Homer Simpson (with sound)

Introduction

In my spare time, next to 3D printing, I like to mess around with electronics, especially if I can combine it with 3D printing. I found a very compact MP3 module with an SD slot to put music or sound files on and thought this would make a very nice soundboard gadget. I combined it with an Wemos D1 controller based on the brilliant ESP8266 chip to control it and the idea was born. All I needed was a 3D design of Homer Simpson and a couple of MP3 soundbytes of the guy. The excellent design by RoberRollin (see link to original model) was a good source file to adapt.

After adapting the design to house the electronics, I printed it and painted the body. Pushed the electronics in the recesses and I had a talking Homer! I decided to give it two of my colleagues that were working in a remote location at the time, isolated from the rest of our research group. That way, they had a third companion to keep them company and they had a blast with him ever since.

I created firmware for the D1 controller that would connect to the local access point and offer a webform that enables you to set the volume of the sound and the time interval between quotes. Each time the interval elapsed, you'd hear a random Homer quote echoing through the office. At one time, my colleagues were remotely attending a group meeting and when the meeting organizer wrapped up the meeting, Homer cried out “BORING!!”. 

Electronics

The hardware components you need are:

• Wemos D1 ESP8266 controller (e.g. https://www.tinytronics.nl/shop/en/development-boards/microcontroller-boards/with-wi-fi/wemos-d1-mini-v4-esp8266-ch340, but I used the now discontinued https://www.tinytronics.nl/shop/en/wemos-d1-mini-v3-esp8266-ch340) 
• DFRobot DFPlayer (I used a clone https://www.tinytronics.nl/shop/en/audio/audio-sources/mini-mp3-module-yx5200, there are many more)
• 4 or 8 ohm speaker, I used a 40 mm one (there are two types available in the SCAD files)

In order to save space, I desoldered the pin header from the MP3 module. Then I connected the speaker to the MP3 module (pins SPK_1 and SPK_2). The Wemos D1 board is connected to the MP3 module with the pins:

• VCC on MP3 module to 3V3 of the Wemos board
• GND on MP3 to GND of the Wemos board
• RX on MP3 to D1 of the Wemos board
• TX on MP3 to D3 of the Wemos board

Make sure the wires between the two boards are short (~2 cm) and the wires to the speaker longer (~10 cm) for easy mounting. The Wemos board should be mounted in the recess with the USB connection positioned at the whole in the bottom of Homer. I used a little cyano-acrylate glue to fix it, so that the board would not shift around when you connect the USB cable. By the way, test the electronics and firmware before you mount it…

Firmware

I programmed the Wemos board with the Arduino IDE. There are two versions now, the old 1.8 and the new 2.0. I suggest to use the old one, since that version still supports a plugin that enables you to write data files to the SPIFFS system of the ESP8266. Version 2.0 does not have that yet.

Make sure your Arduino IDE is equipped with the drivers to program ESP boards (see Rui Santos' page https://randomnerdtutorials.com/how-to-install-esp8266-board-arduino-ide/ for more info on this). Then install the plugin to write data to SPIFFS (see https://randomnerdtutorials.com/install-esp32-filesystem-uploader-arduino-ide/). In addition, you probably have to install a few additional libraries (ESP8266LLMNR & Web Server, WiFiManager and DFMiniMP3).

You'll find the firmware, some sound files and the data files for the web interface in the enclosed file Homer_Simpson_MP3.zip. Unzip the folder, load Homer_Simpson_MP3.ino into the IDE, connect your Wemos board via USB and program it. Then you need to upload the data files for the web interface (in the data folder) with the Filesystem Uploader tool. Rui Santos' page on the uploader describes the process perfectly.

Oh, yes, before I forget, there is also another Arduino file, Homer_Simpson_MP3.ino_with_EEPROM, which provides the possibility to store your interval settings on the EEPROM. However, since it was some time ago since I created it, I cannot recall whether that really worked.

Source of the Homer image: https://wallpapers.com/wallpapers/homer-simpson-with-beer-kj3h1n6hzcpwg904.html by jefflarey. The tricky bit with the soundbyte MP3s is that I cannot really distribute them because of copyright. However, there are many sources available where you can download MP3 files for your own use. To name a few:

• https://www.thesoundarchive.com/simpsons.asp
• https://www.wavsource.com/tv/simpsons/homer1.htm
• https://www.101soundboards.com/boards/10393-homer-simpson-sounds-the-simpsons-seasons-1-and-2 

You need to put the quote MP3's on an SD card that goes into the MP3 module. Make sure you rename the files to the form XXXX.mp3 where the X's are consecutive 4 digit numbers, e.g. 0000.mp3, 0001.mp3, 0002.mp3, …, 0010.mp3, …

Connecting Homer

When you first connect Homer, you have to connect it to your wireless access point. Homer has a WiFiManager built in, so if it cannot connect to an access point that he is familiar with, he'll start an access point himself called Homer_Simpson. Connect your PC to this access point and a page will open where you can select your access point. You provide the password and from then on, Homer will know your access point and have access to it automatically. He then restarts and when you reconnect your PC to your regular access point, you can connect to Homer with a browser. Type the URL homer.local in your address bar and Homer's setting page will open. This does not work on many mobile platforms, because those usually cannot handle LLMNR. In that case, you need to find the IP address of your Homer and use that to navigate to. Little annoying, but hey, what can you do.

Description files

I've used MeshMixer to reduce the number of polygons a little to make the files more easily adaptable (*.mix files). Then I used OpenScad to create the necessary recesses to house the electronics and the speaker (*.scad) and of course also included the STL files here.