Introduction: Electromyography Spacecraft
Hello everybody and welcome to our project!
First of all, we would like to introduce ourselves. We are a group of three students of ‘Creative Electronics’, a BEng Electronic Engineering 4th year module at the University of Malaga, School of Telecommunication (https://www.uma.es/etsi-de-telecomunicacion/).
The aim of this project is to demystify and demonstrate friendly uses of medical instruments, such as electrodes, by developing a videogame using these electrodes as sensors. The electrodes read the electrical activity of muscles, that is called electromyography (EMG). We treat that signal and use it to control the movement of the spaceship in our videogame. The electrodes are connected to both forearms, and we are able to register 3 types of movements. Holding tight something soft with our left or right hand will produce a movement of the spaceship to the left or right. The third type of movement is registered by holding tight both hands at the same time, and it will shoot the laser beam of our spaceship. Down below we will show you how to do that movement with your hands in video.
Let's get started!
Step 1: Buying the Essentials
Here is the list of the required components to make this project:
- Arduino SAV-Maker, we reproduced this development board for this subject, so we decided to use it! Here is the link to the github: https://github.com/fmalpartida/SAV-MAKER-I
- 2 x OLIMEX Arduino Shield for EMG/EKG.
- Bluetooth Module HC-05.
- A powerbank that fits in the wooden box and a USB cable to power up the Arduino.
- 1 meter of wire with at least 3 threads inside.
- 6x banana male connectors.
- 2x 3.5mm jack male connectors.
- 6x TENS electrodes.
- A wooden box.
- 4x bolts and nuts.
- 2x iron plates, to keep all the components in the box tight.
Step 2: Solder the Wire to the Jack and Banana Connectors
The OLIMEX shields have a female 3.5mm jack connector, therefore, it is required a wire with a male 3.5mm jack connector on one side of the wire, and 3 male banana connectors on the other side. These banana connectors will be connected to the electrodes. Each thread of the wire will be soldered as you can see in the diagram above. The white banana is the "ground electrode" or reference electrode, which will be sticked on our elbow. The two other banana connectors are the electrodes that read the electric activity of the forearm muscle. You need two wires in order to connect the shields to each forearm.
Step 3: Connect Everything
As you can see in the image, the connections are very simple, thanks to the shields, which are placed on top of the Arduino. We also have to connect the bluetooth module, using the pins shown in the diagram. Connect the wires to the shields and the electrodes, and we are done with the hardware!
Step 4: Coding
Here is the link to the github repository containing the videogame, coded in Processing, and the Arduino code.
The fully functional videogame is in the folder named Processing/EMG_Demo_Game
Step 5: Final Assembly
Prepare the wooden box to introduce all the components, making a few holes for the bolts and wires. Try your plates and bolts, and if the components are loose, add a little piece of polystyrene like we did, to make sure that all the components are tight. This step is completely up to you, if you have a 3D printer available, you can print your own box!
Step 6: Play!
At first, you will need a few minutes to adapt, because the movement is a bit tricky, but once you get used to it, you will control it nicely. The video attached shows an early version of the videogame, because there are no objectives to shoot, you have to download the github version to try the final game!
Thanks for visiting our project and have fun making it!