This is a small LiPo battery powered display console.
- 4.2 inch 400x300 E-Ink E-Paper Display Modul
- ESP32 Lolin32 board
- 4 capacitive touch buttons
- LiPo 3,7V 1000mAh
LiPo batteries cause a fire risk. You should test the proper charge and discharge behavior of the used board. Purchase high quality products. Don't use damaged or puffy LiPo batteries. Check regularly. Never leave the device charging while unattended. Remove the LiPo battery if the device is not used and store it safe. Respect correct disposal of the battery.
I am using this device to control some home automation features. It's controlled via the 4 touch buttons, which are used as soft keys. The ESP32 is normally in deep sleep mode and wakes up every minute to update the time, or if any buttons is touched. The communication is based on Bluetooth LE to a central, which provides the characteristics for the current time and status information to be displayed. Further BLE characteristics are available to control the home automation functions.
I have chosen BLE in order to consume less power. A 1000mAh battery should last 5 days.
Optionally a wireless QI receiver module can be used for convenient charging of the LiPo battery.
- LOLIN32 V1.0.0-ESP32.
- Qi wirles charging receiver module (optional)
- Waveshare 4.2 inch 400x300 E-Ink E-Paper Display Modul - B/W version to allow fast partial update.
- LiPo with 2-pin JST-PH connector.
- 4 thumbtacks
- Dupont jumper wire - Optionally if you don't want to solder the buttons directly.
- Screws and Nuts.
With the Qi charging module PETG or ABS shall be used to avoid deformation of the box.
Shorten the thumbtack pins with a side cutter so that the remaining pin sticks out about 0.5 mm. Solder the wires with the dupont jumper to the backside of the thumbtacks. The dupont jumper fits to the hole in the lid. Finally glue the thumbtacks together with the lid.
You may use parts of my project and adapt to your needs. I am using the display console to show status information from my home automation server. A Raspberry Pi Zero W, which is installed in the living room works as MQTT to BLE gateway. This is a NodeJS service unsing bleno.
The ESP32 in the display wakes up every minute to update the time. The accuracy of the low frequency clock of the ESP32 is not high. Hence it is required to synchronisiere the clock after every now and then. A BLE connection is established according to the commIntervalls definition in configuration.h. The connection is also established if one of the 4 buttons is touched. After the connection to the service is available, the device receives time and status Information and sends commands if requested.