macmacmac
Feb 28, 2016 - 19:47
The Pythonista code below connects to an HM-10 BLE module connected to an Arduino (TX>RX, RX>TX). It sends the character 'H' to turn on the internal LED of the Arduino.
It works, but is it possible to simplify the code? I know the name of the module (HM-10-BLE) the UUID of its only service (FFE0) and the UUID of its only characteristic (FFE1). Do I really have to scan and compare, discover and compare and discover and compare each and every time I want to connect? Is there a way to connect directly using name and UUIDs?
# Sending the character 'H' to an HM-10 BLE module
# Module Name 'HM-10-BLE’
# Module Service UUID 'FFE1'
# Module Characteristics UUID 'FFE0'
import cb
class MyCentralManagerDelegate (object):
def __init__(self):
self.peripheral = None
def did_discover_peripheral(self, p):
if p.name == 'HM-10-BLE' and not self.peripheral:
print 'Discovered ' + p.name
self.peripheral = p
cb.connect_peripheral(self.peripheral)
def did_connect_peripheral(self, p):
print 'Connected Peripheral ' + p.name
print 'Looking for Service FFE0'
p.discover_services()
def did_discover_services(self, p, error):
for s in p.services:
if s.uuid == 'FFE0':
print 'Found Service ' + s.uuid
print 'Looking for Characteristic FFE1'
p.discover_characteristics(s)
def did_discover_characteristics(self, s, error):
for c in s.characteristics:
if c.uuid == 'FFE1':
print 'Found Characteristic ' + c.uuid
print 'Writing H'
self.peripheral.write_characteristic_value(c, 'H', False)
cb.set_central_delegate( MyCentralManagerDelegate() )
print 'Looking for HM-10-BLE module'
cb.scan_for_peripherals()
# Keep the connection alive until the 'Stop' button is pressed:
try:
while True: pass
except KeyboardInterrupt:
# Disconnect everything:
cb.reset()
.
.
Arduino code:
/*
Turns thes LED on pin 13 on or off
Serial.read(); reads one byte in ASCII Format.
The result is either 65 or ‘A’ in single quotess
*/
#include <SoftwareSerial.h>
SoftwareSerial softSerial(10, 11); // RX, TX
byte command;
void setup() {
softSerial.begin(9600);
pinMode(13, OUTPUT);
}
void loop() {
command = softSerial.read(); //Read one byte
if (command == 'L') {
digitalWrite(13, LOW);
command=0;
}
if (command == 'H') {
digitalWrite(13, HIGH);
command=0;
}
}