Affenkopp

This project is about reading button states with a nodemcu and use the values in unity3d for fun and fame and the whole family. Push the buttons to control mapped eyes of an ape.

Hardware Setup

• 3x 3,7V 18650 (from old notebook batteries)
  • in series (11,1V max. 12,8V)
  • battery case
• 1x nodemcu (8€)
  • remember to disconnect the batteries before you hook up USB cable!!!
• 2x arcade buttons with LEDs (3€ each)
• 2x 1kOhm resistor

Optional For Battery Monitoring

• 330kOhm + 22kOhm resistor (voltage divider)
• 1x mini LED Voltmeter 3-30V (3€)

wifi access point

• its ssid & password must be hard coded in .ino file
• also acts as mqttbroker

Small Computer Which Runs Unity3d

Projector Mapping An Ape Shape

Buttons

• easy as: https://www.arduino.cc/en/tutorial/button
• button 1 & 2 at nodemcu D1 & D2
• LED inside button are wired straight to batteries (7-12V)

Protection, Voltage Regulator

• https://www.rugged-circuits.com/10-ways-to-destroy-an-arduino/
• http://www.esp8266.com/viewtopic.php?f=13&t=8889
• https://tinker.yeoman.com.au/2016/05/29/running-nodemcu-on-a-battery-esp8266-low-power-consumption-revisited/

Sleep Mode

330-1kOhm resistor between GPIO16 and RESET

• https://blog.falafel.com/esp8266nodemcu-deep-sleep/

Connection

Two ways to transmit the buttonstateinfo...

Wifi Client

nodemcu connects as client to wifi access point

• no long wires needed for buttons
• needs power supply
• needs separate wifi ap

USB

• no extra power supply needed for nodemcu

Software

How does the information of a pressed button reach the unity pc?

use "Serial.print(...)" on nodemcu via USB to computer

• http://answers.unity3d.com/questions/179311/unity-to-arduino.html
• https://www.youtube.com/watch?v=9SYt4MDSAro

Nodemcu As Simple HTTP Server

• fetching data in unity via http
• send requests from pc multiple times a second
  • works with upto 30 requests per second
  • time for i in {1..1000}; do curl -s --url http://172.16.0.135/buttons; done
• https://docs.unity3d.com/Manual/UnityWebRequest-RetrievingTextBinaryData.html
• https://github.com/andyburke/UnityHTTP

Nodemcu As HTTP Client, Webserver On PC/Unity?

• request a url if button is pressed
• https://www.myelectronicslab.com/tutorial/door-sensor-with-push-notification-using-esp8266-nodemcu/

MQTT Messages Via Broker

• the IoT way of sending messages, fast and without overhead
• needs a broker like "mosquitto"
  • available for linux, windows and openwrt
• mqtt clients
  • arduino
    • https://pubsubclient.knolleary.net/ -- pubsubclient
    • https://github.com/gonzalo123/mqtt_example
    • mqttclient
  • python
    • paho-mqtt
    • https://github.com/sumnerboy12/mqtt-gpio-monitor/blob/master/mqtt-gpio-monitor.py
  • micropython
    • umqtt.simple micropython client
    • https://github.com/gonzalo123/mqtt_example
  • unity
    • https://github.com/vovacooper/Unity3d_MQTT
    • https://m2mqtt4unity.codeplex.com
    • http://www.hivemq.com/blog/mqtt-client-library-encyclopedia-m2mqtt

MQTT Broker On Debian Stretch

aptitude install mosquitto
cp path_to_this_git/mosquitto.conf /etc/mosquitto/conf.d/
mosquitto_sub -d -h localhost -t "buttons" -t "node"

MQTT Broker On Openwrt

opkg update; opkg install mosquitto-nossl
vi /etc/mosquitto/mosquitto.conf

• https://github.com/remakeelectric/owrt_pub_feeds

Websockets

• http://www.instructables.com/id/Esp8266Websockets-RGB-LED-controller/
• https://github.com/ghtomcat/ArduinoWebsocketServer
• https://forum.unity3d.com/threads/unity5-beta-webgl-unity-websockets-plug-in.277567/
• https://github.com/sta/websocket-sharp

Unity on Linux

https://forum.unity3d.com/threads/unity-on-linux-release-notes-and-known-issues.350256/

Power Consumption @ 3.3V

• NodeMCU in wifi station mode 90mA
• NodeMCU with wifi suspended 40mA
• 7-segment voltmeter 12mA
• LED in button 35mA (12V)

li-ion accu

• high voltage 4.2V
• low voltage 2.75V