Closed
Description
I documented how I tested BLE Uart here. An incorrect Service UUID is returned if the sketch is modified to add a servo. The modified sketch is shown below. Also, a Python script is provided to act as a BLE central and to print out what is being returned from the Arduino R4.
I don't know if this is related to issue #309.
The expected UUID should be UART_SERVICE_UUID = "6E400001-B5A3-F393-E0A9-E50E24DCCA9E"
#include <HardwareBLESerial.h>
// Uncomment these next two lines to demonstrate bug
#include <Servo.h>
Servo myServo ;
HardwareBLESerial &bleSerial = HardwareBLESerial::getInstance();
void setup() {
Serial.begin(115200);
while (!Serial);
if (!bleSerial.beginAndSetupBLE("SerialPassthrough")) {
while (true) {
Serial.println("failed to initialize HardwareBLESerial!");
delay(1000);
}
}
// wait for a central device to connect
while (!bleSerial);
Serial.println("HardwareBLESerial central device connected!");
}
void loop() {
// this must be called regularly to perform BLE updates
bleSerial.poll();
// whatever is written to BLE UART appears in the Serial Monitor
while (bleSerial.available() > 0) {
Serial.write(bleSerial.read());
}
// whatever is written in Serial Monitor appears in BLE UART
while (Serial.available() > 0) {
bleSerial.write(Serial.read());
}
}
"""
Copyright (c) 2020-2023 Alan Yorinks All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
Version 3 as published by the Free Software Foundation; either
or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU AFFERO GENERAL PUBLIC LICENSE
along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""
import asyncio
import sys
import bleak
from bleak import BleakClient, BleakScanner
from bleak.backends.characteristic import BleakGATTCharacteristic
from bleak.backends.device import BLEDevice
from bleak.backends.scanner import AdvertisementData
UART_SERVICE_UUID = "6E400001-B5A3-F393-E0A9-E50E24DCCA9E"
UART_RX_CHAR_UUID = "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
UART_TX_CHAR_UUID = "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"
class TelemetrixAioBle:
"""
This class encapsulates management of a BLE UART connection that communicates
with an Arduino UNO R4 WIFI
"""
def __init__(self, ble_device_name="SerialPassthrough"):
self.ble_device_name = ble_device_name
self.ble_device = None
self.bleak_client = None
async def connect(self):
"""
This method connects to a device matching the ble_device_name
:return:
"""
print(f'Scanning for BLE device {self.ble_device_name}. Please wait...')
self.ble_device = await BleakScanner.find_device_by_name(self.ble_device_name)
if self.ble_device is None:
raise RuntimeError('Did not find the BLE device. Please check name.')
print(f'Found {self.ble_device_name} address: {self.ble_device.address}')
self.bleak_client = BleakClient(self.ble_device.address)
await self.bleak_client.connect()
print('Connected')
print(self.ble_device.details)
sys.exit(0)
theBle = TelemetrixAioBle()
asyncio.run(theBle.connect())
Here is the output of the Python script with the servo added. The item to look at is UUIDs. It is clearly not the UART_SERVICE_UUID.
Scanning for BLE device SerialPassthrough. Please wait...
Found SerialPassthrough address: DC:54:75:C3:BD:CD
Connected
{'path': '/org/bluez/hci0/dev_DC_54_75_C3_BD_CD', 'props': {'Address': 'DC:54:75:C3:BD:CD', 'AddressType': 'public', 'Name': 'SerialPassthrough', 'Alias': 'SerialPassthrough', 'Paired': False, 'Bonded': False, 'Trusted': False, 'Blocked': False, 'LegacyPairing': False, 'Connected': False, 'UUIDs': ['00001800-0000-1000-8000-00805f9b34fb', '00001801-0000-1000-8000-00805f9b34fb'], 'Adapter': '/org/bluez/hci0', 'ServicesResolved': False, 'RSSI': -70}}
If I comment out the lines adding the servo, here is the output of the Python script:
Scanning for BLE device SerialPassthrough. Please wait...
Found SerialPassthrough address: DC:54:75:C3:BD:CD
Connected
{'path': '/org/bluez/hci0/dev_DC_54_75_C3_BD_CD', 'props': {'Address': 'DC:54:75:C3:BD:CD', 'AddressType': 'public', 'Name': 'SerialPassthrough', 'Alias': 'SerialPassthrough', 'Paired': False, 'Bonded': False, 'Trusted': False, 'Blocked': False, 'LegacyPairing': False, 'RSSI': -73, 'Connected': False, 'UUIDs': ['6e400001-b5a3-f393-e0a9-e50e24dcca9e'], 'Adapter': '/org/bluez/hci0', 'ServicesResolved': False}}
Here the UUID is correct.
Discussion topic:
https://forum.arduino.cc/t/ble-returns-incorrect-uuid-if-a-servo-is-instantiated/1150072