State of Charge Estimation

[digitaldanny]

In this PR:

• Modify ADC interface to allow reading from Open Circuit Voltage (OCV) ADC pin P5.2 (A3) and runtime current draw ADC pin 5.4 (A1).
• Create a State of Charge Cpp API to initialize the ADC pins, update the ADC readings, and calculate the new State of Charge estimation.

[digitaldanny]

Looks like I could change the ADC14 to 8-bit conversions using the following function MAP_ADC14_setResolution(ADC_8BIT);. This will save CPU cycles, but I do not think it is necessary as of now. It would also reduce the need to shift data to the right some amount for compressing the ADC readings. Just leaving this here as a note in case I end up wanting to do this.

[digitaldanny]

Right now I am working on the multi-channel ADC conversions. With my current code, ADC channel 0 works flawlessly; however the following channels are related to the previous ADC conversion. The final ADC3 channel is basically just noise. I am assuming this is an issue of not waiting long enough between conversions.

[digitaldanny]

Fixed the multi-channel ADC issues. With my current implementation, reading from all 4 channels sequentially with the ReadAdcChannel function is not efficient since it will trigger conversions on all 4 channels each time it is called before returning one value. Since my flex sensors API already uses this function and there is still plenty of CPU time for the required tasks, I am just going to leave it as it is.

/*
 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
 * DESCRIPTION: ReadAdcChannel
 * This function triggers the ADC conversion on all 4 channels and returns
 * the requested channel's value.
 *
 * NOTE - This function is not efficient when reading from all 4 channels
 * sequentially since it will trigger a new conversion each time.
 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
 */
uint16_t Adc::MSP432::ReadAdcChannel(uint8_t adc_channel)

[digitaldanny]

I believe I may have blown my in-amp by leaving the external power switch floating. Going to replace this hardware and test it out again later today.

[digitaldanny]

Todo:

• Figure out why the the in-amp on the glove PCB is not producing an amplified voltage output. Should be seeing values on a scale of about 0.6 - 1V with 100x amplification, but I am seeing values around 0.02.
  • I tested another in-amp that I know is functioning properly. Using the shunt resistor drop and a voltmeter, I see values around 0.02V.
  • The functional in-amp test worked with my DAD board's power supply but not with the MSP432 3.3V/GND lines. I am wondering if the power supply has something to do with the issues I am seeing.
  • Maybe this is an input current issue? I could try using larger voltage divider resistors, but I doubt this is the solution.
• Implement the State of Charge code using the updated ADC interface.

[digitaldanny]

Implemented the static SOC estimation. May return to dynamic SOC estimation later if time permits.