:::-: b:t-t:cka :-:::

bitcoin ticker/block clock with a raspi + 20x4 alphanumeric lcd

This simple Bitcoin ticker/ block clock connects to a BitcoinExplorer instance and displays some stats about the bitcoin network such as exchange rates, halving countdown, latest block, etc..

It can also connect to a Mempool instance, or even your own BTC Core node, but at time of writing there are limited views available for these options.

Required Components

• Raspberry pi + raspi OS installed (I used an old 3b I had kicking around but most pi's should work so long as they have internet capabilities. ie.pi3/4/5,zero w, etc.)
• 20x4 alphanumeric LCD with PCF8574 I2C expander (or you could do it without the expander but instructions for the extra wiring are not included here)
• 4 jumper cables to go from pi to the display
• A BitcoinExplorer instance to connect to (self hosted and connected to your own BTC Core node is recommended)

Connect the display

Connecting a pi to a PCF8574 expander is simple and there are many tutorials online if the following basic outline is insufficient (eg. here or here )

There are only 4 pins on the LCD expander, each one needs to be connected to the pi in the following manor:

• SDA -> SDA
• SCL -> SCL
• GND -> GND
• VCC -> 5v

Enable I2C

1. open raspi-config:

sudo raspi-config

2. Select Interface Options from the list
3. Make sure I2c is enabled

Install i2c-tools and get LCD address

1. install tools:

sudo apt-get install i2c-tools

2. reboot pi
3. find the address:

i2cdetect -y 1

You should now see a table similar to below in which one cell contains a number. Note this number down.

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- 27 -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --  

Install other dependencies

sudo pip install RPLCD

sudo apt install python-smbus

Optional depedencies for BTC RPC

If you wish to connect to your Bitcoin Core node then you'll need the following packages

pip install bitcoinrpc typing-extensions httpx orjson asyncio

Clone this repo

git clone https://github.com/BrightonBTC/bitticka.git
cd bitticka

Configure

Copy config.example.py to config.py and open it for editing

sudo cp config.example.py config.py
sudo nano config.py

Change the LCD_ADDRESS to the one you noted down earlier, and change API/RPC details to your self hosted or preferred instances. At time of writing most of the views available use the bitcoinexplorer API, but a couple of screens are also available via the mempool API and Bitcoin Core.

LCD_ADDRESS = 0x27

# URL of a bitcoin explorer instance. No trailing slash.
EXPLORER_API_URL = 'https://bitcoinexplorer.org'

# mempool API URL if required
# MEMPOOL_API_URL = 'https://mempool.space'

# Bitcoin Core details if required
BITCOIN_RPC_AUTH = {
    'user': "",
    'password': "",
    'url': "http://192.168.1.99:8332"  
}

Test run

Whilst still in the bitticka dir run the script to make sure it's working.

python3 ./btcticker.py

You should now see the welcome screen appear

Run as a service

If you want to run it as a service so that it will always run after a reboot etc., then:

sudo nano /etc/systemd/system/btcticker.service

Enter the following making sure to make the appropriate change to the .../bitticka/btcticker.py path and user name

[Unit]
Description=BTC Ticker/BlockClock
After=multi-user.target
[Service]
Type=simple
Restart=always
ExecStart=/usr/bin/python3 /home/[user]/bitticka/btcticker.py
User=[user]
[Install]
WantedBy=multi-user.target

And run the service:

sudo systemctl daemon-reload
sudo systemctl enable btcticker.service
sudo systemctl restart btcticker.service

## check everythings working
sudo systemctl status btcticker.service
sudo journalctl -f -u btcticker.service

Further Configuration

See the config.py file for a few other params that can be adjusted.

The various screens that are displayed on the LCD are grouped in to sections, you can adjust the order and selection of sections be changing the order in btcticker.py

# btcticker.py

## load the views depending on which API's you're using
import views.fun as fun
import views.explorer as explorer
import views.mempool as mempool
import views.btccore as btccore

## views called here run once on start up
fun.welcome()

while 1:
    ## views inside the while loop will loop indefinitely
    fun.lfg()

    mempool.DifficultySection()

    explorer.McapSection()
    explorer.HalvingSection()
    explorer.XRatesSection()
    explorer.SatRatesSection()
    explorer.BlockheightSection()
    explorer.SupplySection()

    btccore.SmartFeesSection()

any views before the while loop play once when bitticka first loads. Anything inside the while loop will loop continuously.

If you're comfortable writing a bit of Python code it would be fairly trivial to add extra views. You can refer to views.py. If you use the write_big() function in your view just be aware that it only handles a limited set of chars (0-9 and lowercase alphanumeric are safe) and any additional ones would need to be mapped and added to the big_chars array in chars.py.

If you create anything cool that other might want to use then consider putting in a pull request.