Setup
Connected to a 12S 1P Li-ion battery stack (some of the many old laptop batteries that were hanging around my basement).
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I dropped the board. It landed on the screw hole. Maybe we should consider moving the screws away from the edge of the board a little more? But the main point here is that I should have been more careful with the board. It landed on a thin rubber mat on the floor in my work area.
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Power Validation
All power nets are not connected. Good.
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The board seems to be resetting at a rate independent of the rate at which I toggle the CS pin. By resetting, I mean the 5V LED toggling off (for a short time, about 100ms before turning back on). So the device seems to be going into a sleep state or something before waking up again via the SPI command.
Battery Stack Monitor
Gerald Aryeetey (Deactivated) and Micah Black tried to get the LTC6811 chip to talk using code from the old car, modified to work with just 1 AFE.
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Any thoughts Liam Hawkins ?
Debugging Jun 6 2020
Going off the last comment of the SPI lines being shorted, I double checked them and they seemed to be fine. No shorts that I could see. I measured the other SPI bus on the carrier (for the Current Sense) and it was not shorted - which seemed like the expected behaviour.
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Overall, voltage reading is a success!
Temperature Readings
-I need to attach some thermistors first…
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Thermistor Cell Input number | Bottom Resistor Value | Expected Voltage (10k upper resistor, 3V0 ref) | Temperature Result Expected |
|---|---|---|---|
0 | 10k | 1.5 | 25 |
1 | 3.3k | 0.74436 | 52 |
2 | 10k | 1.5 | 25 |
3 | 4.7k | 0.959186 | 43 |
4 | 10k | 1.5 | 25 |
5 | 5.1k | 1.013245 | 41 |
6 | 10k | 1.5 | 25 |
7 | 6.8k | 1.214285 | 34 |
8 | 10k | 1.5 | 25 |
9 | 10k pot | 0-1.5 | 25+ |
10 | 10k | 1.5 | 25 |
11 | 3.3k | 0.74436 | 52 |
12 | 4.7k | 0.959186 | 43 |
13 | 5.1k | 1.013245 | 41 |
14 | 6.8k | 1.214285 | 34 |
15 | 10k | 1.5 | 25 |
16 | 10k | 1.5 | 25 |
17 | 1.5@25C | 25 |
Updates Jun 9, 2020
There were a few bugs to work out in the code to print the values, but they didn’t match what was expected. I probed the COMM lines between the 2 chips, and there was nothing - just held to 5V for 2s (beofore the chip goes to sleep) with the pullup resistor. (pins 17,18,19)
I also probed the output of the chip - pulled to GND for the whole time. (pin 43)
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