1 files changed, 42 insertions, 52 deletions

diff --git a/ports/esp32/adc.c b/ports/esp32/adc.c
index 83af6dce0b..d0e5e81330 100644
--- a/ports/esp32/adc.c
+++ b/ports/esp32/adc.c
@@ -26,83 +26,73 @@
  */
 
 #include "py/mphal.h"
+#include "py/mperrno.h"
 #include "adc.h"
-#include "driver/adc.h"
+#include "esp_adc/adc_oneshot.h"
 #include "esp_adc/adc_cali_scheme.h"
 
-#define DEFAULT_VREF 1100
+static esp_err_t ensure_adc_calibration(machine_adc_block_obj_t *self, adc_atten_t atten);
 
-void madcblock_bits_helper(machine_adc_block_obj_t *self, mp_int_t bits) {
-    if (bits < SOC_ADC_RTC_MIN_BITWIDTH && bits > SOC_ADC_RTC_MAX_BITWIDTH) {
-        // Invalid value for the current chip, raise exception in the switch below.
-        bits = -1;
+void adc_is_init_guard(machine_adc_block_obj_t *self) {
+    if (!self->handle) {
+        mp_raise_OSError(MP_EPERM);
     }
-    switch (bits) {
-        case 9:
-            self->width = ADC_BITWIDTH_9;
-            break;
-        case 10:
-            self->width = ADC_BITWIDTH_10;
-            break;
-        case 11:
-            self->width = ADC_BITWIDTH_11;
-            break;
-        case 12:
-            self->width = ADC_BITWIDTH_12;
-            break;
-        case 13:
-            self->width = ADC_BITWIDTH_13;
-            break;
-        default:
-            mp_raise_ValueError(MP_ERROR_TEXT("invalid bits"));
-    }
-    self->bits = bits;
+}
 
-    if (self->unit_id == ADC_UNIT_1) {
-        adc1_config_width(self->width);
-    }
+esp_err_t apply_self_adc_channel_atten(const machine_adc_obj_t *self, uint8_t atten) {
+    adc_is_init_guard(self->block);
+
+    adc_oneshot_chan_cfg_t config = {
+        .atten = atten,
+        .bitwidth = self->block->bitwidth,
+    };
+    esp_err_t ret = adc_oneshot_config_channel(self->block->handle, self->channel_id, &config);
+    return ret;
 }
 
 mp_int_t madcblock_read_helper(machine_adc_block_obj_t *self, adc_channel_t channel_id) {
-    int raw = 0;
-    if (self->unit_id == ADC_UNIT_1) {
-        raw = adc1_get_raw(channel_id);
-    } else {
-        #if (SOC_ADC_PERIPH_NUM >= 2)
-        check_esp_err(adc2_get_raw(channel_id, self->width, &raw));
-        #endif
-    }
-    return raw;
+    adc_is_init_guard(self);
+
+    int reading = 0;
+    adc_oneshot_read(self->handle, channel_id, &reading);
+    return reading;
+}
+
+/*
+During testing, it turned out that the function `adc_cali_raw_to_voltage` does not account for the lower resolution,
+instead it expects the full resolution value as an argument, hence the scaling applied here
+*/
+mp_int_t madcblock_read_uv_helper(machine_adc_block_obj_t *self, adc_channel_t channel_id, adc_atten_t atten) {
+    int raw = madcblock_read_helper(self, channel_id);
+    int uv = 0;
+
+    check_esp_err(ensure_adc_calibration(self, atten));
+    check_esp_err(adc_cali_raw_to_voltage(self->calib[atten], (raw << (ADC_WIDTH_MAX - self->bitwidth)), &uv));
+    return (mp_int_t)uv * 1000;
 }
 
 static esp_err_t ensure_adc_calibration(machine_adc_block_obj_t *self, adc_atten_t atten) {
-    if (self->handle[atten] != NULL) {
+    if (self->calib[atten] != NULL) {
         return ESP_OK;
     }
 
+    esp_err_t ret = ESP_OK;
+
     #if ADC_CALI_SCHEME_CURVE_FITTING_SUPPORTED
     adc_cali_curve_fitting_config_t cali_config = {
         .unit_id = self->unit_id,
         .atten = atten,
-        .bitwidth = self->width,
+        .bitwidth = self->bitwidth,
     };
-    return adc_cali_create_scheme_curve_fitting(&cali_config, &self->handle[atten]);
+    ret = adc_cali_create_scheme_curve_fitting(&cali_config, &self->calib[atten]);
     #else
     adc_cali_line_fitting_config_t cali_config = {
         .unit_id = self->unit_id,
         .atten = atten,
-        .bitwidth = self->width,
+        .bitwidth = self->bitwidth,
     };
-    return adc_cali_create_scheme_line_fitting(&cali_config, &self->handle[atten]);
+    ret = adc_cali_create_scheme_line_fitting(&cali_config, &self->calib[atten]);
     #endif
-}
 
-mp_int_t madcblock_read_uv_helper(machine_adc_block_obj_t *self, adc_channel_t channel_id, adc_atten_t atten) {
-    int raw = madcblock_read_helper(self, channel_id);
-    int uv;
-
-    check_esp_err(ensure_adc_calibration(self, atten));
-    check_esp_err(adc_cali_raw_to_voltage(self->handle[atten], raw, &uv));
-
-    return (mp_int_t)uv * 1000;
+    return ret;
 }