TWANG32 – An ESP32 Port of TWANG
I ported the TWANG game over to ESP32. I wanted to do this for several reasons.
- Cost: The ESP32 is generally lower cost than the Arduino Mega
- Speed: The ESP32 has a dual core 80MHz processor vs. the 16MHz Arduino Mega
- Memory: The ESP32 has much more RAM and program space to allow more features, levels and audio files.
- Physical Size: A Mega is very big. This creates a large enclosure that takes a while to print. The smaller enclosure is also more portable.
- DAC Pins: The audio capabilities on the Mega are very crude and basically limited to square wave tones. A DAC can output digital audio. Currently I am just using a similar square wave tone to the Mega, but it works much better for adjusting the volume.
- Wireless: The ESP32 has Wifi and Bluetooth. This will allow easier (smartphone) interfacing for options (brightness, volume) and level pack uploads. I also want to consider dual player battle type games with linked controllers.
The Audio
The original TWANG bit banged audio directly from I/O to a speaker. This was super simple, but the volume at max was not loud enough for noisy environments. The ESP32 I/O is a lower voltage (3.3v) and less current, so something needed to be done. I prototyped with a PAM8403 based amplifier (~$4 on Amazon). This worked great, so I added that I.C. to my shield. The volume is controlled by the amplitude of the DAC.
The Shield
I made a shield to simply the wiring and provide a stable way to mount the ESP32. I used a NodeMCU 32S development board for the ESP32. Under the ESP32 is a the audio circuitry. I should have some extra boards to sell on Tindie soon. I will publish the source files soon.
The Firmware
The code is on Github. The port was relatively easy, but I had to rewrite a few libraries. They were designed so the main “setup” and “loop” parts did not change much. Currently the serial port based setup from the Mega version was not ported. This probably won’t be used. A wireless version is in the works.
Enclosure
The new enclosure is smaller. It prints quicker and is easier to fit in my backpack. The size is still big enough to hold comfortably while playing. The files will be uploaded to Thingiverse within the week.
Next Steps
- Wireless control: I want a simple way to read the game statistics (average score, levels played, boos kills, etc) and tweak simple settings like audio volume and brightness. I think the easiest way is to make it a wifi access point with a simple web server. This eliminates having to write any client side apps and any smartphone or computer can hope on easily.
- Levels: Make some way to edit or upload levels via wifi.
- Multiplayer: I should be able to link multiple controllers. If I can think of a good dual player game idea, I might try to add that.
- Python: It might be a fun challenge to write the game in Micro Python. This might open up the development to more people.
If you want to be notified of future blog posts, please subscribe.
Bart
What do you think of using two ESP32s and ESPNow to connect them wirelessly? Then you physically separate the controller from light strip. Right now I’m a little concerned about an excited player yanking the light strip around.
Easy for me to suggest when you’re doing all the work!
Thanks,
Queeg
That is an interesting idea if I start seeing that problem.
I have thought, if you did something like that you could use a smartphone as the accelerometer and speaker. That would pull a lot of cost out. It is not a good solution if you want to walk away from it in a public place.