programmed alarming functions (as sending out a message to my phone and cutting offall loads).[/size][/size]