BMS AFE 2.0 Validation

This page will document the validation conducted for the AFE interfacing with BMS Carrier.

IsoSPI validation

This document was created a few hours after initial debug of the isoSPI system from carrier to AFE, and will summarize the debug in that time frame.

Basically, there was a mistake in the populating of both the AFEs and carrier in which the AFEs did not have the isoSPI communication resistors properly depopulated for the LTC6811. This was fixed on 2/3 of the AFEs (not yet the one with the broken pin on the LTC6811) and should be modified in the schematics for future reference. The next problem was on carrier side in which there was a pull down resistor for a voltage divider across the pins of the LTC6820 that was not supposed to be depopulated but a changing of the designators from and old revision had it marked as depop on the schematics. Another issue

Firmware output from the project smoke_ltc6811 with number of cells set to 24 and number of devices set to 2:

Basically, shit works!

Open

From one AFE and 12 cells, here are the recorded readings (converted to volts) vs a multimeter reading: