This should be roughly what was done here, but written in ruby.
first, in your polybar folder
$ git clone https://github.com/itsmaia/polybar-crypto && cd polybar-crypto
$ mkdir ~/.config/polybar/crypto && cp ./{crypto-config.rb,main.rb} ~/.config/polybar/crypto
Then, put your API key (CoinMarketCap) and desired coins at crypto-config.rb
.
@coins = { :bitcoin => "bitcoin_icon", :dash => "dash_icon" }
@currency = 'USD'
@api_key = 'YOUR KEY HERE'
In your polybar config file:
...
modules-right = crypto memory cpu temperature date
...
[module/crypto]
type = custom/script
interval = 600
exec = ruby ~/.config/polybar/crypto/main.rb
@willHol used the cryptocoins font in his project and i think its pretty neat, you can take a look at that if you want to.
This is licensed under do whatever you want with it.