electronic tennis scoreboard with mqtt interface

hardware

• an existing analog scoreboard like in the picture
• 6 WeAct Studio Epaper Module 2,9 '' https://github.com/WeActStudio/WeActStudio.EpaperModule
• esp32 nodencu board https://www.berrybase.de/esp32-nodemcu-development-board
• arcade buttons

wiring

Epaper modules

Each Epaper module has got 8 wires. According to GxEPD2 library 6 of them can be shared. Only the CS,Busy wires have be treated individually.

EPaper wire	GPIO pin
VCC	3.3 V
GND	GND
SDA	23
SCL	18
CS	individual
D/C	17
Reset	16
Busy	individual

The individual GPIO pins can be read from the arduino code.

buttons

button	GPIO pin
set games for home in set	34
set games for guest in set	35
change set	32
reset board	33

caveat: as the GPIO pins 34,35 don't have an internal pullup resistor, you need to connect manually a pullup resistor (10k ohm) to 3.3V.

howto use

manual use

After powering up the board sets every score to 0 (like in reset) in a FullWindow mode -> GxEPD2 library. The Epaper module is blinking. By default the focus is set to set1. You can use the 2 buttons to set the games in the set by counting up the games. To change the focus of the set you use the change set button. The number of games for home in the following set is being re-displayed in FullWindow mode, so it is blinking. This indicates that the set has been changed successfully. The reset button resets the board like in powering up.

use with mqtt

The boards connects to mqtt broker to a main topic

• it subscribes to the /toCourt1
• it publishes to the /fromCourt1

The data format is json, examples (mosquitto client):

• toCourt1:

mosquitto_pub -t Tennisscoreboard/toCourt1 -m "{ Score: { \"HeimSet1\": "5", \"GastSet1\": "4", \"HeimSet2\": "0", \"GastSet2\": "0", \"HeimSet3\": "0", \"GastSet3\": "0" }}"
mosquitto_pub -t Tennisscoreboard/toCourt1 -m "{ reset: \"true\" }"

• fromCourt1:

mosquitto_sub -t Tennisscoreboard/fromCourt1 
{"HeimSet1":6,"GastSet1":4,"HeimSet2":0,"GastSet2":0,"HeimSet3":0,"GastSet3":0}