In this video tutorial, I'll explain how you can build your own "Smart Dice" - wireless cubes that use the MPU6050 linear accelerometer on a GY-521 board to detect which way up they are, and broadcast that information via an MQTT message to a Node-RED broker.
You can use these to build an escape room puzzle where players need to arrange a set of dice to make a certain total of the face-up sides, or rotate them in a particular way to follow a numeric sequence, for example.
I'm using a Wemos D1 Mini, ESP8266-based board which is ideal for portable escape room props, because:
- it's physically small
- it has a convenient battery shield to provide portable power from a single Li-Po cell
- it has built in Wi-Fi
- it runs at 3.3V logic, which means that there is no logic-level conversion required on the I2C wires between the processor and the (3.3V) sensor
However, you can also follow exactly the same steps described here to connect the MPU-6050 sensor an ESP32 board, or an Arduino UNO or Nano (even though that won't have Wi-Fi unless you add a suitable Wi-Fi shield). To demonstrate how you can create code that is portable between several different target devices, I'm also not going to use any third-party libraries designed for the MPU-6050 chip - instead I'll teach you how you can write and read values directly to any I2C component using the built-in, generic "Wire" library. This is useful information to know should you ever find yourself wanting to use an I²C component in a project and these is not an existing library available!
Components
---
GY-521 board (MPU-6050 chip), https://www.banggood.com/custlink/v33hSP1shT
Wemos D1 Mini (ESP8266 chip), https://www.banggood.com/custlink/v33RJLItSj
D1 Mini Battery Shield, https://www.banggood.com/custlink/mvGhSFfsh2
Total cost = ~$7
Timings
---
00:00:00-00:03:23 Introduction and Demonstration
00:03:23-00:07:17 Hardware Overview
00:07:18-00:19:02 Wiring and power requirements
00:19:03-01:00:07 Arduino/ESP8266/ESP32 Code
01:00:08-01:15:36 Node-RED flow
01:15:37-01:17:28 Wrapup
Code & Wiring Downloads
---
If you'd like to support me making more video tutorials explaining how to use tech in escape rooms and other playful settings, please check out my Patreon at https://www.patreon.com/playfultech, where you can also find code downloads, wiring diagrams, and additional resources for this and all my other tech projects.