ardeshirv / btc-ticker-esp8266

realtime bitcoin price on 7 segment display with arduino on esp8266

Bitcoin price ticker with ESP8266 (realtime websockets)

• 7-segment 8-bit - or - Dot Matrix LED Display support with 32x8px
• bitstamp & bitfinex websocket interfacing for lightning fast, real time updates!
• solderless build possible (if you order the display with pre-soldered pin headers)
• low power (<0.5W), cheap to build (around 5 EUR)

pictures in action

v0.2-bitstamp-websockets in action (gfycat link)

3D printed coinboard case

v0.3 with dot matrix display

original prototype

components

• ESP8266 Wemos D1 R2 Uno (link) or ESP8266s/NodeMCUs (link) or Wemos D1 Mini
• 7 segment display with MAX7219 (link) or Dot Matrix display (link)
• dupont cables (female-to-male) and maybe a cheap antenna ;)

wiring 7-segment (software SPI, Wemos D1 Mini)

D1 Mini	Display
GND	GND
5V/VIN	VCC
D8	CS
D7	DIN
D5	CLK

wiring dot-matrix-display using hardware SPI

NodeMCU	Display
GND	GND
5V/VIN	VCC
D2	CS
D5	CLK
D7	DIN

how to install

• flash the board
  • upload source sketch with arduino IDE
  • or flash binary (download) with esptool (python) or flash download tools (WIN) @ address 0x0
• connect board to power
• connect your smartphone/computer to ESPxxxxxx wifi
• enter your home wifi settings at the captive portal

3D printed case options

these are the 3rd party designs I have tested for this project

Case	Link	Remarks
coinboard	https://www.thingiverse.com/thing:2785082	Wemos D1 only, works okish with some hotglue (picture)
ESP8266 Matrix Display Case	https://www.thingiverse.com/thing:2885225	printed too small, pay attention to your matrix module size! mine was a little larger
IR Remote Tester	https://www.thingiverse.com/thing:1413083	works good (I closed the sensor hole above the display) but screw mechanism needs rework or maybe screw inserts

known issues

• compilation error in LedControl.h:
  solution: comment out or delete pgmspace.h include

TODO

• ! correct level-shifting to 5V (3.3V is out of spec, but works anyway)
• add 5th digit for next ATHs ;-)
• web portal configuration
• better error handling (although it seems to be pretty stable with good connection)
• maybe use websockets for real-time ticker
• add more APIs and currencies plus option to choose
• TLS support for HTTPS requests
• options for 3D printed case