Hey, what's up, Guys! Akarsh here from CETech.

In this tutorial, I'm going to show you how to trigger actions with Bluetooth using M5Stamp PICO and M5Stick C which are very cheap and High efficient ESP32 Controllers.

Components Required:

• M5Stick C
• M5Stamp PICO

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#include <M5StickC.h>
#include "BLEDevice.h"
#include "BLEUtils.h"
#include "BLEServer.h"
#include "BLEBeacon.h"

BLEAdvertising *pAdvertising;   // BLE Advertisement type
struct timeval now;
#define GPIO_DEEP_SLEEP_DURATION     1  // sleep x seconds and then wake up
RTC_DATA_ATTR static time_t last;        // remember last boot in RTC Memory
RTC_DATA_ATTR static uint32_t bootcount; // remember number of boots in RTC Memory
#define BEACON_UUID "87b99b2c-90fd-11e9-bc42-526af7764f64" // UUID 1 128-Bit (may use linux tool uuidgen or random numbers via https://www.uuidgenerator.net/)
void setBeacon()
{
  BLEBeacon oBeacon = BLEBeacon();  oBeacon.setManufacturerId(0x4C00);   oBeacon.setProximityUUID(BLEUUID(BEACON_UUID));  oBeacon.setMajor((bootcount & 0xFFFF0000) >> 16);  oBeacon.setMinor(bootcount & 0xFFFF);  BLEAdvertisementData oAdvertisementData = BLEAdvertisementData();  BLEAdvertisementData oScanResponseData = BLEAdvertisementData();
  oAdvertisementData.setFlags(0x04); // BR_EDR_NOT_SUPPORTED 0x04
  std::string strServiceData = "";
  strServiceData += (char)26;     // Len  strServiceData += (char)0xFF;   // Type  strServiceData += oBeacon.getData();  oAdvertisementData.addData(strServiceData);
  pAdvertising->setAdvertisementData(oAdvertisementData);  pAdvertising->setScanResponseData(oScanResponseData);
}

void setup() {  M5.begin();  Serial.begin(115200);  M5.Lcd.setTextColor(YELLOW);  //Set the font color to yellow.  设置字体颜色为黄色  M5.Lcd.setRotation(3);  M5.Axp.ScreenBreath(10);  M5.Lcd.setTextColor(RED);  M5.Lcd.setCursor(3, 10);  M5.Lcd.setTextSize(2);
}

void loop() {
  M5.update();  M5.Lcd.setCursor(3, 10);  if (M5.BtnA.wasReleased()) {    M5.Lcd.setTextColor(GREEN);    M5.Lcd.println("Triggred");    Serial.println("Trigger mode");    // Create the BLE Device    BLEDevice::init("BLE Receiver 01");    // Create the BLE Server    BLEServer *pServer = BLEDevice::createServer(); // <-- no longer required to instantiate BLEServer, less flash and ram usage    pAdvertising = BLEDevice::getAdvertising();    BLEDevice::startAdvertising();    setBeacon();    // Start advertising    pAdvertising->start();    Serial.println("Advertizing started...");    delay(1000);    pAdvertising->stop();    M5.Lcd.fillScreen(BLACK);      M5.Lcd.setCursor(3, 10);  }   }

Upload the above code to your M5Stick C Controller.

#include "Arduino.h"
#include <FastLED.h>
#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEScan.h>
#include <BLEAdvertisedDevice.h>

// How many leds in your strip?
#define NUM_LEDS 1
#define DATA_PIN 27

// Define the array of leds
CRGB leds[NUM_LEDS];

String knownBLEAddresses[] = {"24:a1:60:53:06:3e"};
int RSSI_THRESHOLD = -100;
bool device_found;
int scanTime = 1; //In seconds
BLEScan* pBLEScan;
class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {    void onResult(BLEAdvertisedDevice advertisedDevice) {      for (int i = 0; i < (sizeof(knownBLEAddresses) / sizeof(knownBLEAddresses[0])); i++)      {        if (strcmp(advertisedDevice.getAddress().toString().c_str(), knownBLEAddresses[i].c_str()) == 0)        {          device_found = true;          break;        }        else          device_found = false;      }      Serial.printf("Advertised Device: %s \n", advertisedDevice.toString().c_str());    }
};
void setup() {  Serial.begin(115200); //Enable UART on ESP32  FastLED.addLeds<SK6812, DATA_PIN, RGB>(leds, NUM_LEDS);  // GRB ordering is typical  Serial.println("Scanning..."); // Print Scanning  BLEDevice::init("");  pBLEScan = BLEDevice::getScan(); //create new scan  pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks()); //Init Callback Function  pBLEScan->setActiveScan(true); //active scan uses more power, but get results faster  pBLEScan->setInterval(100); // set Scan interval  pBLEScan->setWindow(99);  // less or equal setInterval value
}
void loop()
{  BLEScanResults foundDevices = pBLEScan->start(scanTime, false);
  for (int i = 0; i < foundDevices.getCount(); i++)  {    BLEAdvertisedDevice device = foundDevices.getDevice(i);    int rssi = device.getRSSI();    Serial.print("RSSI: ");    Serial.println(rssi);    if (rssi > RSSI_THRESHOLD && device_found == true)    {      Serial.println("Triggred");      leds[0] = 0xf00000;      FastLED.show();      delay(200);    }
  }  // Now turn the LED off, then pause  leds[0] = 0x00f000;  FastLED.show();  delay(200);  pBLEScan->clearResults();   // delete results fromBLEScan buffer to release memory
}

In the above code, you have to change the BLE Address of your M5Stick C.

Here I have added my M5Stick C's BLE Address. Change this according to yours.

Once the Transmitter and Receiver codes have been uploaded to the M5Stick and M5Stamp, connect the M5Stamp to your PC and open the serial monitor, then click the button A on the M5Stick C, which will display Triggered on the TFT Display.

Check the Serial Monitor Results whenever you see a triggered message in your M5Stick C.

The name of the ESP Transmitter, RSSI, and Triggered Message will be displayed on the serial monitor. The Green led on the M5Stamp will blink.

The Green led will blink every time the button is pressed.