├── README.md
└── main.py


/README.md:
--------------------------------------------------------------------------------
 1 | ESP8266 IOT Button
 2 | ==================
 3 | 
 4 | ![Photo](http://i.imgur.com/osWEN4Z.jpg)
 5 | 
 6 | This code is intended to be used with an ESP8266 flashed with MicroPython.
 7 | See [here](http://imgur.com/a/e4KuA) for an album and more info on hardware.
 8 | 
 9 | ![Schematic](http://i.imgur.com/mnZ3CU8.png)
10 | 
11 | I used [esptool](https://github.com/espressif/esptool) to flash the MCU, and
12 | [ampy](https://github.com/adafruit/ampy) to perform the initial upload of
13 | `main.py`. After that, all other code uploads can be done using
14 | [webrepl](https://github.com/micropython/webrepl)
15 | 
16 | To program, hold down S2 (the program button) while pressing S1 (the main
17 | button). This will put turn the device into an access point you can connect to.
18 | Look for an ssid that starts with "IOTBTN-". Then, use webrepl to connect to
19 | the device (just open webrepl.html in your browser, it's all client-side code).
20 | 
21 | Use webrepl to upload a config.json file like so:
22 | 
23 | ```json
24 | {
25 |   "ssid": "your-wifi-ssid",
26 |   "password": "your-wifi-password",
27 |   "broker": "mqtt-broker-ip",
28 |   "topic": "example/topic/name"
29 | }
30 | ```
31 | 
32 | Next time you press the button, the device will power up, publish the topic to
33 | the broker, and will then go into deep-sleep mode. The first press will connect
34 | using DHCP, and then save a static wifi config (this makes future connections a
35 | bit faster). So, the first press will take longer than subsequent presses.
36 | 


--------------------------------------------------------------------------------
/main.py:
--------------------------------------------------------------------------------
  1 | import utime as time
  2 | import ujson as json
  3 | import ubinascii as binascii
  4 | import network
  5 | import machine
  6 | from machine import Pin
  7 | from umqtt.simple import MQTTClient
  8 | 
  9 | script_start = time.ticks_ms()
 10 | CLIENT_ID = binascii.hexlify(machine.unique_id()).decode('utf-8')
 11 | 
 12 | # load config
 13 | with open('config.json', 'r') as config_file:
 14 |     config = json.load(config_file)
 15 | 
 16 | # set up pins
 17 | led = Pin(2, Pin.OUT, value=0)
 18 | 
 19 | # To enable config mode (webrepl), connect GPIO0 to GND via 10K resistor
 20 | config_mode_enabled = Pin(0, Pin.IN).value() == 0
 21 | 
 22 | 
 23 | def run():
 24 |     print('starting up...')
 25 | 
 26 |     # turn led on
 27 |     led.low()
 28 | 
 29 |     if config_mode_enabled:
 30 |         run_config_mode()
 31 |     else:
 32 |         run_action()
 33 | 
 34 |     # turn led off
 35 |     led.high()
 36 | 
 37 | 
 38 | def finish():
 39 |     print("total runtime: {}ms".format(time.ticks_ms() - script_start))
 40 | 
 41 |     if not config_mode_enabled:
 42 |         print("sleeping...")
 43 |         machine.deepsleep()
 44 | 
 45 | 
 46 | def connect_wifi():
 47 |     wlan = network.WLAN(network.STA_IF)
 48 |     wlan.active(True)
 49 |     static = None
 50 | 
 51 |     try:
 52 |         with open('static.cfg', 'r') as static_cfg:
 53 |             print('found static config')
 54 |             static = static_cfg.read().strip().split('\n')
 55 |             if len(static) < 4:
 56 |                 static = None
 57 |     except OSError:
 58 |         pass
 59 | 
 60 |     if static:
 61 |         print('using static config: ', static)
 62 |         wlan.ifconfig(static)
 63 | 
 64 |     if not wlan.isconnected():
 65 |         print('connecting to network...')
 66 |         wlan.connect(config['ssid'], config['password'])
 67 |         while not wlan.isconnected():
 68 |             pass
 69 | 
 70 |     if static is None:
 71 |         # save wifi config for faster reconnection
 72 |         ifconfig = '\n'.join(wlan.ifconfig())
 73 |         with open('static.cfg', 'w') as static_cfg:
 74 |             print('Saving static config')
 75 |             static_cfg.write(ifconfig)
 76 | 
 77 | 
 78 | def run_config_mode():
 79 |     import webrepl
 80 |     ap = network.WLAN(network.AP_IF)
 81 |     ap_essid = config.get('ap_essid', 'IOTBTN-{}'.format(CLIENT_ID))
 82 |     ap_password = config.get('ap_password', 'iotbutton')
 83 |     ap.config(essid=ap_essid, password=ap_password)
 84 |     webrepl.start()
 85 |     print('ESSID: {}\nPASS: {}'.format(ap_essid, ap_password))
 86 | 
 87 | 
 88 | def run_action():
 89 |     connect_wifi()
 90 |     print('connecting to broker: {}'.format(config['broker']))
 91 |     broker = config['broker']
 92 |     topic = config.get('topic', 'button/{}'.format(CLIENT_ID.lower()))
 93 |     client = MQTTClient(CLIENT_ID, broker)
 94 |     client.connect()
 95 |     print('publishing topic: {} "pressed"'.format(topic))
 96 |     client.publish(topic, 'pressed')
 97 |     client.disconnect()
 98 | 
 99 | 
100 | try:
101 |     run()
102 | finally:
103 |     finish()
104 | 


--------------------------------------------------------------------------------