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analogRead() return value according to value set in analogReadResolution() #5776

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Merged
merged 1 commit into from
Oct 24, 2021
Merged

analogRead() return value according to value set in analogReadResolution() #5776

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27 changes: 19 additions & 8 deletions cores/esp32/esp32-hal-adc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,14 +46,23 @@ static uint8_t __analogVRefPin = 0;
#endif

static uint8_t __analogAttenuation = 3;//11db
#if CONFIG_IDF_TARGET_ESP32S2
static uint8_t __analogWidth = 4; // 13 bits
#else
static uint8_t __analogWidth = 3; // 12 bits
#endif
static uint8_t __analogWidth = ADC_WIDTH_MAX - 1; //3 for ESP32/ESP32C3; 4 for ESP32S2
static uint8_t __analogReturnedWidth = SOC_ADC_MAX_BITWIDTH; //12 for ESP32/ESP32C3; 13 for ESP32S2
static uint8_t __analogClockDiv = 1;
static adc_attenuation_t __pin_attenuation[SOC_GPIO_PIN_COUNT];

static inline uint16_t mapResolution(uint16_t value)
{
uint8_t from = __analogWidth + 9;
if (from == __analogReturnedWidth) {
return value;
}
if (from > __analogReturnedWidth) {
return value >> (from - __analogReturnedWidth);
}
return value << (__analogReturnedWidth - from);
}

void __analogSetClockDiv(uint8_t clockDiv){
if(!clockDiv){
clockDiv = 1;
Expand Down Expand Up @@ -150,6 +159,7 @@ void __analogReadResolution(uint8_t bits)
if(!bits || bits > 16){
return;
}
__analogReturnedWidth = bits;
#if CONFIG_IDF_TARGET_ESP32
__analogSetWidth(bits); // hadware from 9 to 12
#endif
Expand All @@ -169,7 +179,7 @@ uint16_t __analogRead(uint8_t pin)
channel -= 10;
r = adc2_get_raw( channel, __analogWidth, &value);
if ( r == ESP_OK ) {
return value;
return mapResolution(value);
} else if ( r == ESP_ERR_INVALID_STATE ) {
log_e("GPIO%u: %s: ADC2 not initialized yet.", pin, esp_err_to_name(r));
} else if ( r == ESP_ERR_TIMEOUT ) {
Expand All @@ -178,9 +188,10 @@ uint16_t __analogRead(uint8_t pin)
log_e("GPIO%u: %s", pin, esp_err_to_name(r));
}
} else {
return adc1_get_raw(channel);
value = adc1_get_raw(channel);
return mapResolution(value);
}
return value;
return mapResolution(value);
}

uint32_t __analogReadMilliVolts(uint8_t pin){
Expand Down