Battery ADC gizmo setup

[sliwowitz]

I'm trying to read battery voltage from a voltage divider connected to pin 34 on an ESP32 (with a 30-pin breakout board). I'm also using madflight_board.h which in my case includes madflight_board_ESP32.h whcih seems to have the same pinout as the 30-pin breakout (for those pins that are present)

I've put this in my madflight_config.h:

bat_gizmo      ADC  // options: NONE, ADC, INA226, INA228
//bat_i2c_adr    0
//bat_i2c_bus   -1
//pin_bat_i     -1
pin_bat_v       34
bat_cal_v       12.3 
//bat_cal_i      1

but I'm just getting zeros. Actually I'm not even sure the gizmo is initialized because I'm still getting zeroes even if I hardcode something like state->v = 1.0 in BatGizmoADC::update()

The wiring should be fine - I have a small sketch to test all the sensors, and I can get the correct battery reading with code like:

setup(){
    analogSetPinAttenuation(PIN_BATTERY_VOLTAGE, ADC_11db);
    analogSetWidth(12); 
}
loop(){
    int raw_value = analogRead(PIN_BATTERY_VOLTAGE);
    float v_adc = (raw_value / 4095.0) * 3.3f;
    float voltage = v_adc * CALIBRATION_FACTOR;
}

The digital sensors like IMU and BAR are working fine with minimal changes done to madflight_config.h (showing just the uncommented lines—most defaults coming from the board config are OK for my build)

imu_gizmo      MPU6500
imu_bus_type   SPI 
imu_align      CW0
imu_spi_bus    0 //spi

bar_gizmo      BMP390 
bar_i2c_adr    119 // = 0x77
bar_i2c_bus    0

running the ESP32, I see:

...
BAT: ADC - cal_v:12.300000 cal_i:1.000000 i2c_bus:0 i2c_adr:0
...
> pacc  
ax:+0.11        ay:-0.01        az:+1.03   
> pbar  
bar.alt:235.51  press:98528.1   temp:25.14      
> pbat  
bat.v:0.00      bat.i:+0.00     bat.mah:+0.00   bat.wh:+0.00  

[qqqlab]

Strange... Did you try v2.0.2-DEV? I did a quick test with "helloworld.ino" on a ESP32 dev board and it works fine for me:

bat_gizmo      ADC  
pin_bat_v     34
bat_cal_v      1

//turning a potmeter connected to pin 34 from +3.3V to GND gives:
> pbat 
bat.v:65520.00	bat.i:+0.00	bat.mah:+0.00	bat.wh:+0.00	
bat.v:57776.00	bat.i:+0.00	bat.mah:+0.00	bat.wh:+0.00	
bat.v:25856.00	bat.i:+0.00	bat.mah:+0.00	bat.wh:+0.00	
bat.v:0.00	bat.i:+0.00	bat.mah:+0.00	bat.wh:+0.00	

[sliwowitz]

I'm actually using platformio.ini with lib_deps = https://github.com/qqqlab/madflight.git, so it's the main branch.

BTW, I just sat down to try it now, and was very confused that a new helloworld project I made wouldn't find madflight headers while the old one worked fine, then I saw you made a "new directory tree" commit just an hour ago 😅 Gonna update my projects, and try again.

[sliwowitz]

Ah! My bad, I wasn't calling bat.update() 🤦