Allow setting the device start time

src/bluetooth.cpp

@@ -29,6 +29,8 @@ uint8_t* bluetoothDataBuffer;
 uint8_t* bluetoothResponse;
 size_t bluetoothDataCount = 0;
 
+RTC_DATA_ATTR uint32_t deviceStartTime = 0;
+
 void bluetoothStartAdvertising();
 void bluetoothDidReceiveData(uint8_t* buffer, uint16_t count);
 
@@ -169,6 +171,17 @@ enum class BluetoothRequest: uint8_t {
      *   This may happen when a new temperature recording is performed in between calls
      */
     clearRecordingBuffer = 2,
+
+    /**
+     * @brief Set the absolute start time of the device
+     * 
+     * Request:
+     * - Bytes 1-4: Number of seconds since 1970 (uint32_t)
+     * 
+     * Response: 
+     * - BluetoothResponse::success
+     */
+    setDeviceStartTime = 3,
 };
 
 enum class BluetoothResponse: uint8_t {
@@ -184,6 +197,9 @@ enum class BluetoothResponse: uint8_t {
     unknownCommand = 3,
 
     invalidNumberOfBytesToDelete = 4,
+
+    /* The request has not been completed yet */
+    responseInProgress = 5,
 };
 
 void setResponse(BluetoothResponse response) {
@@ -220,9 +236,6 @@ uint16_t readNumberFromReceivedBuffer(uint8_t* buffer) {
 void fillInfo() {
     uint16_t value;
 
-    // BluetoothResponse::success
-    setResponse(BluetoothResponse::success);
-
     // the number of bytes as a uint16_t (2 bytes)
     value = getTotalNumberOfStoredBytes();
     memcpy(bluetoothDataBuffer, &value, sizeof(uint16_t));
@@ -275,9 +288,16 @@ void fillInfo() {
     memcpy(bluetoothDataBuffer + bluetoothDataCount, &value, sizeof(uint16_t));
     bluetoothDataCount += sizeof(uint16_t);
 
+    // Total storage size of device
     value = totalStorageSize;
     memcpy(bluetoothDataBuffer + bluetoothDataCount, &value, sizeof(uint16_t));
     bluetoothDataCount += sizeof(uint16_t);
+
+    // Configured device start time
+    memcpy(bluetoothDataBuffer + bluetoothDataCount, &deviceStartTime, sizeof(uint32_t));
+    bluetoothDataCount += sizeof(uint32_t);
+
+    setResponse(BluetoothResponse::success);
 }
 
 void getRecordingData(uint8_t* buffer, uint16_t count) {
@@ -296,6 +316,7 @@ void getRecordingData(uint8_t* buffer, uint16_t count) {
     memcpy(&byteOffset, buffer + sizeof(uint16_t), sizeof(uint16_t));
     
     bluetoothDataCount = getRecordedBytesAtOffset(bluetoothDataBuffer, byteOffset, byteCount);
+    setResponseWithoutData(BluetoothResponse::success);
 }
 
 void clearRecordingBuffer(uint8_t* buffer, uint16_t count) {
@@ -314,24 +335,40 @@ void clearRecordingBuffer(uint8_t* buffer, uint16_t count) {
     setResponseWithoutData(BluetoothResponse::success);
 }
 
+void setDeviceStartTime(uint8_t* buffer, uint16_t count) {
+    if (count != sizeof(uint32_t)) {
+        setResponseWithoutData(BluetoothResponse::invalidCommand);
+        return;
+    }
+    memcpy(&deviceStartTime, buffer, sizeof(uint32_t));
+    setResponseWithoutData(BluetoothResponse::success);
+}
+
 void bluetoothDidReceiveData(uint8_t* buffer, uint16_t count) {
     if (count < 1) {
         setResponseWithoutData(BluetoothResponse::invalidCommand);
         return;
     }
+    setResponseWithoutData(BluetoothResponse::responseInProgress);
 
     BluetoothRequest request = static_cast<BluetoothRequest>(buffer[0]);
+    uint8_t* payload = buffer + sizeof(uint8_t);
+    uint16_t payloadSize = count - sizeof(uint8_t);
     switch (request) {
     case BluetoothRequest::getInfo:
         fillInfo();
         break;
 
     case BluetoothRequest::clearRecordingBuffer:
-        clearRecordingBuffer(buffer + sizeof(uint8_t), count - sizeof(uint8_t));
+        clearRecordingBuffer(payload, payloadSize);
         break;
 
     case BluetoothRequest::getRecordingData:
-        getRecordingData(buffer + sizeof(uint8_t), count - sizeof(uint8_t));
+        getRecordingData(payload, payloadSize);
+        break;
+
+    case BluetoothRequest::setDeviceStartTime:
+        setDeviceStartTime(payload, payloadSize);
         break;
     
     default: