init

esp32_readout/display.cpp

@@ -0,0 +1,37 @@
+#include "display.h"
+
+#include <Adafruit_SharpMem.h>
+
+Display::Display() {
+  this->_display = new Adafruit_SharpMem(SHARP_SCK, SHARP_MOSI, SHARP_SS, DISPLAY_HEIGHT, DISPLAY_WIDTH);
+
+  this->mid_x = DISPLAY_WIDTH / 2;
+  this->mid_y = DISPLAY_HEIGHT / 2;
+}
+
+void Display::setup() {
+  // start & clear the display
+  this->_display->begin();
+  this->_display->clearDisplay();
+  this->_display->setRotation(2);
+
+  this->_display->setTextColor(BLACK, WHITE);
+  this->_display->setTextSize(FONT_SIZE);
+  this->_display->setFont(FONT);
+
+  this->print("Smaage");
+}
+
+void Display::print(const char* text) {
+  this->_display->clearDisplay();
+  this->_display->setCursor(12, this->mid_x);
+  this->_display->println(text);
+  this->_display->refresh();
+}
+
+void Display::print_weight(double val) {
+  this->_display->clearDisplay();
+  this->_display->setCursor(12, this->mid_x);
+  this->_display->printf("%.2f g", val);
+  this->_display->refresh();
+}

esp32_readout/display.h

@@ -0,0 +1,25 @@
+
+#ifndef DISPLAY_DEF
+  #define DISPLAY_DEF
+
+  #include <Adafruit_GFX.h>
+  #include <Adafruit_SharpMem.h>
+  #include <string>
+
+  #include "env.h"
+
+  class Display {
+    private:
+      Adafruit_SharpMem* _display;
+
+      int mid_x;
+      int mid_y;
+    
+    public:
+      Display();
+      void setup();
+      void print(const char* text);
+      void print_weight(double weight);
+  };
+
+#endif

esp32_readout/env.h

@@ -0,0 +1,67 @@
+#ifndef ENV
+  #define ENV
+  #include <BLEDevice.h>
+  #include <BLEUtils.h>
+  #include <BLEScan.h>
+  #include <BLEAdvertisedDevice.h>
+
+  #include <Adafruit_NAU7802.h>
+  #include <Adafruit_GFX.h>
+  #include <Fonts/FreeSans9pt7b.h>
+
+  /********************* NAU7802 ****************************/
+
+  #define LDO NAU7802_3V3
+  #define GAIN NAU7802_GAIN_128
+  #define SPS NAU7802_RATE_20SPS
+
+  /****************************** DISPLAY *******************/
+
+  // any pins can be used
+  #define SHARP_SCK 7
+  #define SHARP_MOSI 9
+  #define SHARP_SS 44
+  #define DISPLAY_HEIGHT 144
+  #define DISPLAY_WIDTH 168
+  
+  #define BLACK 0
+  #define WHITE 1
+
+  #define FONT_SIZE 2
+  #define FONT &FreeSans9pt7b
+
+  /********************* BLE ********************************/
+
+  #define BLE true
+  #if BLE
+    #define SERVICE_UUID "9f0dfdb2-e978-494c-8f15-68dbe8d28672"
+    #define MILLIS_UUID "abb92561-a809-453c-8c7c-71d3fff5b86e"
+    #define WEIGHT_UUID "123e4567-e89b-12d3-a456-426614174000"
+  #endif
+
+  #if GAIN == NAU7802_GAIN_1
+    #define CALIBRATION_FACTOR 100.0 / 424.47
+
+  #elif GAIN == NAU7802_GAIN_2
+    #define CALIBRATION_FACTOR 100.0 / 2457.96
+
+  #elif GAIN == NAU7802_GAIN_4
+    #define CALIBRATION_FACTOR 100.0 / 3622.82
+
+  #elif GAIN == NAU7802_GAIN_8
+    #define CALIBRATION_FACTOR 100.0 / 6630.74
+
+  #elif GAIN == NAU7802_GAIN_16
+    #define CALIBRATION_FACTOR 100.0 / 13179.24
+
+  #elif GAIN == NAU7802_GAIN_32
+    #define CALIBRATION_FACTOR 100.0 / 25955.84
+
+  #elif GAIN == NAU7802_GAIN_64
+    #define CALIBRATION_FACTOR 100.0 / 52865.63
+
+  #elif GAIN == NAU7802_GAIN_128
+    #define CALIBRATION_FACTOR 100.0 / 104167.17
+  #endif
+
+#endif

esp32_readout/readout_test.ino

@@ -0,0 +1,121 @@
+#include "env.h"
+#include "display.h"
+
+Display display;
+Adafruit_NAU7802 nau;
+unsigned long _millis = 0;
+int32_t val = 0;
+#if BLE
+  BLEServer *pServer = NULL;
+  BLECharacteristic *millisCharacteristic = NULL;
+  BLECharacteristic *weightCharacteristic = NULL;
+  BLEAdvertising *pAdvertising = NULL;
+  bool deviceConnected = false;
+  bool oldDeviceConnected = false;
+
+  // Callback class to handle connection events
+  class MyServerCallbacks : public BLEServerCallbacks {
+    void onConnect(BLEServer* pServer) {
+      deviceConnected = true;
+      BLEDevice::startAdvertising();
+    }
+
+    void onDisconnect(BLEServer* pServer) {
+      deviceConnected = false;
+    }
+  };
+#endif
+
+void setup() {
+  Serial.begin(115200);
+  display.setup();
+
+  if (! nau.begin()) {
+    Serial.println("Failed to find NAU7802");
+    while (1) delay(10);  // Don't proceed.
+  }
+
+  nau.setLDO(LDO);
+  nau.setGain(GAIN);
+  nau.setRate(SPS);
+
+  // Take 10 readings to flush out readings
+  for (uint8_t i=0; i<10; i++) {
+    while (! nau.available()) delay(1);
+    nau.read();
+  }
+
+  while (! nau.calibrate(NAU7802_CALMOD_INTERNAL)) {
+    Serial.println("Failed to calibrate internal offset, retrying!");
+    delay(1000);
+  }
+
+  while (! nau.calibrate(NAU7802_CALMOD_OFFSET)) {
+    Serial.println("Failed to calibrate system offset, retrying!");
+    delay(1000);
+  }
+
+  #if BLE
+    // initialize the Bluetooth® Low Energy hardware
+    BLEDevice::init("Smaage");
+    pServer = BLEDevice::createServer();
+    pServer->setCallbacks(new MyServerCallbacks());
+    
+    BLEService *pService = pServer->createService(SERVICE_UUID);
+    
+    millisCharacteristic = pService->createCharacteristic(
+        MILLIS_UUID,
+        BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_NOTIFY
+    );
+    weightCharacteristic = pService->createCharacteristic(
+        WEIGHT_UUID,
+        BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_NOTIFY
+    );
+    millisCharacteristic->setValue((uint8_t *)&_millis, sizeof _millis);
+    weightCharacteristic->setValue((uint8_t *)&val, sizeof val);
+    pService->start();
+    
+    pAdvertising = BLEDevice::getAdvertising();
+    pAdvertising->addServiceUUID(SERVICE_UUID);
+    pAdvertising->setScanResponse(true);
+    BLEDevice::startAdvertising();
+    
+    Serial.println("BLE device is now advertising...");
+    Serial.print("BLE Address: ");
+    Serial.println(BLEDevice::getAddress().toString().c_str());
+  #endif
+
+  display.print("Smaage is ready!");
+}
+
+void loop() {
+  while (!nau.available()) {
+    delay(1);
+  }
+  val = nau.read();
+
+  #if BLE
+    if (deviceConnected) {
+      // Send the sensor reading
+      _millis = millis();
+      millisCharacteristic->setValue((uint8_t *)&_millis, sizeof _millis);
+      millisCharacteristic->notify();
+      weightCharacteristic->setValue((uint8_t *)&val, sizeof val);
+      weightCharacteristic->notify();
+    }
+    // disconnecting
+    if (!deviceConnected && oldDeviceConnected) {
+      delay(500);                   // give the bluetooth stack the chance to get things ready
+      pServer->startAdvertising();  // restart advertising
+      Serial.println("start advertising");
+      oldDeviceConnected = deviceConnected;
+    }
+    // connecting
+    if (deviceConnected && !oldDeviceConnected) {
+      // do stuff here on connecting
+      oldDeviceConnected = deviceConnected;
+    }
+  #else
+    Serial.print(millis()); Serial.print(","); Serial.println(val);
+  #endif
+}