chg_en and safe battery temp logic

Author: sctanf

Kconfig

@@ -10,8 +10,13 @@ config USE_SLIMENRF_CONSOLE
     help
         Use basic console for commands.
 
+config BATTERY_CHARGER_HAS_NTC
+    bool "Battery thermistor"
+    help
+      Flag for battery NTC thermistor availability.
+
 choice
-	prompt "Battery voltage mapping"
+    prompt "Battery voltage mapping"
     default BATTERY_NO_MAPPING
 
 config BATTERY_USE_REG_BUCK_MAPPING
@@ -42,7 +47,7 @@ config BATTERY_LOW_RUNTIME_THRESHOLD
       If estimated runtime is not available, low battery will trigger under 10% estimated state of charge.
 
 choice
-	prompt "Status LED color mapping"
+    prompt "Status LED color mapping"
     default LED_TRI_COLOR
 
 config LED_RGB_COLOR
@@ -252,7 +257,7 @@ config USE_SENSOR_CLOCK
         Use external IMU clock if it is present.
 
 choice
-	prompt "Sensor fusion"
+    prompt "Sensor fusion"
     default SENSOR_USE_VQF
     help
         Select the sensor fusion method.
@@ -288,7 +293,6 @@ config RADIO_TX_POWER
 
 config CONNECTION_OVER_HID
     bool "Use HID for data output"
-    default n
     help
         Use HID if available.
         Otherwise, use ESB only.

src/system/power.c

@@ -42,6 +42,9 @@ static bool power_init = false;
 static bool device_plugged = false;
 static bool device_charged = false;
 
+static bool chg_temp_warn = false;
+static int64 last_valid_temp = -1;
+
 LOG_MODULE_REGISTER(power, LOG_LEVEL_INF);
 
 static void sys_WOM(bool force);
@@ -75,6 +78,12 @@ static const struct gpio_dt_spec ldo_en = GPIO_DT_SPEC_GET(ZEPHYR_USER_NODE, ldo
 #else
 #pragma message "LDO enable GPIO does not exist"
 #endif
+#if DT_NODE_HAS_PROP(ZEPHYR_USER_NODE, chg_en_gpios)
+#define CHG_EN_EXISTS true
+static const struct gpio_dt_spec chg_en = GPIO_DT_SPEC_GET(ZEPHYR_USER_NODE, chg_en_gpios);
+#else
+#pragma message "Charge enable GPIO does not exist"
+#endif
 
 #define ADAFRUIT_BOOTLOADER CONFIG_BUILD_OUTPUT_UF2
 
@@ -189,6 +198,30 @@ static void set_regulator(enum sys_regulator regulator)
 #endif
 }
 
+static int set_charger_enable(bool enable, bool plugged)
+{
+#if CHG_EN_EXISTS
+	static bool last_chg_en = false;
+	if (!plugged)
+		enable = false; // always disable charger if not plugged
+	if (enable != last_chg_en)
+	{
+		last_chg_en = enable;
+		gpio_pin_set_dt(&chg_en, enable);
+		LOG_INF("%s", enable ? "Enabled charger" : "Disabled charger");
+	}
+#elif CONFIG_BATTERY_CHARGER_HAS_NTC
+	// charger has implemented NTC and does not have enable pin, can ignore
+#else
+	if (!enable && plugged)
+	{
+		LOG_ERR("Cannot disable charger");
+		return -1;
+	}
+#endif
+	return 0;
+}
+
 static void wait_for_logging(void)
 {
 #if CONFIG_LOG_BACKEND_UART
@@ -463,6 +496,33 @@ static void power_thread(void)
 		bool charging = chg_read();
 		bool charged = stby_read();
 
+		float temp;
+		int chg_ret = sensor_get_sensor_temperature(&temp);
+		switch (chg_ret)
+		{
+		case -2:
+			last_valid_temp = -1;
+			chg_temp_warn = true;
+			break:
+		case -1:
+			if (last_valid_temp == -1)
+				last_valid_temp = k_uptime_get();
+			if (k_uptime_get() - last_valid_temp > 1000) // valid read timeout
+				chg_temp_warn = true;
+			break;
+		case 0:
+			last_valid_temp = k_uptime_get();
+			if (!chg_temp_warn && (temp < 5.f || temp > 45.f)) // this is still safe (hard limit is 0C, but that is dangerous)
+				chg_temp_warn = true;
+			else if (chg_temp_warn && temp > 10.f && temp < 40.f) // safest range
+				chg_temp_warn = false;
+		default:
+			break;
+		}
+		chg_ret = set_charger_enable(!chg_temp_warn, device_plugged);
+		// chg_ret = -1: outside safe temp range, but charger could not be disabled
+		// chg_ret = 0 and chg_temp_warn = true: out of temp range, charger is disabled or already has thermistor
+
 		int battery_mV;
 		int16_t battery_pptt = read_batt_mV(&battery_mV);
 		if (battery_level_pptt < 0)
@@ -543,7 +603,14 @@ static void power_thread(void)
 
 		connection_update_battery(battery_available, device_plugged, device_charged, calibrated_battery_pptt, battery_mV);
 
-		if (charging)
+		if (chg_ret)
+			set_led(SYS_LED_PATTERN_CRITICAL, SYS_LED_PRIORITY_CRITICAL);
+		else
+			set_led(SYS_LED_PATTERN_OFF, SYS_LED_PRIORITY_CRITICAL);
+
+		if (chg_temp_warn && plugged) // don't need to warn if not plugged in
+			set_led(SYS_LED_PATTERN_WARNING, SYS_LED_PRIORITY_SYSTEM); // not critical
+		else if (charging)
 			set_led(SYS_LED_PATTERN_PULSE_PERSIST, SYS_LED_PRIORITY_SYSTEM);
 		else if (charged)
 			set_led(SYS_LED_PATTERN_ON_PERSIST, SYS_LED_PRIORITY_SYSTEM);