This exercise implement Python 3 code run on Raspberry Pi act as BLE Central,
connect to Arduino Nano RP2040 Connect act as BLE Peripheral. And send data
(0x01/0x00) to turn the Nano RP2040 Connect's onboard LED ON/OFF.
Arduino Nano RP2040 Connect act as BLE Peripheral side:
- Make sure ArduinoBLE library is installed.
- The Arduino code is modified from ArduinoBLE Examples > Peripheral >
CallbackLED. With MAC, Service UUID, Characteristic UUID, and BLE written data
displayed. Such that we can program Central side accordingly.
nanoRP2040_BLE_CallbackLED.ino
/*
Callback LED
This example creates a BLE peripheral with service that contains a
characteristic to control an LED. The callback features of the
library are used.
The circuit:
- Arduino MKR WiFi 1010, Arduino Uno WiFi Rev2 board, Arduino Nano 33 IoT,
Arduino Nano 33 BLE, or Arduino Nano 33 BLE Sense board.
You can use a generic BLE central app, like LightBlue (iOS and Android) or
nRF Connect (Android), to interact with the services and characteristics
created in this sketch.
This example code is in the public domain.
*/
#include <ArduinoBLE.h>
BLEService ledService("19B10000-E8F2-537E-4F6C-D104768A1214"); // create service
// create switch characteristic and allow remote device to read and write
BLEByteCharacteristic switchCharacteristic("19B10001-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);
const int ledPin = LED_BUILTIN; // pin to use for the LED
void setup() {
Serial.begin(9600);
while (!Serial);
delay(1000);
Serial.println("\n--- Start---");
pinMode(ledPin, OUTPUT); // use the LED pin as an output
// begin initialization
if (!BLE.begin()) {
Serial.println("starting BLE failed!");
while (1);
}
Serial.print("My BLE MAC:\t\t ");
Serial.println(BLE.address());
Serial.print("Service UUID:\t\t ");
Serial.println(ledService.uuid());
Serial.print("Characteristic UUID:\t ");
Serial.println(switchCharacteristic.uuid());
Serial.println();
// set the local name peripheral advertises
BLE.setLocalName("LEDCallback");
// set the UUID for the service this peripheral advertises
BLE.setAdvertisedService(ledService);
// add the characteristic to the service
ledService.addCharacteristic(switchCharacteristic);
// add service
BLE.addService(ledService);
// assign event handlers for connected, disconnected to peripheral
BLE.setEventHandler(BLEConnected, blePeripheralConnectHandler);
BLE.setEventHandler(BLEDisconnected, blePeripheralDisconnectHandler);
// assign event handlers for characteristic
switchCharacteristic.setEventHandler(BLEWritten, switchCharacteristicWritten);
// set an initial value for the characteristic
switchCharacteristic.setValue(0);
// start advertising
BLE.advertise();
Serial.println(("Bluetooth device active, waiting for connections..."));
}
void loop() {
// poll for BLE events
BLE.poll();
}
void blePeripheralConnectHandler(BLEDevice central) {
// central connected event handler
Serial.print("Connected event, central: ");
Serial.println(central.address());
}
void blePeripheralDisconnectHandler(BLEDevice central) {
// central disconnected event handler
Serial.print("Disconnected event, central: ");
Serial.println(central.address());
}
void switchCharacteristicWritten(BLEDevice central, BLECharacteristic characteristic) {
// central wrote new value to characteristic, update LED
Serial.println("Characteristic event, written: ");
byte charValue = switchCharacteristic.value();
Serial.println(charValue);
if (charValue) {
Serial.println("LED on");
digitalWrite(ledPin, HIGH);
} else {
Serial.println("LED off");
digitalWrite(ledPin, LOW);
}
}
Raspberry Pi/Python BLE Central Side:
- bluepy library is used to control Bluetooth BLE.
To install bluepy for Python3, enter the command:
$ sudo pip3 install bluepy
- tkinter is
used for GUI.
py_BLE_Central_LedControl.py connect to Peripheral with matched
MAC, and search for service/characteristic with match UUID. Then send
0x01/0x00 to turn ON/OFF the Nano RP2040 Connect's onboard LED.
"""
Python/Raspberry Pi BluetoothLE exercise:
using bluepy library
Work with Arduino Nano RP2040 Connect example:
ArduinoBLE > Peripheral > CallbackLED
Connect to Peripheral with matched MAC.
Check for service uuid and characteristic uuid,
if matched found: send bytes 0x01 and 0x00 for three time
to turn Nano RP2040 Connect onboard LED ON/OFF.
"""
from bluepy import btle
import time
#Have to match with Peripheral
MAC = "84:cc:a8:2e:8d:76"
SERVICE_UUID = "19b10000-e8f2-537e-4f6c-d104768a1214"
CHARACTERISTIC_UUID = "19b10001-e8f2-537e-4f6c-d104768a1214"
nanoRP2040_Char = None
print("Hello")
print("Connect to:" + MAC)
dev = btle.Peripheral(MAC)
print("\n--- dev ----------------------------")
print(type(dev))
print(dev)
print("\n--- dev.services -------------------")
for svc in dev.services:
print(str(svc))
print("\n------------------------------------")
print("Get Serice By UUID: " + SERVICE_UUID)
service_uuid = btle.UUID(SERVICE_UUID)
service = dev.getServiceByUUID(service_uuid)
print(service)
print("\n--- service.getCharacteristics() ---")
print(type(service.getCharacteristics()))
print(service.getCharacteristics())
#----------------------------------------------
characteristics = dev.getCharacteristics()
print("\n--- dev.getCharacteristics() -------")
print(type(characteristics))
print(characteristics)
for char in characteristics:
print("----------")
print(type(char))
print(char)
print(char.uuid)
if(char.uuid == CHARACTERISTIC_UUID ):
print("=== !CHARACTERISTIC_UUID matched! ==")
nanoRP2040_Char = char
print(char)
print(dir(char))
#print(char.getDescriptors)
#print(char.propNames)
#print(char.properties)
#print(type(char.read()))
print(char.read())
bytes_ON = b'\x01'
bytes_OFF = b'\x00'
if nanoRP2040_Char != None:
print("\nnanoRP2040_Char found")
print(nanoRP2040_Char)
for i in range(3):
nanoRP2040_Char.write(bytes_ON, True)
print(nanoRP2040_Char.read())
time.sleep(1.0)
nanoRP2040_Char.write(bytes_OFF, True)
print(nanoRP2040_Char.read())
time.sleep(1.0)
else:
print("\nnanoRP2040_Char NOT found!")
#=============================================
dev.disconnect()
print("\n--- bye ---\n")
pyTk_BLE_Central_LedControl.py implement GUI with tkinter, user click on
button to turn ON/OFF LED.
"""
Python/Raspberry Pi BluetoothLE exercise:
using bluepy library
Work with Arduino Nano RP2040 Connect example:
ArduinoBLE > Peripheral > CallbackLED
Connect to Peripheral with matched MAC.
Check for service uuid and characteristic uuid,
if matched found:
Start GUI to control Nano RP2040 Connect onboard LED
"""
from bluepy import btle
import time
import tkinter as tk
#Have to match with Peripheral
MAC = "84:cc:a8:2e:8d:76"
SERVICE_UUID = "19b10000-e8f2-537e-4f6c-d104768a1214"
CHARACTERISTIC_UUID = "19b10001-e8f2-537e-4f6c-d104768a1214"
nanoRP2040_Char = None
def toggle():
if toggle_btn.config('relief')[-1] == 'sunken':
toggle_btn.config(relief="raised")
nanoRP2040_Char.write(bytes_OFF, True)
toggle_btn['text'] = 'Turn LED ON'
else:
toggle_btn.config(relief="sunken")
nanoRP2040_Char.write(bytes_ON, True)
toggle_btn['text'] = 'Turn LED OFF'
print("Hello")
print("Connect to:" + MAC)
dev = btle.Peripheral(MAC)
print("\n--- dev ----------------------------")
print(type(dev))
print(dev)
print("\n--- dev.services -------------------")
for svc in dev.services:
print(str(svc))
print("\n------------------------------------")
print("Get Serice By UUID: " + SERVICE_UUID)
service_uuid = btle.UUID(SERVICE_UUID)
service = dev.getServiceByUUID(service_uuid)
print(service)
print("\n--- service.getCharacteristics() ---")
print(type(service.getCharacteristics()))
print(service.getCharacteristics())
#----------------------------------------------
characteristics = dev.getCharacteristics()
print("\n--- dev.getCharacteristics() -------")
print(type(characteristics))
print(characteristics)
for char in characteristics:
print("----------")
print(type(char))
print(char)
print(char.uuid)
if(char.uuid == CHARACTERISTIC_UUID ):
print("=== !CHARACTERISTIC_UUID matched! ==")
nanoRP2040_Char = char
print(char)
print(dir(char))
#print(char.getDescriptors)
#print(char.propNames)
#print(char.properties)
#print(type(char.read()))
print(char.read())
bytes_ON = b'\x01'
bytes_OFF = b'\x00'
if nanoRP2040_Char != None:
print("\nnanoRP2040_Char found")
print(nanoRP2040_Char)
root = tk.Tk()
label = tk.Label( root, text="Toggle button to Turn ON/OFF the nano RP040 Connect LED")
label.pack(pady=10)
toggle_btn = tk.Button(text="Turn LED ON", width=12, relief="raised", command=toggle)
toggle_btn.pack(pady=10)
root.geometry("500x200")
#Place tkinter window center
root.eval('tk::PlaceWindow %s center' % root.winfo_pathname(root.winfo_id()))
root.title("arduino-er.blogspot.com")
root.mainloop()
else:
print("\nnanoRP2040_Char NOT found!")
#=============================================
dev.disconnect()
print("\n--- bye ---\n")
~
More exercises of Arduino Nano RP2040 Connect.
