rework sensor instantiation to saves memory by removing the static allocation

src/detect/ScanI2CConsumer.cpp

@@ -0,0 +1,16 @@
+#include "ScanI2CConsumer.h"
+#include <forward_list>
+
+static std::forward_list<ScanI2CConsumer *> ScanI2CConsumers;
+
+ScanI2CConsumer::ScanI2CConsumer()
+{
+    ScanI2CConsumers.push_front(this);
+}
+
+void ScanI2CCompleted(ScanI2C *i2cScanner)
+{
+    for (ScanI2CConsumer *consumer : ScanI2CConsumers) {
+        consumer->i2cScanFinished(i2cScanner);
+    }
+}

src/detect/ScanI2CConsumer.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "ScanI2C.h"
+#include <stddef.h>
+
+class ScanI2CConsumer
+{
+  public:
+    ScanI2CConsumer();
+    virtual void i2cScanFinished(ScanI2C *i2cScanner) = 0;
+};
+
+void ScanI2CCompleted(ScanI2C *i2cScanner);

src/detect/ScanI2CTwoWire.cpp

@@ -581,7 +581,7 @@ void ScanI2CTwoWire::scanPort(I2CPort port)
     scanPort(port, nullptr, 0);
 }
 
-TwoWire *ScanI2CTwoWire::fetchI2CBus(ScanI2C::DeviceAddress address) const
+TwoWire *ScanI2CTwoWire::fetchI2CBus(ScanI2C::DeviceAddress address)
 {
     if (address.port == ScanI2C::I2CPort::WIRE) {
         return &Wire;

src/detect/ScanI2CTwoWire.h

@@ -23,12 +23,12 @@ class ScanI2CTwoWire : public ScanI2C
 
     ScanI2C::FoundDevice find(ScanI2C::DeviceType) const override;
 
-    TwoWire *fetchI2CBus(ScanI2C::DeviceAddress) const;
-
     bool exists(ScanI2C::DeviceType) const override;
 
     size_t countDevices() const override;
 
+    static TwoWire *fetchI2CBus(ScanI2C::DeviceAddress);
+
   protected:
     FoundDevice firstOfOrNONE(size_t, DeviceType[]) const override;
 

src/main.cpp

@@ -23,6 +23,7 @@
 #include "power.h"
 
 #if !MESHTASTIC_EXCLUDE_I2C
+#include "detect/ScanI2CConsumer.h"
 #include "detect/ScanI2CTwoWire.h"
 #include <Wire.h>
 #endif
@@ -718,46 +719,21 @@ void setup()
     LOG_DEBUG("acc_info = %i", acc_info.type);
 #endif
 
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::BME_680, meshtastic_TelemetrySensorType_BME680);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::BME_280, meshtastic_TelemetrySensorType_BME280);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::BMP_280, meshtastic_TelemetrySensorType_BMP280);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::BMP_3XX, meshtastic_TelemetrySensorType_BMP3XX);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::BMP_085, meshtastic_TelemetrySensorType_BMP085);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::INA260, meshtastic_TelemetrySensorType_INA260);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::INA226, meshtastic_TelemetrySensorType_INA226);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::INA219, meshtastic_TelemetrySensorType_INA219);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::INA3221, meshtastic_TelemetrySensorType_INA3221);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::MAX17048, meshtastic_TelemetrySensorType_MAX17048);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::MCP9808, meshtastic_TelemetrySensorType_MCP9808);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::SHT31, meshtastic_TelemetrySensorType_SHT31);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::SHTC3, meshtastic_TelemetrySensorType_SHTC3);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::LPS22HB, meshtastic_TelemetrySensorType_LPS22);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::QMC6310, meshtastic_TelemetrySensorType_QMC6310);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::QMI8658, meshtastic_TelemetrySensorType_QMI8658);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::QMC5883L, meshtastic_TelemetrySensorType_QMC5883L);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::HMC5883L, meshtastic_TelemetrySensorType_QMC5883L);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::PMSA0031, meshtastic_TelemetrySensorType_PMSA003I);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::RCWL9620, meshtastic_TelemetrySensorType_RCWL9620);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::VEML7700, meshtastic_TelemetrySensorType_VEML7700);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::TSL2591, meshtastic_TelemetrySensorType_TSL25911FN);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::OPT3001, meshtastic_TelemetrySensorType_OPT3001);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::MLX90632, meshtastic_TelemetrySensorType_MLX90632);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::MLX90614, meshtastic_TelemetrySensorType_MLX90614);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::SHT4X, meshtastic_TelemetrySensorType_SHT4X);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::AHT10, meshtastic_TelemetrySensorType_AHT10);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::DFROBOT_LARK, meshtastic_TelemetrySensorType_DFROBOT_LARK);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::ICM20948, meshtastic_TelemetrySensorType_ICM20948);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::MAX30102, meshtastic_TelemetrySensorType_MAX30102);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::CGRADSENS, meshtastic_TelemetrySensorType_RADSENS);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::DFROBOT_RAIN, meshtastic_TelemetrySensorType_DFROBOT_RAIN);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::LTR390UV, meshtastic_TelemetrySensorType_LTR390UV);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::DPS310, meshtastic_TelemetrySensorType_DPS310);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::RAK12035, meshtastic_TelemetrySensorType_RAK12035);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::PCT2075, meshtastic_TelemetrySensorType_PCT2075);
     scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::SCD4X, meshtastic_TelemetrySensorType_SCD4X);
-    scannerToSensorsMap(i2cScanner, ScanI2C::DeviceType::TSL2561, meshtastic_TelemetrySensorType_TSL2561);
 
-    i2cScanner.reset();
 #endif
 
 #ifdef HAS_SDCARD
@@ -964,6 +940,12 @@ void setup()
     // Now that the mesh service is created, create any modules
     setupModules();
 
+#if !MESHTASTIC_EXCLUDE_I2C
+    // Inform modules about I2C devices
+    ScanI2CCompleted(i2cScanner.get());
+    i2cScanner.reset();
+#endif
+
     // warn the user about a low entropy key
     if (nodeDB->keyIsLowEntropy && !nodeDB->hasWarned) {
         LOG_WARN(LOW_ENTROPY_WARNING);