Hello,
I am not done with working on this topic but here are my last codes that work for temperature and accelerometer. From now, I will start to work on the communication of a NanoBLE 33 sense with a Wio terminal to display the datas.
Peripheral
/*
* Device: Arduino Nano 33 BLE Sense
* Peripheral
* The values of the integrated temperature sensor and
* accelerometer are sent using BLE.
*/
#include <ArduinoBLE.h>
#include <Arduino_LSM9DS1.h> //accelerometer sensor
#include <Arduino_HTS221.h> // temperature sensor
int const d_a=2; //number of decimal to keep for the accelerometer
int const d_t=2; //number of decimal to keep for the temperature
//float values read by the sensor
float xSensor=0;
float ySensor=0;
float zSensor=0;
float tSensor=37;
//integer variables to send via BLE
int xBLE=xSensor*pow(10,d_a);
int yBLE=ySensor*pow(10,d_a);
int zBLE=zSensor*pow(10,d_a);
int tBLE=tSensor*pow(10,d_t);
//int t_i=t_f*100;
//int x_i=x_f*100;
//int y_i=y_f*100;
//int z_i=z_f*100;
BLEService SensorService("1101");
BLEUnsignedIntCharacteristic XChar("2101", BLERead | BLENotify);
BLEUnsignedIntCharacteristic YChar("2102", BLERead | BLENotify);
BLEUnsignedIntCharacteristic ZChar("2103", BLERead | BLENotify);
BLEUnsignedIntCharacteristic TChar("2104", BLERead | BLENotify);
void setup() {
IMU.begin();
HTS.begin();
Serial.begin(9600);
while (!Serial);
// if (!HTS.begin()){
// Serial.println("Failed to start the HTS221 sensor.");
// while(1);
//
// if (!IMU.begin()) {
// Serial.println("Failed to start the LSM9DS sensor.");
// while (1);
pinMode(LED_BUILTIN, OUTPUT);
if (!BLE.begin()) {
Serial.println("BLE failed to Initiate");
delay(500);
while (1);
}
BLE.setLocalName("Arduino XYZT (peripheral)");
BLE.setAdvertisedService(SensorService);
SensorService.addCharacteristic(XChar);
SensorService.addCharacteristic(YChar);
SensorService.addCharacteristic(ZChar);
SensorService.addCharacteristic(TChar);
BLE.addService(SensorService);
XChar.writeValue(xBLE);
YChar.writeValue(yBLE);
ZChar.writeValue(zBLE);
TChar.writeValue(tBLE);
BLE.advertise();
Serial.println("Arduino XYZT peripheral device is now active, waiting for connections...");
}
void loop() {
BLEDevice central = BLE.central();
if (central) {
Serial.print("Connected to central: ");
Serial.print("* Device MAC address: ");
Serial.println(central.address());
Serial.println(" ");
digitalWrite(LED_BUILTIN, HIGH);
while (central.connected()) {
//delay(200);
//read_sensor();
if (IMU.accelerationAvailable()) {
IMU.readAcceleration(xSensor, ySensor, zSensor);
}
tSensor=HTS.readTemperature();
Serial.print("xSensor ");
Serial.print(xSensor);
Serial.print(" - ySensor ");
Serial.print(ySensor);
Serial.print(" - zSensor ");
Serial.print(zSensor);
Serial.print(" - tSensor ");
Serial.println(tSensor);
Serial.println("");
xBLE=xSensor*pow(10,d_a);
yBLE=ySensor*pow(10,d_a);
zBLE=zSensor*pow(10,d_a);
tBLE=tSensor*pow(10,d_t);
//int t_i=t_f*100;
//int x_i=x_f*100;
//int y_i=y_f*100;
//int z_i=z_f*100;
//writeCharacteristicValue (Tchar, Xchar, Ychar, Zchar);
Serial.print("xBLE ");
Serial.print(xBLE);
Serial.print(" - yBLE ");
Serial.print(yBLE);
Serial.print(" - zBLE ");
Serial.print(zBLE);
Serial.print(" - tBLE ");
Serial.println(tBLE);
Serial.println("");
XChar.writeValue(xBLE);
YChar.writeValue(yBLE);
ZChar.writeValue(zBLE);
TChar.writeValue(tBLE);
//Serial.println("At Main Function");
Serial.print("XChar ");
Serial.print(XChar.value());
Serial.print(" - YChar ");
Serial.print(YChar.value());
Serial.print(" - ZChar ");
Serial.print(ZChar);
Serial.print(" - TChar ");
Serial.println(TChar.value());
Serial.println("");
Serial.println("");
//Serial.println("");
//Serial.println("");
delay(1000);
}
}
else {
delay(1000);
}
digitalWrite(LED_BUILTIN, LOW);
Serial.print("Disconnected from central: ");
Serial.println(central.address());
BLE.advertise();
}
//void read_sensor(){
//if (IMU.accelerationAvailable()) {
//IMU.readAcceleration(x_f, y_f, z_f);
//}
//t_f=HTS.readTemperature();
//
//Serial.print("x_f ");
//Serial.print(x_f);
//Serial.print(" - y_f ");
//Serial.print(y_f);
//Serial.print(" - z_f ");
//Serial.print(z_f);
//Serial.print(" - t_f ");
//Serial.println(t_f);
//Serial.println("");
////x_i=x_f*pow(10,d);
////y_i=y_f*pow(10,d);
////z_i=z_f*pow(10,d);
////t_i=t_f*pow(10,d);
//
//int t_i=t_f;
//int x_i=x_f;
//int y_i=y_f;
//int z_i=z_f;
//
//Serial.print("x_i ");
//Serial.print(x_i);
//Serial.print(" - y_i ");
//Serial.print(y_i);
//Serial.print(" - z_i ");
//Serial.print(z_i);
//Serial.print(" - t_i ");
//Serial.println(t_i);
//Serial.println("");
//}
Central
/*
BLE_Central_Device.ino
/*
* Device: Arduino Nano 33 BLE Sense
* Central
* The values of the integrated temperature sensor and
* accelerometer of another Nano 33 BLE are received using BLE.
*/
#include <ArduinoBLE.h>
void setup() {
Serial.begin(9600);
while (!Serial);
if (!BLE.begin()) {
Serial.println("* Starting BLE module failed!");
while (1);
}
BLE.setLocalName("Arduino XYZT (Central)");
Serial.println("Arduino XYZT (Central)");
Serial.println(" ");
//BLE.advertise();
}
void loop() {
BLE.scan();
BLEDevice peripheral = BLE.available();
//Serial.println("- Discovering peripheral device...");
// do
// {
// BLE.scanForUuid("1101");
// peripheral = BLE.available();
// } while (!peripheral);
if (peripheral) {
Serial.print("Found ");
Serial.print(peripheral.address());
Serial.print(" '");
Serial.print(peripheral.localName());
Serial.print("' ");
Serial.print(peripheral.advertisedServiceUuid());
Serial.println();
// Serial.println("* Peripheral device found!");
// Serial.print("* Device MAC address: ");
// Serial.println(peripheral.address());
// Serial.print("* Device name: ");
// Serial.println(peripheral.localName());
// Serial.print("* Advertised service UUID: ");
// Serial.println(peripheral.advertisedServiceUuid());
// Serial.println(" ");
//BLE.stopScan();
if (peripheral.localName() == "Arduino XYZT (peripheral)") {
// stop scanning
BLE.stopScan();
if (peripheral.connect()) {
Serial.println("Connected");
} else {
Serial.println("Failed to connect!");
return;
}
// discover peripheral attributes
Serial.println("Discovering attributes ...");
if (peripheral.discoverAttributes()) {
Serial.println("Attributes discovered");
} else {
Serial.println("Attribute discovery failed!");
peripheral.disconnect();
return;
}
// read and print device name of peripheral
Serial.println();
Serial.print("Device name: ");
Serial.println(peripheral.deviceName());
Serial.print("Appearance: 0x");
Serial.println(peripheral.appearance(), HEX);
Serial.println();
}
while (peripheral.connect()) {
//BLECharacteristic TChar = peripheral.characteristic( "2104" );
BLEService service = peripheral.service("1101");
Serial.print("Service ");
Serial.print(service.uuid());
//BLECharacteristic characteristic = service.characteristic("2104");
//readCharacteristicValue(characteristic);
BLECharacteristic Tchar = service.characteristic("2104");
//readCharacteristicValue(characteristic);
Serial.print("\tTemperature characteristic ");
Serial.print(Tchar.uuid());
// check if the characteristic is readable
if (Tchar.canRead()) {
//read the characteristic value
int16_t temperature = 0;
Tchar.readValue(&temperature,2);
Serial.print(", temperature = ");
Serial.println((float)temperature/100.0);
}
BLECharacteristic Xchar = service.characteristic("2101");
//readCharacteristicValue(characteristic);
Serial.print("\tX characteristic ");
Serial.print(Xchar.uuid());
// check if the characteristic is readable
if (Xchar.canRead()) {
//read the characteristic value
int32_t x = 0;
Xchar.readValue(&x,4);
Serial.print(", x = ");
Serial.println((float)x/100.0);
}
BLECharacteristic Ychar = service.characteristic("2102");
//readCharacteristicValue(characteristic);
Serial.print("\tY characteristic ");
Serial.print(Ychar.uuid());
// check if the characteristic is readable
if (Ychar.canRead()) {
//read the characteristic value
int32_t y = 0;
Ychar.readValue(&y,4);
Serial.print(", y = ");
Serial.println((float)y/100.0);
}
BLECharacteristic Zchar = service.characteristic("2103");
//readCharacteristicValue(characteristic);
Serial.print("\tZ characteristic ");
Serial.print(Zchar.uuid());
// check if the characteristic is readable
if (Zchar.canRead()) {
//read the characteristic value
int32_t z = 0;
Zchar.readValue(&z,4);
Serial.print(", z = ");
Serial.println((float)z/100.0);
}
delay(1000);
}
// } else {
// Serial.println("* Connection to peripheral device failed!");
// Serial.println(" ");
// return;
}
//Serial.println("Disconnected from peripheral: ");
}
void readCharacteristicValue(BLECharacteristic characteristic) {
// print the UUID and properties of the characteristic
Serial.print("\tCharacteristic ");
Serial.print(characteristic.uuid());
// check if the characteristic is readable
if (characteristic.canRead()) {
// read the characteristic value
characteristic.read();
if (characteristic.valueLength() > 0) {
Serial.print(", value = ");
//characteristic.value() returns byte array
unsigned long bitShiftData = 0;
bitShiftData = (uint32_t)characteristic.value()[3] << 24 | (uint32_t)characteristic.value()[2] << 16 | (uint32_t)characteristic.value()[1] << 8 | characteristic.value()[0];
Serial.println(bitShiftData, DEC);
Serial.print(bitShiftData / 100);
Serial.print('.');
if (bitShiftData % 100 < 10)
Serial.print('0');
Serial.println(bitShiftData % 100);
}
}
}
The peripheral code could be cleaner if I had managed to write a proper writeCharacteristicValue function.
Sometimes the reconnection works and sometimes it doesn't. Also sometimes the Attributes discovery fails, and the program stop so I still have to work to make it run until it works. I haven't tried to send the acceleration datas using floats yet.
I have 2 major issues so far:
- It takes around one second between each data to be sent with the bluetooth, eg about 1 measurement for each data (X, Y, Z, T) every 4 seconds. That is too slow for the acceleration for sure. I will try to figure out if just the information of the acceleration module is enough for our use so that only one data can be sent rather than 3 (but still need a better sampling rate).
- The distance range is very low : the 2 boards have to be very close from each other (less than 30 cm) to make the BLE communication work. I have these 2 links dealing with this problem and will explore that :
Clinical-Grade AFE with Integrated Measurement Systems for Synchronized Measurement of ECG, Heart Rate, SpO2, and Respiration Rate | Circuit Digest
BLE very weak signal - #30 by rakhiag
Another thing is that I get weird values with this part of the peripheral code, so I am not sure how the value function works.
Serial.print("XChar ");
Serial.print(XChar.value());
Serial.print(" - YChar ");
Serial.print(YChar.value());
Serial.print(" - ZChar ");
Serial.print(ZChar);
Serial.print(" - TChar ");
Serial.println(TChar.value());
Serial.println("");
Thanks again @cattledog, still have a lot to do but you have helped me a lot with this first step !