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LTC6811 Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltc6811-1-6811-2.pdf
Issue 1: OS Error Assertion after Scheduler Unlock
We realized the BPS was reaching EnterFaultState() pretty early on; specifically, whenever RTOS_BPS_DelayUs was called (after looking at the backtrace on GDB). The code below shows where we were entering FaultState.
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if(err != OS_ERR_SCHED_LOCKED) assertOSError(err); |
Issue 2: Different Cell Configuration
Each minion module has the capacity to read from 12 voltage sensors, for a total of 36 voltage readings, however we do not use all 36 readings.
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Note that this is a bit of a hacky fix. Ideally the code would be slightly restructured to allow for variable amounts of voltage sensors per minion board, and the macro values in config.h would be the only things needing to be edited, but this works for the time being.
Issue 3: Invalid Readings
Here is a printout of the Voltages array (all thirty-two sensor readings).
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The problem sensors have been highlighted in red. Sensor 11 of Module 1, Sensor 10 of Module 2, and Sensors 9/10/11 of Module 3. What really bugs me about this issue is the fact that it's not simply just the last voltage sensor on each module that's faulting, but also the last three sensors on module 3.
Possible Issue Idea 1:
One possible issue is that the LTC isn't getting enough power to properly operate on the last few cells. Here's the diagram of our input to the LTC:
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In my opinion there wouldn't be much of a difference between these two options, but I'm on the side of just following what the datasheet says to do since there may be some weird current flow stuff if we just connect the nodes externally. Plus it wouldn't be too difficult to solder a trace on if this is actually the issue.
Issue 3.1: Last Value in Minion is Invalid
PROBLEM CHILDREN 3: 3/21/24
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