diff options
Diffstat (limited to 'src/glutt-o-logique/analog_input.c')
| -rw-r--r-- | src/glutt-o-logique/analog_input.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/glutt-o-logique/analog_input.c b/src/glutt-o-logique/analog_input.c index 8b65cf8..d970238 100644 --- a/src/glutt-o-logique/analog_input.c +++ b/src/glutt-o-logique/analog_input.c @@ -39,7 +39,7 @@ void analog_init(void) GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; - GPIO_Init(GPIOC, &GPIO_InitStructure); + GPIO_Init(GPIOA, &GPIO_InitStructure); // Init ADC1 for supply measurement ADC_CommonInitTypeDef ADC_CommonInitStruct; @@ -78,12 +78,15 @@ float analog_measure_12v(void) // TODO add timeout while (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET); - const float raw_value = ADC_GetConversionValue(ADC1); + const uint16_t raw_value = ADC_GetConversionValue(ADC1); - // Voltage divider 22k / (82k + 22k) must be inverted here - // Also, we round to steps of 0.5 - float voltage = raw_value * (2.0f * 104.0f / 22.0f); - voltage = roundf(voltage); - voltage = voltage / 2.0f; - return voltage; + const float adc_max_value = (1 << 12); + const float v_ref = 2.965f; + + // Convert ADC measurement to voltage + float voltage = ((float)raw_value*v_ref/adc_max_value); + + // Compensate resistor divider on board (see schematic) + return voltage * 202.0f / 22.0f; } + |