fix a lot of low level cppcheck warnings (#9623)

* simplify the observer pattern, since all the called functions are const getters.
* use arduino macro over std: for numerical values and refactor local variables in drawScrollbar()
* oh, so Cppcheck actually complained about const pointers not being const.
* slowly getting out of ifdef hell
* fix inkHUD warnings as well
* last 2 check warnings
* git checks should fail on low defects from now on

src/modules/Telemetry/Sensor/AddI2CSensorTemplate.h

@@ -8,7 +8,7 @@
 
 static std::forward_list<TelemetrySensor *> sensors;
 
-template <typename T> void addSensor(ScanI2C *i2cScanner, ScanI2C::DeviceType type)
+template <typename T> void addSensor(const ScanI2C *i2cScanner, ScanI2C::DeviceType type)
 {
     ScanI2C::FoundDevice dev = i2cScanner->find(type);
     if (dev.type != ScanI2C::DeviceType::NONE || type == ScanI2C::DeviceType::NONE) {

src/modules/Telemetry/Sensor/PMSA003ISensor.cpp

@@ -86,7 +86,7 @@ bool PMSA003ISensor::getMetrics(meshtastic_Telemetry *measurement)
         return false;
     }
 
-    auto read16 = [](uint8_t *data, uint8_t idx) -> uint16_t { return (data[idx] << 8) | data[idx + 1]; };
+    auto read16 = [](const uint8_t *data, uint8_t idx) -> uint16_t { return (data[idx] << 8) | data[idx + 1]; };
 
     computedChecksum = 0;
 

src/modules/Telemetry/Sensor/SCD4XSensor.cpp

@@ -111,7 +111,7 @@ bool SCD4XSensor::getMetrics(meshtastic_Telemetry *measurement)
 
     bool dataReady;
     error = scd4x.getDataReadyStatus(dataReady);
-    if (!dataReady) {
+    if (error != SCD4X_NO_ERROR || !dataReady) {
 #if defined(SCD4X_I2C_CLOCK_SPEED) && defined(CAN_RECLOCK_I2C)
         reClockI2C(currentClock, _bus, false);
 #endif
@@ -419,7 +419,7 @@ bool SCD4XSensor::setTemperature(float tempReference)
     LOG_INFO("%s: Setting reference temperature at: %.2f", sensorName, tempReference);
 
     error = scd4x.getDataReadyStatus(dataReady);
-    if (!dataReady) {
+    if (error != SCD4X_NO_ERROR || !dataReady) {
         LOG_ERROR("%s: Data is not ready", sensorName);
         return false;
     }

src/modules/Telemetry/Sensor/SEN5XSensor.cpp

@@ -182,7 +182,7 @@ uint8_t SEN5XSensor::readBuffer(uint8_t *buffer, uint8_t byteNumber)
     return receivedBytes;
 }
 
-uint8_t SEN5XSensor::sen5xCRC(uint8_t *buffer)
+uint8_t SEN5XSensor::sen5xCRC(const uint8_t *buffer)
 {
     // This code is based on Sensirion's own implementation
     // https://github.com/Sensirion/arduino-core/blob/41fd02cacf307ec4945955c58ae495e56809b96c/src/SensirionCrc.cpp

src/modules/Telemetry/Sensor/SEN5XSensor.h

@@ -114,7 +114,7 @@ See: https://sensirion.com/resource/application_note/low_power_mode/sen5x
     bool sendCommand(uint16_t command);
     bool sendCommand(uint16_t command, uint8_t *buffer, uint8_t byteNumber = 0);
     uint8_t readBuffer(uint8_t *buffer, uint8_t byteNumber); // Return number of bytes received
-    uint8_t sen5xCRC(uint8_t *buffer);
+    uint8_t sen5xCRC(const uint8_t *buffer);
     bool startCleaning();
     uint8_t getMeasurements();
     // bool readRawValues();