There seemed to be a lack of simple working crypto tickers, some of them due to the linked API being shut down and others due to issues with code or the dependant libraries.

Most of the tickers here on Instructables are USD and Bitcoin oriented, however I was looking for a XRP ticker that would display in ZAR.

Most of the tickers I tried failed with a 301 error(site perm redirected), when I tried to substitute the API url in their code.

Turns out it is because I was trying to access a HTTPS page using a HTTP coded ESP NodeMCU.

The way to circumvent certificate fingerprint checking is to use the "client->setInsecure();" command.

What I have done is remixed the code at Buger's Blog specifically his "how to get bitcoin exchange rate from blockchain.info API" example at the bottom of the page, with the SSD1306 display and JSON code from a user on Youtube, TheResidentSkeptic, who was kind enough to link his pastebin repo.

I couldnt get kevlar429's ticker code to compile, but I did mange to copy the https://min-api.cryptocompare.com/ url that he was using and change the coin/currency/exhcange to my liking.

XenonJohn's Rekt-O-Matic Turbo S provided the idea for the enclosure which I crafted in Tinkercad.

Supplies

Bare minimum:

ESP8266 NodeMCU 12E.

OLED 0.96" display.

Optional for battery driven:

DC-DC CONVERTER BOOST I=0.9-5V O=5V 0.6A, this will be used to drive the ESP8266 and display.

Single cell TP4056 style lipo charger, MICRO USB LITHIUM 18650 BATTERY CHARGER 1A.

18650 lipo cell, or cellphone battery etc.

Step 1: Hardware and Wiring.

I used the default SDA = D2, SCL = D1 for hooking up the display's I2C pins.

I also took off the red on led on the DC DC boost pcb, I didnt need it to show me the Nodemcu was on and I figured it would save some power.

Header pins of the nodemcu were cut to save space and the batt power wires were soldered onto the topside Vin, GND contacts.

Flexing battery holders with integrated spring https://www.thingiverse.com/thing:456900

The Efest 2500mah 18650 lasts about 3 days before needing a charge, ticker gets switched off at night.

Step 2: Software

Compiled using Arduino IDE 1.8.13.

ArduinoJson by Benoît Blanchon version 6.16.1

ArduinoJson Assistant V6 was used to deserialize after copying the info from the browser.

Ive taken the liberty of including the full code of both TheResidentSkeptic and Buger's Blog in a text file just in case their sites disappear.

The url that I edited "https://min-api.cryptocompare.com/data/pricemulti?fsyms=XRP&tsyms=ZAR&e=Luno&extraParams=your_app_name" with my changes in bold text.

A look on the Cryptocompare site will provide the supported exchanges, coins and currency.

Needless to say, I have very limited coding skills, being more of a copy/paste user, so my code may be somewhat dirty. :)