Add support for tdisplays3 (and others) : Read battery level and charging status

main/Kconfig.projbuild

@@ -131,7 +131,14 @@ menu "Blockstream Jade"
         default n
         help
             Jade v1 (and some other devices) come with the AXP192 to manage power to ESP, display, camera
-
+
+    config HAS_BATTERY
+        bool "Use analog input as battery level indicator and USB connection"
+        depends on BOARD_TYPE_TTGO_TDISPLAYS3
+        default n
+        help
+            Some devices can measure voltage and detect charging status through an analog input.
+
     menu "SDA/SCL Pin Mapping"
         visible if BOARD_TYPE_CUSTOM
 

main/power.c

@@ -24,6 +24,9 @@
 #include "power/twatchs3.inc"
 #elif defined(CONFIG_HAS_IP5306)
 #include "power/ip5306.inc"
+// ttgo-tdisplays3 can read battery level and charging status if a battery is connected
+#elif defined(CONFIG_BOARD_TYPE_TTGO_TDISPLAYS3) && defined(CONFIG_HAS_BATTERY)
+#include "power/tdisplays3.inc"
 #else
 // Stubs for other hw boards (ie. no power management)
 #include "power/minimal.inc"

main/power/tdisplays3.inc

@@ -0,0 +1,95 @@
+// tdisplays3 and devices with no power-management but it can measure voltage level of the battery and
+// detect charging status when a battery is connected through an analog input
+//
+#include <driver/gpio.h>
+#include <esp_adc/adc_cali.h>
+#include <esp_adc/adc_oneshot.h>
+
+#define BATTERY_ADC_CHANNEL ADC_CHANNEL_3
+
+static adc_oneshot_unit_handle_t adc1_handle = NULL;
+static adc_cali_handle_t adc1_cali_handle = NULL;
+
+esp_err_t power_init(void)
+{
+    // Initialise the ADC to measure battery level
+    adc_oneshot_unit_init_cfg_t init_config1 = {
+        .unit_id = ADC_UNIT_1,
+    };
+    ESP_ERROR_CHECK(adc_oneshot_new_unit(&init_config1, &adc1_handle));
+    JADE_ASSERT(adc1_handle);
+    // ADC Config
+    adc_oneshot_chan_cfg_t config = {
+        .atten = ADC_ATTEN_DB_12,
+        .bitwidth = ADC_BITWIDTH_DEFAULT,
+    };
+    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc1_handle, BATTERY_ADC_CHANNEL, &config));
+    // Curve fitting calibration
+    adc_cali_curve_fitting_config_t cali_config = {
+        .unit_id = ADC_UNIT_1,
+        .atten = ADC_ATTEN_DB_12,
+        .bitwidth = ADC_BITWIDTH_DEFAULT,
+    };
+    ESP_ERROR_CHECK(adc_cali_create_scheme_curve_fitting(&cali_config, &adc1_cali_handle));
+    return ESP_OK;
+}
+
+esp_err_t power_shutdown(void) { return ESP_OK; }
+esp_err_t power_screen_on(void) { return ESP_OK; }
+esp_err_t power_backlight_on(const uint8_t brightness) { return ESP_OK; }
+esp_err_t power_backlight_off(void) { return ESP_OK; }
+esp_err_t power_camera_on(void) { return ESP_OK; }
+esp_err_t power_camera_off(void) { return ESP_OK; }
+
+uint16_t power_get_vbat(void)
+{
+    JADE_ASSERT(adc1_handle);
+    int cal_vbat = 0;
+    int raw_vbat = 0;
+    ESP_ERROR_CHECK(adc_oneshot_read(adc1_handle, BATTERY_ADC_CHANNEL, &raw_vbat));
+    ESP_ERROR_CHECK(adc_cali_raw_to_voltage(adc1_cali_handle, raw_vbat, &cal_vbat));
+    return (uint16_t)(cal_vbat * 2);
+}
+uint8_t power_get_battery_status(void)
+{
+    const uint16_t vbat = power_get_vbat();
+
+    if (vbat > 4000) {
+        return 5;
+    } else if (vbat > 3800) {
+        return 4;
+    } else if (vbat > 3600) {
+        return 3;
+    } else if (vbat > 3400) {
+        return 2;
+    } else if (vbat > 3200) {
+        return 1;
+    }
+    return 0;
+}
+
+bool power_get_battery_charging(void)
+{
+    uint16_t vbat = power_get_vbat();
+    // If the voltage is greater than 4500 mV and less than 4750 it means its charging
+    if (vbat > 4500 && vbat < 4750) {
+        return true;
+    }
+    return false;
+}
+
+uint16_t power_get_ibat_charge(void) { return 0; }
+uint16_t power_get_ibat_discharge(void) { return 0; }
+uint16_t power_get_vusb(void) { return 0; }
+uint16_t power_get_iusb(void) { return 0; }
+uint16_t power_get_temp(void) { return 0; }
+
+bool usb_connected(void)
+{
+    // If the voltage is greater than 4500 mV it means USB is connected
+    uint16_t vbat = power_get_vbat();
+    if (vbat > 4500) {
+        return true;
+    }
+    return false;
+}