Leave a digital message behind for your loved one on the Arduino based Love Memo! Simply place the little memo box anywhere in your house for your beloved to see. For example; on his or her nightstand, office room, hobby space, or wherever there is access to your Wifi. Once installed and connected, you’ll be able to send messages to it by using any device that is also connected to the same WiFi as your mobile phone, tablet or pc. When the message is sent, the little heart on the box will light up and your BF/GF can tap on the heart to reveal the message ‘inside’! This way, you’ll avoid yelling at each other when you are out of hearing range!
But first, you will need to make and connect everything! Let’s get crackin’!
- PLA natural for the transparent heart
- any PLA color for the rest of the case, we used the NEW PLA Satin Blue Filament
- NodeMcu V2 Lua based ESP8266 Development Board
- the following items that you will need can be found in the Basic Learning Kit for Raspberry Pi (VMP502):
- shift register
- 50K potentiometer
- 1602 LCD module
- 2 x red LEDs
- soft electrical wires
- eurocard (B/ECI)
- USB A to mini B
- 12 x small screws (2 / 2.5mm x 9mm – we used regular servo screws)
Tools and accessories:
- stripping pliers
- soldering iron
- shrink tubes
- a heat gun or hair dryer
- philips screwdriver
2. 3D Printing the case and button
Find all the .stl files for the case and button of this project on our Thingiverse page: https://www.thingiverse.com/thing:4157141
Be sure to 3D print the button in a transparent filament. Otherwise, you won’t be able to see the flashing LED underneath. Also, be sure to print it with 100% infill to get the best result.
The case can be 3D printed as-is, without any support. But if you are having trouble with warping, you can always add a brim just to be sure.
3. Preparing the Arduino IDE for the NodeMcu V2 Lua Based ESP8266 development board
Before we can start programming, first you have to do a few steps to install the NodeMcu ESP8266 software. Follow the steps under downloads / User manual. /product/nodemcu-v2-lua-based-esp8266-development-board-vma107/
4. Programming the NodeMcu V2 Lua Based ESP8266 Development Board
Step 1: Download the code here: https://github.com/Velleman/Tutorials/tree/master/Love_Memo
Step 2: Open the code and search for the WiFi settings and change it to yours.
Step 3: Open the serial monitor and upload the code. Make sure that your baud rate is set to 115200 in de serial monitor.
Step 4: Once the code is uploaded and the ESP8266 is connected with your WiFi, the serial monitor will show your IP address.
Step 5: When the Love Memo is completely finished, you will need to enter this IP address in a browser on your phone, tablet, laptop (make sure you are on the same network). Then it will show a type box where you can enter your message. You can already test this right now.
5. Prepping the connection
Check out the electrical connection scheme below and use it while following the steps below. Do not solder/connect it yet! To clarify, we will explain every step below.
6. Soldering the Electronics and Assembly
Step 1: Start by cutting a heart shape and rectangle out of a Eurocard.
Rectangle dimensions: 56 x 25 mm
Heart shape: wait until the case is 3D printed and make sure the heart-shaped Eurocard can fit in the heart-shaped button.
Step 3: Solder the shift register onto the Eurocard.
Step 4: Make the connections form the ESP8266 to the shift register according to the connection scheme. (make sure to test fit everything to know the cable lengths)
Step 5: Make the connections form the shift register to the LCD according to the connection scheme.
Step 6: Screw the potentiometer in place. (you may have to make the hole slightly bigger) and connect the wires to it.
Step 7: Solder the wires that go to the button and the 2 LEDs on the ESP8266. Place the ESP8266 in the case and lead the wires through the hole in the casing that leads to the heart. You can screw the ESP8266 and LCD screen to the provided places.
Step 8: Then solder the button in the middle of the heart-shaped Eurocard (test fit it with the printed button). After that, solder the 2 LEDs.
Step 9: Then connect the wires to the button and 2 LEDs according to the connection scheme.
It should look something like this:
Step10: Use 4 screws to attach the LCD screen to the top plate. Now you can close the casing and screw it together.
Step 11: Click the printed heart button in place.
DONE! Now make your love happy by sending him/her a sweet memo.