WIP: add NAU7802 based scale controller. (#4092)

* WIP: add NAU7802 based scale controller. Needs proto commit

* WIP: add NAU7802 based scale controller. Needs proto commit

* telemetry uses kg, scale internally g

* add sensor calibration setters

src/modules/Telemetry/Sensor/NAU7802Sensor.cpp

@@ -0,0 +1,143 @@
+#include "configuration.h"
+
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
+
+#include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "FSCommon.h"
+#include "NAU7802Sensor.h"
+#include "TelemetrySensor.h"
+#include <pb_decode.h>
+#include <pb_encode.h>
+
+meshtastic_Nau7802Config nau7802config = meshtastic_Nau7802Config_init_zero;
+
+NAU7802Sensor::NAU7802Sensor() : TelemetrySensor(meshtastic_TelemetrySensorType_NAU7802, "NAU7802") {}
+
+int32_t NAU7802Sensor::runOnce()
+{
+    LOG_INFO("Init sensor: %s\n", sensorName);
+    if (!hasSensor()) {
+        return DEFAULT_SENSOR_MINIMUM_WAIT_TIME_BETWEEN_READS;
+    }
+    status = nau7802.begin(*nodeTelemetrySensorsMap[sensorType].second);
+    nau7802.setSampleRate(NAU7802_SPS_320);
+    if (!loadCalibrationData()) {
+        LOG_ERROR("Failed to load calibration data\n");
+    }
+    nau7802.calibrateAFE();
+    LOG_INFO("Offset: %d, Calibration factor: %.2f\n", nau7802.getZeroOffset(), nau7802.getCalibrationFactor());
+    return initI2CSensor();
+}
+
+void NAU7802Sensor::setup() {}
+
+bool NAU7802Sensor::getMetrics(meshtastic_Telemetry *measurement)
+{
+    LOG_DEBUG("NAU7802Sensor::getMetrics\n");
+    nau7802.powerUp();
+    // Wait for the sensor to become ready for one second max
+    uint32_t start = millis();
+    while (!nau7802.available()) {
+        delay(100);
+        if (millis() - start > 1000) {
+            nau7802.powerDown();
+            return false;
+        }
+    }
+    // Check if we have correct calibration values after powerup
+    LOG_DEBUG("Offset: %d, Calibration factor: %.2f\n", nau7802.getZeroOffset(), nau7802.getCalibrationFactor());
+    measurement->variant.environment_metrics.weight = nau7802.getWeight() / 1000; // sample is in kg
+    nau7802.powerDown();
+    return true;
+}
+
+void NAU7802Sensor::calibrate(float weight)
+{
+    nau7802.calculateCalibrationFactor(weight * 1000, 64); // internal sample is in grams
+    if (!saveCalibrationData()) {
+        LOG_WARN("Failed to save calibration data\n");
+    }
+    LOG_INFO("Offset: %d, Calibration factor: %.2f\n", nau7802.getZeroOffset(), nau7802.getCalibrationFactor());
+}
+
+AdminMessageHandleResult NAU7802Sensor::handleAdminMessage(const meshtastic_MeshPacket &mp, meshtastic_AdminMessage *request,
+                                                           meshtastic_AdminMessage *response)
+{
+    AdminMessageHandleResult result;
+
+    switch (request->which_payload_variant) {
+    case meshtastic_AdminMessage_set_scale_tag:
+        if (request->set_scale == 0) {
+            this->tare();
+            LOG_DEBUG("Client requested to tare scale\n");
+        } else {
+            this->calibrate(request->set_scale);
+            LOG_DEBUG("Client requested to calibrate to %d kg\n", request->set_scale);
+        }
+        result = AdminMessageHandleResult::HANDLED;
+        break;
+
+    default:
+        result = AdminMessageHandleResult::NOT_HANDLED;
+    }
+
+    return result;
+}
+
+void NAU7802Sensor::tare()
+{
+    nau7802.calculateZeroOffset(64);
+    if (!saveCalibrationData()) {
+        LOG_WARN("Failed to save calibration data\n");
+    }
+    LOG_INFO("Offset: %d, Calibration factor: %.2f\n", nau7802.getZeroOffset(), nau7802.getCalibrationFactor());
+}
+
+bool NAU7802Sensor::saveCalibrationData()
+{
+    if (FSCom.exists(nau7802ConfigFileName) && !FSCom.remove(nau7802ConfigFileName)) {
+        LOG_WARN("Can't remove old state file\n");
+    }
+    auto file = FSCom.open(nau7802ConfigFileName, FILE_O_WRITE);
+    nau7802config.zeroOffset = nau7802.getZeroOffset();
+    nau7802config.calibrationFactor = nau7802.getCalibrationFactor();
+    bool okay = false;
+    if (file) {
+        LOG_INFO("%s state write to %s.\n", sensorName, nau7802ConfigFileName);
+        pb_ostream_t stream = {&writecb, &file, meshtastic_Nau7802Config_size};
+
+        if (!pb_encode(&stream, &meshtastic_Nau7802Config_msg, &nau7802config)) {
+            LOG_ERROR("Error: can't encode protobuf %s\n", PB_GET_ERROR(&stream));
+        } else {
+            okay = true;
+        }
+        file.flush();
+        file.close();
+    } else {
+        LOG_INFO("Can't write %s state (File: %s).\n", sensorName, nau7802ConfigFileName);
+    }
+    return okay;
+}
+
+bool NAU7802Sensor::loadCalibrationData()
+{
+    auto file = FSCom.open(nau7802ConfigFileName, FILE_O_READ);
+    bool okay = false;
+    if (file) {
+        LOG_INFO("%s state read from %s.\n", sensorName, nau7802ConfigFileName);
+        pb_istream_t stream = {&readcb, &file, meshtastic_Nau7802Config_size};
+        if (!pb_decode(&stream, &meshtastic_Nau7802Config_msg, &nau7802config)) {
+            LOG_ERROR("Error: can't decode protobuf %s\n", PB_GET_ERROR(&stream));
+        } else {
+            nau7802.setZeroOffset(nau7802config.zeroOffset);
+            nau7802.setCalibrationFactor(nau7802config.calibrationFactor);
+            okay = true;
+        }
+        file.close();
+    } else {
+        LOG_INFO("No %s state found (File: %s).\n", sensorName, nau7802ConfigFileName);
+    }
+    return okay;
+}
+
+#endif

src/modules/Telemetry/Sensor/NAU7802Sensor.h

@@ -0,0 +1,31 @@
+#include "MeshModule.h"
+#include "configuration.h"
+
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
+
+#include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "TelemetrySensor.h"
+#include <SparkFun_Qwiic_Scale_NAU7802_Arduino_Library.h>
+
+class NAU7802Sensor : public TelemetrySensor
+{
+  private:
+    NAU7802 nau7802;
+
+  protected:
+    virtual void setup() override;
+    const char *nau7802ConfigFileName = "/prefs/nau7802.dat";
+    bool saveCalibrationData();
+    bool loadCalibrationData();
+
+  public:
+    NAU7802Sensor();
+    virtual int32_t runOnce() override;
+    virtual bool getMetrics(meshtastic_Telemetry *measurement) override;
+    void tare();
+    void calibrate(float weight);
+    AdminMessageHandleResult handleAdminMessage(const meshtastic_MeshPacket &mp, meshtastic_AdminMessage *request,
+                                                meshtastic_AdminMessage *response) override;
+};
+
+#endif

src/modules/Telemetry/Sensor/TelemetrySensor.h

@@ -4,6 +4,7 @@
 
 #pragma once
 #include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "MeshModule.h"
 #include "NodeDB.h"
 #include <utility>
 
@@ -42,6 +43,12 @@ class TelemetrySensor
     virtual void setup();
 
   public:
+    virtual AdminMessageHandleResult handleAdminMessage(const meshtastic_MeshPacket &mp, meshtastic_AdminMessage *request,
+                                                        meshtastic_AdminMessage *response)
+    {
+        return AdminMessageHandleResult::NOT_HANDLED;
+    }
+
     bool hasSensor() { return nodeTelemetrySensorsMap[sensorType].first > 0; }
 
     virtual int32_t runOnce() = 0;