I used your code to extend it so the oled could display your current hashrate from nanopool and added some features like offline detection. You can access it on github. https://github.com/o0pwnd0o/miningmonitor

Am enjoying having a play with this but can not seem to figure out how to get to show after the decimal for sub dollar coins. Sorry if this is a stupid question but its my first time using away from the arduino ide. Thanks

It's not you, the code isn't very well commented. This line:

btcrate = string.format("%d", t[1]["price_eur"]+0.5);

pulls the rate from the json array and displays it as whole numbers.

To make it show decimals, you want something like:

btcrate = string.format("%.3f", t[1]["price_eur"]);

3f will display 3 numbers after the decimal point.

thanks for that working like a charm now. I was playing with the %.3 wouldn’t of tried f. Keep up the good work. 

It looks very nice!

I added logo's for eth, zec and bch and changed Monero to Ethereum

<code>

ethlogo = string.char(0x80, 0x00, 0xc0, 0x01, 0xe0, 0x03, 0xe0, 0x03, 0xf0, 0x07, 0xf0, 0x07, 0xf8, 0x0f, 0xfc, 0x1f, 0xf0, 0x07, 0xec, 0x1b, 0x98, 0x0c, 0x70, 0x07, 0xf0, 0x07, 0xe0, 0x03, 0xc0, 0x01, 0x80, 0x00);
zeclogo = string.char(0xe0, 0x07, 0xf8, 0x1f, 0x1c, 0x38, 0x8e, 0x71, 0xe6, 0x67, 0xe3, 0xc7, 0x03, 0xc7, 0x83, 0xc3, 0xc3, 0xc1, 0xc3, 0xc0, 0xe3, 0xc7, 0xe6, 0x67, 0x8e, 0x71, 0x1c, 0x38, 0xf8, 0x1f, 0xe0, 0x07);
bchlogo = string.char(0xb6, 0x7f, 0x6e, 0x7f, 0x0e, 0x78, 0x06, 0x70, 0xc2, 0x71, 0xc6, 0x73, 0x8e, 0x61, 0x0e, 0x40, 0x0e, 0x47, 0x9e, 0x4f, 0x1e, 0x47, 0x1e, 0x61, 0x1e, 0x70, 0x0e, 0x78, 0x7e, 0x7b, 0xfe, 0x76);

</code>

Did you already take steps to alternate between two or more pages?

I would like to show two combinations, one page with BTC/ETH and a page with BCH/ZEC.

Thanks for eth symbol. Can you create USD symbol too?

Here you go. I just made this the other day. :)

usdsym = string.char(0x80, 0x01, 0x80, 0x01, 0xe0, 0x0f, 0xf0, 0x0f, 0x70, 0x00, 0x70, 0x00, 0xf0, 0x01, 0xe0, 0x07, 0xc0, 0x0f, 0x00, 0x0f, 0x00, 0x0e, 0x00, 0x0e, 0xf0, 0x0f, 0xf0, 0x07, 0x80, 0x01, 0x80, 0x01);

I also made a cleaner BTC logo as well as a ZEC logo:

btclogo = string.char(0x60, 0x01, 0x60, 0x01, 0xfc, 0x0f, 0xfc, 0x0f, 0x70, 0x1c, 0x70, 0x1c, 0x70, 0x1c, 0xf0, 0x0f, 0xf0, 0x1f, 0x70, 0x3c, 0x70, 0x38, 0x70, 0x3c, 0xfc, 0x1f, 0xfc, 0x0f, 0x60, 0x01, 0x60, 0x01);

zeclogo = string.char(0x80, 0x01, 0x80, 0x01, 0xf0, 0x1f, 0xf0, 0x1f, 0xf0, 0x1f, 0x00, 0x0f, 0x80, 0x07, 0xc0, 0x03, 0xc0, 0x01, 0xe0, 0x01, 0xf0, 0x00, 0xf8, 0x0f, 0xf8, 0x0f, 0xf8, 0x0f, 0x80, 0x01, 0x80, 0x01);

I use the ZEC logo for ZCL, but it could also be used for any of the other Z coins. 

To displays 2 pages alternately you could create 2 getrates files then set the timer to increment a counter and display one on even numbers, the other on odd.

Im having trouble with memory issues.

In my serial console i get:

E:M 5128
HTTP request failed

The unit then crashes and reboots. Ive deleted the update_display.lua  to troubleshoot and commented out the call to run the update_display.lua file. Still has the same issues. Any thoughts?

I'm not sure, I've not seen this type of error before, how much heap space do you have free? What module type/firmware version/etc? If could be worth trying with just one currency, you could change the last line of getrates.lua to call getxmrrate instead of getbtcrate, see if that works?

Can you share your 3D print case ? :-)

It's linked above, on the left.

https://www.thingiverse.com/thing:857858

It's not the most convenient case, not a lot of room to fix the screen or wire it up, but it looks quite good.

I think those OLED displays have too slow refresh rate for the recent changes in bitcoin prices ;-)

I think the bigger problem was space on the screen for 6 digits, I eliminated the mantissa so we should be good until it hits a million ;-)