Software

(aside: I think something went south on the first attempt of this post so this may be a duplicate)

I'm writing unit/feature tests of the serial protocol API and I'm working on the analog read command (Ra<pin>). The pin I use (VOLTAGE, pin 4) comes from the lowBattery function in reaction.h and is defined in opencat.h.

The test is performed on a fully changed battery. I'm having difficulty understanding the response:

=
383
R

I expected to get a value between 0 - 4096 but at the high end of the range. The lowBattery code reads the value into a float

bool lowBattery() {
    //...
    float voltage = analogRead(VOLTAGE);

and compares the value with a precalculated low_voltage value:

//...
float vFactor = 4096 / 3.3 / 3;
float low_voltage = LOW_VOLTAGE * vFactor;
//...
if (voltage == 0 || voltage < low_voltage ...)

The value of vFactor should be 413.73..., and thus the value of low_voltage is 2813.41...

This doesn't look right. So, I'm missing something here. Is the command response (383) valid? I expect it to be an integer. I don't understand the calculation in lowBattery.

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