esp32lorabridge

V1.0

ESP32 Lora Bridge

power USB
wireless lora
sensor lprf
mcu esp32
status ongoing

Features

  • Get GPS location every 90 seconds
  • Display the GPS data on e-ink
  • Ping the GPS location to the other node device via LoRa every 60 seconds
  • Display the GPS data on e-ink for self and other node
  • Display the calculated distance between 2 GPS locations

Firmware

Download code
#define DEBUG

#include "DebugUtils.h"

#include "src/lora/lora.h"
#include "src/eink/eink.h"
#include "src/gps/gps.h"

long lastSendTime = 0;
int interval = 2000;

int count = 0;
char count_string[] = {'0', '0', '0','\0'};

void setup() {
  #ifdef DEBUG
  SerialUSB.begin(9600);
  while (!SerialUSB) { }
  #endif

  DEBUG_TITLE("Start Oak: With GPS, LoRa and E-ink...");

  if(!initLora()) {
    DEBUG_PRINT("LoRa init failed. Check your connections.");
  }

  // initGPS();
}

void loop() {
  if (millis() - lastSendTime > interval) {
    // count
    sprintf(count_string, "%d", ++count);
    DEBUG_PRINT(count_string);
    String sensorData = String(count);

    // E-ink
    if (!initEink()) {
      DEBUG_TITLE("E-ink initialization failed");
    }

    clearEink();
    setEink();
    displayEink(0, 50, count_string);

    // LoRa send
    sendMessage(sensorData);

    lastSendTime = millis();
    interval = random(2000) + 1000;
  }

  // LoRa receive
  receiveMessage();
}

Makefile

BOARD?=arduino:samd:mzero_bl
PORT := $(shell ls /dev/cu.usbmodem*)

.PHONY: default lint all flash clean

default: all flash clean

lint:
	cpplint --extensions=ino --filter=-legal/copyright *.ino

all:
	arduino-cli compile --fqbn $(BOARD) ./

flash:
	arduino-cli upload -p $(PORT) --fqbn $(BOARD)

clean:
	rm -r build

Serial console

Firmware serial console

Test

Download test code
#include <bluefruit.h>
#include "Adafruit_VEML6075.h"

int redPin = PIN_A1;
int greenPin = PIN_A2;
int bluePin = PIN_A3;

const int ENSensorPin = 15;
Adafruit_VEML6075 uv = Adafruit_VEML6075();
uint8_t  uvindexvalue = 0x42;
float  readUVIndexValue = 0.0;

/* GATT Services https://www.bluetooth.com/specifications/gatt/services/
    Name: Environmental Sensing
    Uniform Type Identifier: org.bluetooth.service.environmental_sensing
    Assigned Number: 0x181A
    Specification: GSS
*/
#define UUID16_SVC_ENVIRONMENTAL_SENSING 0x181A

/* GATT Characteristics https://www.bluetooth.com/specifications/gatt/characteristics/
    Name: UV Index
    Uniform Type Identifier: org.bluetooth.characteristic.uv_index
    Assigned Number: 0x2A76
    Specification: GSS
*/
#define UUID16_CHR_UV_INDEX 0x2A76

BLEService        ess = BLEService(UUID16_SVC_ENVIRONMENTAL_SENSING);
BLECharacteristic uvic = BLECharacteristic(UUID16_CHR_UV_INDEX);

BLEDis bledis;    // DIS (Device Information Service) helper class instance

// Advanced function prototypes
void startAdv(void);
void setupESService(void);
void connect_callback(uint16_t conn_handle);
void disconnect_callback(uint16_t conn_handle, uint8_t reason);

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10);
  pinMode(ENSensorPin, OUTPUT);
  digitalWrite(ENSensorPin, LOW);

  Serial.println("Starting Palm design verification test");
  Serial.println("-------------------------------------\n");

  Serial.println("Test 1/14: It expects display GREEN LED");
  displayLEDColor(0, 255, 0);
  delay(1000);

  Serial.println("Test 2/14: It expects display YELLOW LED");
  displayLEDColor(255, 255, 0);
  delay(1000);

  Serial.println("Test 3/14: It expects display ORANGE LED");
  displayLEDColor(255, 50, 0);
  delay(1000);

  Serial.println("Test 4/14: It expects display RED LED");
  displayLEDColor(255, 0, 0);
  delay(1000);

  Serial.println("Test 5/14: It expects display PURPLE LED");
  displayLEDColor(255, 0, 255);
  delay(1000);

  Serial.println("Test 6/14: It expects display no color on the LED");
  displayLEDColor(0, 0, 0);
  delay(1000);

  digitalWrite(ENSensorPin, HIGH);
  Serial.println("Test 7/14: It expects the Sensor VEML6075 to be disabled");
  delay(1000);

  digitalWrite(ENSensorPin, LOW);
  delay(100);

  int returnValue = uv.begin();
  if (!returnValue) {
    Serial.println("Test 8/14: It expects to error if sensor is not found");
  }
  Serial.println("Test 9/14: It expects the Sensor VEML6075 to be enabled");

  Serial.println("Test 10/14: It expects to initialise the nRF52 module");
  Bluefruit.begin();
  Bluefruit.setName("TestPalm@Hutscape");

  Bluefruit.Periph.setConnectCallback(connect_callback);
  Bluefruit.Periph.setDisconnectCallback(disconnect_callback);

  bledis.setManufacturer("Adafruit Industries");
  bledis.setModel("Bluefruit Feather52");
  bledis.begin();;
  setupESService();
  startAdv();

  Serial.println("Test 11/14: It expects to start advertising");
}

void loop() {
  digitalToggle(LED_RED);  // blinking RED LED indicates reading UV sensor

  readUVIndexValue = uv.readUVI();
  uvindexvalue = round(abs(readUVIndexValue));

  Serial.print("Test 12/14: It expects to read UV Index value: ");
  Serial.println(uvindexvalue);
  displayLED(uvindexvalue);

  if (Bluefruit.connected()) {
    // Note: We use .indicate instead of .write!
    // If it is connected but CCCD is not enabled
    // The characteristic's value is still updated although indicate is not sent
    if (uvic.indicate(&uvindexvalue, sizeof(uvindexvalue))) {
      Serial.print("Test 13/14: It expects to update UV Index value: ");
      Serial.println(uvindexvalue);
    } else {
      Serial.println("Test 14/14: It errors when indicate is not set");
    }
  }

  delay(2000);
}

void displayLEDColor(int red, int green, int blue) {
  analogWrite(redPin, red);
  analogWrite(greenPin, green);
  analogWrite(bluePin, blue);
}

void displayLED(uint8_t uvindexvalue) {
  if (uvindexvalue <= 2) {
    // UV Index <= 2, display GREEN or no color alerts
    displayLEDColor(0, 255, 0);
  } else if (uvindexvalue >= 3 && uvindexvalue <= 5) {
    // UV Index is from 3 to 5, display YELLOW
    displayLEDColor(255, 255, 0);
  } else if (uvindexvalue >= 6 && uvindexvalue <= 7) {
    // UV Index is from 6 to 7, display ORANGE
    displayLEDColor(255, 50, 0);
  } else if (uvindexvalue >= 8 && uvindexvalue <= 10) {
    // UV Index is from 8 to 10, display RED
    displayLEDColor(255, 0, 0);
  } else {
    // UV Index is above 11, display PURPLE
    displayLEDColor(255, 0, 255);
  }
}

void startAdv(void) {
  // Advertising packet
  Bluefruit.Advertising.addFlags(BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE);
  Bluefruit.Advertising.addTxPower();

  // Include HTM Service UUID
  Bluefruit.Advertising.addService(ess);

  // Include Name
  Bluefruit.Advertising.addName();

  /* Start Advertising
   * - Enable auto advertising if disconnected
   * - Interval:  fast mode = 20 ms, slow mode = 152.5 ms
   * - Timeout for fast mode is 30 seconds
   * - Start(timeout) with timeout = 0 will advertise forever (until connected)
   *
   * For recommended advertising interval
   * https://developer.apple.com/library/content/qa/qa1931/_index.html
   */
  Bluefruit.Advertising.restartOnDisconnect(true);

  // in unit of 0.625 ms
  Bluefruit.Advertising.setInterval(32, 244);

  // number of seconds in fast mode
  Bluefruit.Advertising.setFastTimeout(30);

  // 0 = Don't stop advertising after n seconds
  Bluefruit.Advertising.start(0);
}

void setupESService(void) {
  // Configure the Environmental Sensing service
  // See: https://www.bluetooth.com/wp-content/uploads/Sitecore-Media-Library/Gatt/Xml/Characteristics/org.bluetooth.characteristic.uv_index.xml
  // Supported Characteristics:
  // Name                         UUID    Requirement Properties
  // ---------------------------- ------  ----------- ----------
  // UV Index                     0x2A76  Mandatory   Read
  ess.begin();

  // Note: You must call .begin() on the BLEService before calling .begin() on
  // any characteristic(s) within that service definition.. Calling .begin() on
  // a BLECharacteristic will cause it to be added to the last BLEService that
  // was 'begin()'ed!

  // Configure the UV Index characteristic
  // See:https://www.bluetooth.com/wp-content/uploads/Sitecore-Media-Library/Gatt/Xml/Characteristics/org.bluetooth.characteristic.uv_index.xml
  // Properties = Indicate
  // Min Len    = 1
  // Max Len    = 1
  // B0         = UINT8 - UV Index measurement unitless
  uvic.setProperties(CHR_PROPS_INDICATE);
  uvic.setPermission(SECMODE_OPEN, SECMODE_NO_ACCESS);
  uvic.setFixedLen(1);
  uvic.setCccdWriteCallback(cccd_callback);  // Optionally capture CCCD updates
  uvic.begin();
  uvic.write(&uvindexvalue, sizeof(uvindexvalue));
}

void connect_callback(uint16_t conn_handle) {
  // Get the reference to current connection
  BLEConnection* connection = Bluefruit.Connection(conn_handle);

  char central_name[32] = { 0 };
  connection->getPeerName(central_name, sizeof(central_name));

  Serial.print("Connected to ");
  Serial.println(central_name);
}

/**
 * Callback invoked when a connection is dropped
 * @param conn_handle connection where this event happens
 * @param reason is a BLE_HCI_STATUS_CODE which can be found in ble_hci.h
 */
void disconnect_callback(uint16_t conn_handle, uint8_t reason) {
  (void) conn_handle;
  (void) reason;

  Serial.println("Disconnected");
  Serial.println("Advertising!");
}

void cccd_callback(uint16_t conn_hdl,
  BLECharacteristic* chr, uint16_t cccd_value) {
    // Display the raw request packet
    Serial.print("CCCD Updated: ");

    // Serial.printBuffer(request->data, request->len);
    Serial.print(cccd_value);
    Serial.println("");

    // Check the characteristic this CCCD update is associated with in case
    // this handler is used for multiple CCCD records.
    if (chr->uuid == uvic.uuid) {
        if (chr->indicateEnabled(conn_hdl)) {
            Serial.println("UV Index Measurement 'Indicate' enabled");
        } else {
            Serial.println("UV Index Measurement 'Indicate' disabled");
        }
    }
}

Makefile

.PHONY: lint compile upload clean

lint:
	cpplint --extensions=ino --filter=-legal/copyright *.ino

compile:
	arduino-cli compile --fqbn adafruit:nrf52:feather52832 ./

upload:
	adafruit-nrfutil dfu genpkg --dev-type 0x0052 --application ./.*.hex dfu-package.zip
	adafruit-nrfutil dfu serial --package dfu-package.zip -p /dev/tty.SLAB_USBtoUART -b 115200

clean:
	rm -f .*.elf
	rm -f .*.hex
	rm -f *.zip

flash: lint compile upload clean

Serial console

Firmware serial console