MicroPython ESP8266 Nokia 5110 Bitcoin Price Index

A MicroPython library for displaying bitcoin price index on a Nokia 5110 display with PCD8544 driver.

Powered by CoinDesk and their free Bitcoin Price Index API.

Prices are converted to Australian dollars (AUD) using hourly conversion rate from openexchangerates.org. You can change this to another currency by changing the api endpoint.

Prices are updated around every 84 seconds.

The 84x48 PCD8544 buffer:

Initial setup

1. Copy the files to your ESP8266 board

   • using WebREPL
     • See ESP8266 QuickRef
   • using ampy
     • see Adafruit ampy guide
   • compiling into the firmware
     • make erase
     • copy bitcoin_ticker.py to /esp8266/modules
     • copy bitcoin_ticker_test.py to /esp8266/modules
     • copy pcd8544.py to /esp8266/modules
     • make deploy

2. Connect to WiFi, credentials are persisted, so you wont need to enter them each time

   >>> import network
   >>> sta_if = network.WLAN(network.STA_IF);
   >>> sta_if.active(True)
   >>> sta_if.scan()
   >>> sta_if.connect("ssid","pass")
   >>> sta_if.isconnected()

   Disable the AP, unless you need it.

   >>> ap_if = network.WLAN(network.AP_IF)
   >>> ap_if.active(False)

3. Install urequests with upip. You need to be on WiFi for this to work.

   >>> import upip
   >>> upip.install('micropython-urequests')

   Did it install?

   >>> import os
   >>> os.listdir()
   ['boot.py', 'lib']
   >>> os.listdir('lib')
   ['urequests.py']

   Yes!

4. Run the demo

   import bitcoin_ticker_test

Example Coindesk API json response:

{
	"time":{
		"updated":"May 23, 2017 07:14:00 UTC",
		"updatedISO":"2017-05-23T07:14:00+00:00",
		"updateduk":"May 23, 2017 at 08:14 BST"
	},
	"disclaimer":"This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org",
	"bpi":{
		"USD":{
			"code":"USD",
			"rate":"2,214.9088",
			"description":"United States Dollar",
			"rate_float":2214.9088
		},
		"AUD":{
			"code":"AUD",
			"rate":"2,955.7979",
			"description":"Australian Dollar",
			"rate_float":2955.7979
		}
	}
}

bpi.AUD.rate_float is parsed from the json and displayed on the LCD.

Parts

• WeMos D1 Mini $4.00 USD
• Nokia 5110 module $1.77 USD
• Breadboard 400 point $0.90 USD
• Jumper wire $1.09 USD

Connections

WeMos D1 Mini	Nokia 5110 PCD8544 LCD
D3 (GPIO0)	0 RST
D4 (GPIO2)	1 CE
D8 (GPIO15)	2 DC
D7 (GPIO13)	3 Din
D5 (GPIO14)	4 Clk
3V3	5 Vcc
D6 (GPIO12)	6 BL
G	7 Gnd

Links

• MicroPython PCD8544 Driver
• WeMos D1 Mini
• micropython.org

Credits

• Bitcoin Logo Wikipedia (Creative Commons CC0 1.0)

License

Licensed under the MIT License.