captouch calibration routine: major bugfix

AFE would only get tweaked if it was necessary for the
last pad in the sequence. This can lead to random bad
calibration for any pads except for the last ones.

(also changed behavior to not autocalib in C on boot,
we're doing that OS-side anyways and alternate firmwares
also benefit from developers making an active choice.)

components/flow3r_bsp/flow3r_bsp_ad7147.c

@@ -128,6 +128,15 @@ static bool _channel_afe_tweak(ad7147_chip_t *chip, size_t cix) {
     if (offset > 63) {
         offset = 63;
     }
+
+#if 0
+    // keep around for debugging pls~
+    int32_t old_offset = chip->channels[cix].afe_offset;
+    int32_t chan = cix;
+    ESP_LOGE(TAG, "%s, channel %ld: new afe: %ld, old afe: %ld, reading: %ld", chip->name, chan,
+    offset, old_offset, cur);
+#endif
+
     chip->channels[cix].afe_offset = offset;
     return true;
 }
@@ -140,9 +149,11 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
         // We're doing a calibration cycle on our channels. Instead of writing
         // the data to channel->cdc, write it to channel->amb_meas.
         size_t j = chip->calibration_cycles - 1;
-        for (size_t i = 0; i < len; i++) {
-            chip->channels[_channel_from_readout(chip, i)].amb_meas[j] =
-                data[i];
+        if (j < _AD7147_CALIB_CYCLES) {
+            for (size_t i = 0; i < len; i++) {
+                chip->channels[_channel_from_readout(chip, i)].amb_meas[j] =
+                    data[i];
+            }
         }
     } else {
         // Normal measurement, apply to channel->cdc.
@@ -151,8 +162,7 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
         }
     }
 
-    bool reprogram = _sequence_advance(chip);
-    bool tweak = false;
+    bool reprogram = _sequence_advance(chip) || chip->calibration_external;
 
     // Synchronize on beginning of sequence for calibration logic.
     if (chip->seq_position == 0) {
@@ -160,7 +170,7 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
         if (chip->calibration_pending) {
             if (!chip->calibration_active) {
                 ESP_LOGI(TAG, "%s: calibration starting...", chip->name);
-                chip->calibration_cycles = _AD7147_CALIB_CYCLES;
+                chip->calibration_cycles = _AD7147_CALIB_CYCLES + 2;
                 chip->calibration_active = true;
             }
             chip->calibration_pending = false;
@@ -193,8 +203,7 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
                 // Can we tweak the AFE to get a better measurement?
                 uint16_t rerun = 0;
                 for (size_t i = 0; i < chip->nchannels; i++) {
-                    tweak = _channel_afe_tweak(chip, i);
-                    if (tweak) {
+                    if (_channel_afe_tweak(chip, i)) {
                         rerun |= (1 << i);
                     }
                 }
@@ -205,7 +214,8 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
                              "%s: calibration done, but can do better (%04x). "
                              "Retrying.",
                              chip->name, rerun);
-                    chip->calibration_cycles = _AD7147_CALIB_CYCLES;
+                    chip->calibration_cycles = _AD7147_CALIB_CYCLES + 2;
+                    reprogram = true;
                 } else {
                     chip->calibration_active = false;
                     ESP_LOGI(TAG, "%s: calibration done.", chip->name);
@@ -233,7 +243,7 @@ static void _on_data(void *user, uint16_t *data, size_t len) {
     }
 
     // _sequence_request also writes the AFE registers which just got tweaked
-    if (reprogram || tweak || chip->calibration_external) {
+    if (reprogram) {
         esp_err_t ret;
         if ((ret = _sequence_request(chip, reprogram)) != ESP_OK) {
             COMPLAIN(chip, "%s: requesting next sequence failed: %s",
@@ -255,7 +265,7 @@ esp_err_t flow3r_bsp_ad7147_chip_init(ad7147_chip_t *chip,
     if ((ret = ad7147_hw_init(&chip->dev, address, _on_data, chip)) != ESP_OK) {
         return ret;
     }
-    _calibration_request(chip);
+    // _calibration_request(chip);
     if ((ret = _sequence_request(chip, false)) != ESP_OK) {
         return ret;
     }

components/flow3r_bsp/flow3r_bsp_ad7147_hw.c

@@ -22,6 +22,9 @@
 #define AD7147_REG_DEVICE_ID 0x17
 #define AD7147_REG_STAGE0_CONNECTION 0x80
 
+// uncomment only when u need it else clang-tidy complains
+// static const char *TAG = "flow3r-bsp-ad7147-hw";
+
 // Write single register at `reg`.
 static esp_err_t _i2c_write(const ad7147_hw_t *dev, uint16_t reg,
                             uint16_t data) {
@@ -161,7 +164,14 @@ static esp_err_t _configure_stage(const ad7147_hw_t *dev, uint8_t stage) {
         afe_offset,
         sensitivity,
     };
-    return _i2c_write_multiple(dev, reg, tx, 4);
+    esp_err_t ret = _i2c_write_multiple(dev, reg, tx, 4);
+#if 0
+    uint16_t rx[4];
+    ESP_LOGE(TAG, "write stage config: %u %u %u %u", tx[0], tx[1], tx[2], tx[3]);
+    _i2c_read(dev, reg, rx, 4);
+    ESP_LOGE(TAG, "read stage config:  %u %u %u %u", rx[0], rx[1], rx[2], rx[3]);
+#endif
+    return ret;
 }
 
 // Configure entire device per stage_config and dev_config.