If you have used the original 47k thermistors, then you can leave those as they are, but you would need to change a resistor on each of the modules to match.
Yes, def. and issue between those modules - good investigation work.
Its probably worth re-making the JST cable between the two modules and double check the soldering to the ATTINY.
The cable I have already checked and tested with another one - the same issue, so probably the soldering to the ATTINY. I will check it after work.
Many thanks =)
If you move that module/swap it with another one, you can see if the problem moves with it.
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Yes I will try this also. Or replacing it with a spare board and check if the problem is gone.
Calibration/best practices question for v4.21 modules. How much are yours off from real voltage and do you calibrate them?
For example in my case
voltage differences are from 3.296 to 3.327V (31mV) though with voltmeter it is only 3.321 Ā± 2mV.
Also these are 4 banks so I am tempted to calibrate all modules needed so that all 4 banks would have closer voltages (cables are equal length).
Or is it just overkill which might cause more headacke in the future?
@stuart Iām trying (as many others I guess) to get hold of all the bits needed for the ESP32 control circuit.
Started with the easy (for me) one which is the TJA1057GT/3 can chip.
I have a dozen or so MCP2562 DIP chips from my NMEA2000 project. I checked the specs of the two and it is identical (donāt think Iāve missed something!)
So am I right in saying that I could simply edit the board add the support for the DIP version (even pinout is identical) and use it?
Sadly Iāve not had any luck finding something for the two TCA chips. I wonder if for testing purposes the board would work without them. Easy to sort the two capacitors, the diode and a triple led that are also missing.
cheers
V.
Both TCA chips are essential. Without them controller on ESP32 would not start.
It would be good to think what can replace a both TCA chips. It may be a PCF8574 widely used as arduino port extender.
They should be fairly accurate as built, however yes you do need to calibrate the modules.
You should be able to get around 4mV resolution.
Stop any charge or discharge of the battery, then take multi meter reading of each cell, enter that in the configuration web page and it should improve things a lot.
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Iāve also not had much luck finding the parts!
well nothing serious to do this morning, so thought Iāll have a go at doing an OAP version of the 4.3 CC board 
Idea is to find place to squeeze 2XDIP16 for the TCAs and 1XDIP8 for the TJA.
Done two already, one to go, obvs you either solder the SMD or get a suitable (?) DIP in the other spot. Tracks go to both so board should work with either on.
Pretty certain MCP2562 will be fine for CAN have used quite a few in similar projects with arduinos.
Also seems that PCF8574 will be good for the TCA9534A (from a non exhaustive check in the specs: voltage range is the same, pin compatible)
cheers
V.
Interesting work there @vas !!
Just watch the CANBUS and TCA/PCF chips - they need to support 3.3V for the ESP32 but switch 5V for the relays and input/outputs. Not all models support those configurations.
ā¦ if only I knew this KiCAD program a bit. Installed it in the morning, spent 4h doing the three DIP addons and Iām struggling for over an hour to find how to get proper files for JLCPCB printingā¦
Gerber looks fine in JLCPCB tool, BOM looks crap, CPL looks fine 
JLC wont accept it
Does someone have a list of suitable alternatives for the
22UF 6.3V caps and
SRD-05VDC-SL-C
For the caps im looking at either
Mouser: 80-T494A226K006
or
Mouser: 581-TAJA226K006RNJV
Iām about to order 5 boards and Iām going to order C118989 (from the LCSC catalog) or:
https://lcsc.com/product-detail/Tantalum-Capacitors_KEMET-T491A226K006AT_C118989.html
itās available on JCLPCB.
the relay seems to be a bog standard relay (trigger v must be right though)
V.
Ye thatās the first one I listed from mouser, ordered some along with the ATTINY841ās.
The relay Iām just scared about the size and if I can find an exact substitute. After that then all thatās left is
|5x ||TCA6408APWR|
|5x ||TCA9534A|
|5x ||TJA1057GT/3|
er, are you sure?
as of this evening SN65HVD75DR is out of stock as well!
unless youāve actually ordered the boards alreadyā¦
Iāve ordered already and those were out of stock, I got those via mouser too