Power improvements (#114)

Boards/LilygoTdeck/CMakeLists.txt

@@ -1,5 +1,5 @@
 idf_component_register(
     SRC_DIRS "Source" "Source/hal"
     INCLUDE_DIRS "Source"
-    REQUIRES Tactility esp_lvgl_port esp_lcd esp_lcd_touch_gt911 driver vfs fatfs
+    REQUIRES Tactility esp_lvgl_port esp_lcd esp_lcd_touch_gt911 driver vfs fatfs esp_adc
 )

Boards/LilygoTdeck/Source/InitHardware.cpp

@@ -2,7 +2,6 @@
 #include "hal/TdeckDisplayConstants.h"
 #include <driver/spi_common.h>
 #include <soc/gpio_num.h>
-#include <driver/ledc.h>
 
 #define TAG "tdeck"
 
@@ -19,7 +18,6 @@
 #define TDECK_LCD_BACKLIGHT_LEDC_DUTY_RES LEDC_TIMER_8_BIT
 #define TDECK_LCD_BACKLIGHT_LEDC_FREQUENCY (4000)
 
-
 static bool init_spi() {
     spi_bus_config_t bus_config = {
         .mosi_io_num = TDECK_SPI_PIN_MOSI,

Boards/LilygoTdeck/Source/LilygoTdeck.cpp

@@ -1,6 +1,7 @@
 #include "hal/Configuration.h"
 #include "hal/TdeckDisplay.h"
 #include "hal/TdeckKeyboard.h"
+#include "hal/TdeckPower.h"
 #include "hal/sdcard/Sdcard.h"
 
 bool tdeck_init_power();
@@ -16,7 +17,7 @@ extern const tt::hal::Configuration lilygo_tdeck = {
     .createDisplay = createDisplay,
     .createKeyboard = createKeyboard,
     .sdcard = &tdeck_sdcard,
-    .power = nullptr,
+    .power = tdeck_get_power,
     .i2c = {
         tt::hal::i2c::Configuration {
             .name = "Internal",

Boards/LilygoTdeck/Source/hal/TdeckPower.cpp

@@ -0,0 +1,135 @@
+#include "TdeckPower.h"
+
+#include "Log.h"
+#include "CoreDefines.h"
+
+#define TAG "power"
+
+/**
+ * The ratio of the voltage divider is supposedly 2.0, but when we set that, the ADC reports a bit over 4.45V
+ * when charging the device.
+ * There was also supposedly a +0.11 sag compensation related to "display under-voltage" according to Meshtastic firmware.
+ * Either Meshtastic implemented it incorrectly OR there is simply a 5-10% deviation in accuracy.
+ * The latter is feasible as the selected resistors for the voltage divider might not have been matched appropriately.
+ */
+#define ADC_MULTIPLIER 1.89f
+
+#define ADC_REF_VOLTAGE 3.3f
+#define BATTERY_VOLTAGE_MIN 3.2f
+#define BATTERY_VOLTAGE_MAX 4.2f
+
+static adc_oneshot_unit_init_cfg_t adcConfig = {
+    .unit_id = ADC_UNIT_1,
+    .clk_src = ADC_RTC_CLK_SRC_DEFAULT,
+    .ulp_mode = ADC_ULP_MODE_DISABLE,
+};
+
+static adc_oneshot_chan_cfg_t adcChannelConfig = {
+    .atten = ADC_ATTEN_DB_12,
+    .bitwidth = ADC_BITWIDTH_DEFAULT,
+};
+
+static uint8_t estimateChargeLevelFromVoltage(uint32_t milliVolt) {
+    float volts = TT_MIN((float)milliVolt / 1000.f, BATTERY_VOLTAGE_MAX);
+    float voltage_percentage = (volts - BATTERY_VOLTAGE_MIN) / (BATTERY_VOLTAGE_MAX - BATTERY_VOLTAGE_MIN);
+    float voltage_factor = TT_MIN(1.0f, voltage_percentage);
+    auto charge_level = (uint8_t) (voltage_factor * 100.f);
+    TT_LOG_V(TAG, "mV = %lu, scaled = %.2f, factor = %.2f, result = %d", milliVolt, volts, voltage_factor, charge_level);
+    return charge_level;
+}
+
+TdeckPower::TdeckPower() {
+    if (adc_oneshot_new_unit(&adcConfig, &adcHandle) != ESP_OK) {
+        TT_LOG_E(TAG, "ADC config failed");
+        return;
+    }
+
+    if (adc_oneshot_config_channel(adcHandle, ADC_CHANNEL_3, &adcChannelConfig) != ESP_OK) {
+        TT_LOG_E(TAG, "ADC channel config failed");
+
+        adc_oneshot_del_unit(adcHandle);
+        return;
+    }
+}
+
+TdeckPower::~TdeckPower() {
+    if (adcHandle) {
+        adc_oneshot_del_unit(adcHandle);
+    }
+}
+
+bool TdeckPower::supportsMetric(MetricType type) const {
+    switch (type) {
+        case BATTERY_VOLTAGE:
+        case CHARGE_LEVEL:
+            return true;
+        case IS_CHARGING:
+        case CURRENT:
+            return false;
+    }
+
+    return false; // Safety guard for when new enum values are introduced
+}
+
+bool TdeckPower::getMetric(Power::MetricType type, Power::MetricData& data) {
+    switch (type) {
+        case BATTERY_VOLTAGE:
+            return readBatteryVoltageSampled(data.valueAsUint32);
+        case CHARGE_LEVEL:
+            if (readBatteryVoltageSampled(data.valueAsUint32)) {
+                data.valueAsUint32 = estimateChargeLevelFromVoltage(data.valueAsUint32);
+                return true;
+            } else {
+                return false;
+            }
+        case IS_CHARGING:
+        case CURRENT:
+            return false;
+    }
+
+    return false; // Safety guard for when new enum values are introduced
+}
+
+bool TdeckPower::readBatteryVoltageOnce(uint32_t& output) {
+    int raw;
+    if (adc_oneshot_read(adcHandle, ADC_CHANNEL_3, &raw) == ESP_OK) {
+        output = ADC_MULTIPLIER * ((1000.f * ADC_REF_VOLTAGE) / 4096.f) * (float)raw;
+        TT_LOG_V(TAG, "Raw = %d, voltage = %lu", raw, output);
+        return true;
+    } else {
+        TT_LOG_E(TAG, "Read failed");
+        return false;
+    }
+}
+
+#define MAX_VOLTAGE_SAMPLES 15
+
+bool TdeckPower::readBatteryVoltageSampled(uint32_t& output) {
+    size_t samples_read = 0;
+    uint32_t sample_accumulator = 0;
+    uint32_t sample_read_buffer;
+
+    for (size_t i = 0; i < MAX_VOLTAGE_SAMPLES; ++i) {
+        if (readBatteryVoltageOnce(sample_read_buffer)) {
+            sample_accumulator += sample_read_buffer;
+            samples_read++;
+        }
+    }
+
+    if (samples_read > 0) {
+        output = sample_accumulator / samples_read;
+        return true;
+    } else {
+        return false;
+    }
+}
+
+static std::shared_ptr<Power> power;
+
+std::shared_ptr<Power> tdeck_get_power() {
+    if (power == nullptr) {
+        power = std::make_shared<TdeckPower>();
+    }
+    return power;
+}
+

Boards/LilygoTdeck/Source/hal/TdeckPower.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "hal/Power.h"
+#include <esp_adc/adc_oneshot.h>
+#include <memory>
+
+using namespace tt::hal;
+
+class TdeckPower : public Power {
+
+    adc_oneshot_unit_handle_t adcHandle = nullptr;
+
+public:
+
+    TdeckPower();
+    ~TdeckPower();
+
+    bool supportsMetric(MetricType type) const override;
+    bool getMetric(Power::MetricType type, Power::MetricData& data) override;
+
+private:
+
+    bool readBatteryVoltageSampled(uint32_t& output);
+    bool readBatteryVoltageOnce(uint32_t& output);
+};
+
+std::shared_ptr<Power> tdeck_get_power();

Boards/M5stackCore2/Source/M5stackCore2.cpp

@@ -1,12 +1,13 @@
 #include "M5stackCore2.h"
 #include "M5stackShared.h"
+#include "hal/M5stackPower.h"
 
 extern const tt::hal::Configuration m5stack_core2 = {
-    .initBoot = &m5stack_bootstrap,
-    .initLvgl = &m5stack_lvgl_init,
+    .initBoot = m5stack_bootstrap,
+    .initLvgl = m5stack_lvgl_init,
     .createDisplay = createDisplay,
     .sdcard = &m5stack_sdcard,
-    .power = &m5stack_power,
+    .power = m5stack_get_power,
     .i2c = {
         tt::hal::i2c::Configuration {
             .name = "Internal",

Boards/M5stackCoreS3/Source/M5stackCoreS3.cpp

@@ -1,12 +1,13 @@
 #include "M5stackCoreS3.h"
 #include "M5stackShared.h"
+#include "hal/M5stackPower.h"
 
 const tt::hal::Configuration m5stack_cores3 = {
-    .initBoot = &m5stack_bootstrap,
-    .initLvgl = &m5stack_lvgl_init,
+    .initBoot = m5stack_bootstrap,
+    .initLvgl = m5stack_lvgl_init,
     .createDisplay = createDisplay,
     .sdcard = &m5stack_sdcard,
-    .power = &m5stack_power,
+    .power = m5stack_get_power,
     .i2c = {
         tt::hal::i2c::Configuration {
             .name = "Internal",

Boards/M5stackShared/Source/M5stackShared.h

@@ -8,5 +8,4 @@
 extern bool m5stack_bootstrap();
 extern bool m5stack_lvgl_init();
 
-extern const tt::hal::Power m5stack_power;
 extern const tt::hal::sdcard::SdCard m5stack_sdcard;

Boards/M5stackShared/Source/Power.cpp

@@ -1,38 +0,0 @@
-#include "hal/Power.h"
-#include "M5Unified.hpp"
-
-/**
- * M5.Power by default doesn't have a check to see if charging is enabled.
- * However, it's always enabled by default after boot, so we cover that here:
- */
-static bool charging_enabled = true;
-
-static bool is_charging() {
-    return M5.Power.isCharging() == m5::Power_Class::is_charging;
-}
-
-static bool is_charging_enabled() {
-    return charging_enabled;
-}
-
-static void set_charging_enabled(bool enabled) {
-    charging_enabled = enabled; // Local shadow copy because M5 API doesn't provide a function for it
-    M5.Power.setBatteryCharge(enabled);
-}
-
-static uint8_t get_charge_level() {
-    uint16_t scaled = (uint16_t)M5.Power.getBatteryLevel() * 255 / 100;
-    return (uint8_t)scaled;
-}
-
-static int32_t get_current() {
-    return M5.Power.getBatteryCurrent();
-}
-
-extern const tt::hal::Power m5stack_power = {
-    .isCharging = &is_charging,
-    .isChargingEnabled = &is_charging_enabled,
-    .setChargingEnabled = &set_charging_enabled,
-    .getChargeLevel = &get_charge_level,
-    .getCurrent = &get_current
-};

Boards/M5stackShared/Source/hal/M5stackPower.cpp

@@ -0,0 +1,50 @@
+#include "M5stackPower.h"
+
+#include "M5Unified.h"
+
+#define TAG "m5stack_power"
+
+bool M5stackPower::supportsMetric(MetricType type) const {
+    switch (type) {
+        case IS_CHARGING:
+        case CURRENT:
+        case BATTERY_VOLTAGE:
+        case CHARGE_LEVEL:
+            return true;
+    }
+
+    return false; // Safety guard for when new enum values are introduced
+}
+
+bool M5stackPower::getMetric(Power::MetricType type, Power::MetricData& data) {
+    switch (type) {
+        case IS_CHARGING:
+            data.valueAsBool = M5.Power.isCharging();
+            return true;
+        case CURRENT:
+            data.valueAsInt32 = M5.Power.getBatteryCurrent();
+            return true;
+        case BATTERY_VOLTAGE:
+            data.valueAsUint32 = M5.Power.getBatteryVoltage();
+            return true;
+        case CHARGE_LEVEL:
+            data.valueAsUint8 = M5.Power.getBatteryLevel();
+            return true;
+    }
+
+    return false; // Safety guard for when new enum values are introduced
+}
+
+void M5stackPower::setAllowedToCharge(bool canCharge) {
+    M5.Power.setBatteryCharge(canCharge);
+}
+
+static std::shared_ptr<Power> power;
+
+std::shared_ptr<Power> m5stack_get_power() {
+    if (power == nullptr) {
+        power = std::make_shared<M5stackPower>();
+    }
+    return power;
+}
+

Boards/M5stackShared/Source/hal/M5stackPower.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "hal/Power.h"
+#include <memory>
+
+using namespace tt::hal;
+
+class M5stackPower : public Power {
+
+public:
+
+    M5stackPower() {}
+    ~M5stackPower() {}
+
+    bool supportsMetric(MetricType type) const override;
+    bool getMetric(Power::MetricType type, Power::MetricData& data) override;
+
+    bool supportsChargeControl() const { return true; }
+    bool isAllowedToCharge() const { return true; } /** We can call setChargingAllowed() but the actual value is unknown as it resets when re-plugging USB */
+    void setAllowedToCharge(bool canCharge);
+};
+
+std::shared_ptr<Power> m5stack_get_power();