Read battery voltage on Minewsemi ME25LS01

Author: Normunds Gavars

src/helpers/nrf52/MinewsemiME25LS01Board.cpp

@@ -8,11 +8,12 @@ void MinewsemiME25LS01Board::begin() {
   // for future use, sub-classes SHOULD call this from their begin()
   startup_reason = BD_STARTUP_NORMAL;
   btn_prev_state = HIGH;
+  
+  pinMode(PIN_VBAT_READ, INPUT);
 
   sd_power_mode_set(NRF_POWER_MODE_LOWPWR);
 
 #ifdef BUTTON_PIN
-  // pinMode(BATTERY_PIN, INPUT);
   pinMode(BUTTON_PIN, INPUT);
   pinMode(LED_PIN, OUTPUT);
 #endif
@@ -31,7 +32,6 @@ void MinewsemiME25LS01Board::begin() {
   delay(10);   // give sx1262 some time to power up
 }
 
-#if 0
 static BLEDfu bledfu;
 
 static void connect_callback(uint16_t conn_handle) {
@@ -47,7 +47,7 @@ static void disconnect_callback(uint16_t conn_handle, uint8_t reason) {
 }
 
 
-bool TrackerT1000eBoard::startOTAUpdate(const char* id, char reply[]) {
+bool MinewsemiME25LS01Board::startOTAUpdate(const char* id, char reply[]) {
   // Config the peripheral connection with maximum bandwidth
   // more SRAM required by SoftDevice
   // Note: All config***() function must be called before begin()
@@ -58,7 +58,7 @@ bool TrackerT1000eBoard::startOTAUpdate(const char* id, char reply[]) {
   // Set max power. Accepted values are: -40, -30, -20, -16, -12, -8, -4, 0, 4
   Bluefruit.setTxPower(4);
   // Set the BLE device name
-  Bluefruit.setName("T1000E_OTA");
+  Bluefruit.setName("Minewsemi_OTA");
 
   Bluefruit.Periph.setConnectCallback(connect_callback);
   Bluefruit.Periph.setDisconnectCallback(disconnect_callback);
@@ -88,5 +88,4 @@ bool TrackerT1000eBoard::startOTAUpdate(const char* id, char reply[]) {
 
   strcpy(reply, "OK - started");
   return true;
-}
-#endif
+}

src/helpers/nrf52/MinewsemiME25LS01Board.h

@@ -16,9 +16,9 @@
 #define LR11X0_DIO_AS_RF_SWITCH  true
 #define LR11X0_DIO3_TCXO_VOLTAGE   1.6
 
-// built-ins
-//#define  PIN_VBAT_READ    5
-//#define  ADC_MULTIPLIER   (3 * 1.73 * 1000)
+#define  PIN_VBAT_READ BATTERY_PIN
+#define  ADC_MULTIPLIER   (1.815f) // dependent on voltage divider resistors. TODO: more accurate battery tracking
+
 
 class MinewsemiME25LS01Board : public mesh::MainBoard {
 protected:
@@ -28,43 +28,23 @@ class MinewsemiME25LS01Board : public mesh::MainBoard {
 public:
   void begin();
 
+#define BATTERY_SAMPLES 8
+
   uint16_t getBattMilliVolts() override {
-  #ifdef BATTERY_PIN
-   #ifdef PIN_3V3_EN
-    digitalWrite(PIN_3V3_EN, HIGH);
-   #endif
-    analogReference(AR_INTERNAL_3_0);
     analogReadResolution(12);
-    delay(10);
-    float volts = (analogRead(BATTERY_PIN) * ADC_MULTIPLIER * AREF_VOLTAGE) / 4096;
-   #ifdef PIN_3V3_EN
-    digitalWrite(PIN_3V3_EN, LOW);
-   #endif
-
-    analogReference(AR_DEFAULT);  // put back to default
-    analogReadResolution(10);
-
-    return volts * 1000;
-  #else
-    return 0;
-  #endif
+
+    uint32_t raw = 0;
+    for (int i = 0; i < BATTERY_SAMPLES; i++) {
+      raw += analogRead(PIN_VBAT_READ);
+    }
+    raw = raw / BATTERY_SAMPLES;
+    return (ADC_MULTIPLIER * raw);
   }
 
   uint8_t getStartupReason() const override { return startup_reason; }
 
   const char* getManufacturerName() const override {
-    return "m25ls01";
-  }
-
-  int buttonStateChanged() {
-  #ifdef BUTTON_PIN
-    uint8_t v = digitalRead(BUTTON_PIN);
-    if (v != btn_prev_state) {
-      btn_prev_state = v;
-      return (v == LOW) ? 1 : -1;
-    }
-  #endif
-    return 0;
+    return "Minewsemi";
   }
 
   void powerOff() override {
@@ -81,10 +61,6 @@ class MinewsemiME25LS01Board : public mesh::MainBoard {
         digitalWrite(BUZZER_EN, LOW);
     #endif
 
-    #ifdef PIN_3V3_EN
-        digitalWrite(PIN_3V3_EN, LOW);
-    #endif
-
     #ifdef LED_PIN
     digitalWrite(LED_PIN, LOW);
     #endif
@@ -108,5 +84,5 @@ class MinewsemiME25LS01Board : public mesh::MainBoard {
     NVIC_SystemReset();
   }
 
-//  bool startOTAUpdate(const char* id, char reply[]) override;
+  bool startOTAUpdate(const char* id, char reply[]) override;
 };

variants/minewsemi_me25ls01/platformio.ini

@@ -8,7 +8,6 @@ build_flags = ${nrf52_base.build_flags}
   -I lib/nrf52/s140_nrf52_7.3.0_API/include/nrf52
 lib_ignore =
   BluetoothOTA
-  lvgl
   lib5b4
 lib_deps =
   ${nrf52_base.lib_deps}
@@ -67,7 +66,6 @@ build_flags = ${me25ls01.build_flags}
   ;-D PIN_BUZZER_EN=37      
 build_src_filter = ${me25ls01.build_src_filter}
   +<helpers/nrf52/SerialBLEInterface.cpp>
-  ;+<helpers/ui/buzzer.cpp>
   +<../examples/companion_radio/*.cpp>
 lib_deps = ${me25ls01.lib_deps}
   adafruit/RTClib @ ^2.1.3
@@ -92,9 +90,6 @@ build_flags = ${me25ls01.build_flags}
   -D MAX_NEIGHBOURS=8
   -D DISPLAY_CLASS=NullDisplayDriver
 build_src_filter = ${me25ls01.build_src_filter}
-  ;+<helpers/nrf52/SerialBLEInterface.cpp>
-  ;+<helpers/ui/buzzer.cpp>
-  ;+<../examples/companion_radio/*.cpp>
   +<../examples/simple_repeater>
 lib_deps = ${me25ls01.lib_deps}
   adafruit/RTClib @ ^2.1.3
@@ -121,10 +116,6 @@ build_flags = ${me25ls01.build_flags}
   -D MAX_NEIGHBOURS=8
   -D DISPLAY_CLASS=NullDisplayDriver
 build_src_filter = ${me25ls01.build_src_filter}
-  ;+<helpers/nrf52/SerialBLEInterface.cpp>
-  ;+<helpers/ui/buzzer.cpp>
-  ;+<../examples/companion_radio/*.cpp>
-  ;+<../examples/simple_repeater>
   +<../examples/simple_room_server>
 lib_deps = ${me25ls01.lib_deps}
   adafruit/RTClib @ ^2.1.3
@@ -149,11 +140,6 @@ build_flags = ${me25ls01.build_flags}
   -D MAX_NEIGHBOURS=8
   -D DISPLAY_CLASS=NullDisplayDriver
 build_src_filter = ${me25ls01.build_src_filter}
-  ;+<helpers/nrf52/SerialBLEInterface.cpp>
-  ;+<helpers/ui/buzzer.cpp>
-  ;+<../examples/companion_radio/*.cpp>
-  ;+<../examples/simple_repeater>
-  ;+<../examples/simple_room_server>
   +<../examples/simple_secure_chat/main.cpp>
 lib_deps = ${me25ls01.lib_deps}
   adafruit/RTClib @ ^2.1.3
@@ -173,11 +159,6 @@ build_flags = ${me25ls01.build_flags}
   -D DISPLAY_CLASS=NullDisplayDriver
 build_src_filter = ${me25ls01.build_src_filter}
   +<helpers/nrf52/*.cpp>
-  ;+<helpers/nrf52/SerialBLEInterface.cpp>
-  ;+<helpers/ui/buzzer.cpp>
-  ;+<../examples/companion_radio/*.cpp>
-  ;+<../examples/simple_repeater>
-  ;+<../examples/simple_room_server>
   +<../examples/companion_radio>
 lib_deps = ${me25ls01.lib_deps}
   adafruit/RTClib @ ^2.1.3

variants/minewsemi_me25ls01/variant.cpp

@@ -35,7 +35,7 @@ const uint32_t g_ADigitalPinMap[PINS_COUNT + 1] =
   28, // P0.28
   29, // P0.29, 
   30, // P0.30
-  31, // P0.31, 
+  31, // P0.31, BATTERY_PIN
   32, // P1.00
   33, // P1.01, LORA_DIO_1
   34, // P1.02
@@ -60,8 +60,8 @@ void initVariant()
   pinMode(BATTERY_PIN, INPUT);
   pinMode(PIN_BUTTON1, INPUT);
 
-  pinMode(PIN_3V3_EN, OUTPUT);
-  pinMode(PIN_3V3_ACC_EN, OUTPUT);
+  // pinMode(PIN_3V3_EN, OUTPUT);
+  // pinMode(PIN_3V3_ACC_EN, OUTPUT);
   pinMode(LED_PIN, OUTPUT);
   pinMode(P_LORA_TX_LED, OUTPUT);
 

variants/minewsemi_me25ls01/variant.h

@@ -2,26 +2,19 @@
 
 #include "WVariant.h"
 
-////////////////////////////////////////////////////////////////////////////////
 // Low frequency clock source
-
 #define USE_LFXO    // 32.768 kHz crystal oscillator
 #define VARIANT_MCK (64000000ul)
 // #define USE_LFRC    // 32.768 kHz RC oscillator
 
 // Power
-#define PIN_3V3_EN              (32 + 5)            // P1.6 Power to Sensors
-#define PIN_3V3_ACC_EN          -1
-
-#define BATTERY_PIN             (-1)             // P0.2/AIN0
+#define BATTERY_PIN             (31)
 #define BATTERY_IMMUTABLE
 #define ADC_MULTIPLIER          (2.0F)
 
 #define ADC_RESOLUTION          (14)
 #define BATTERY_SENSE_RES       (12)
 
-#define AREF_VOLTAGE            (3.0)
-
 // Number of pins
 #define PINS_COUNT              (48)
 #define NUM_DIGITAL_PINS        (48)