This project started with a simple idea, let's make a phone from an old radio. The radio, which from the design started, is from one of my old friend, who found it at a garbage disposal.

I will be thankful for any suggestions on how to improve the design.

• LILYGO TTGO T-CALL ESP32 SIM800L
• 1602 LCD Display
• I2C LCD Driver
• BME280 Temperature and humidity sensor
• Rotary encoder
• Push button
• 2 x Rocker switch
• Slide switch
• 4 x White led
• 4 x 470 ohm resistor
• 2 x 220 kohm resistor
• Microphone
• 8 ohm speaker
• Li-ion battery charger
• DC-DC Boost converter
• 5V Voltage regulator LM1084IT-5.0
• 3 x 18650 battery
• 3 x 18650 battery case
• 2 x Custom PCB, designs included here (you can order them here)

• Programming
  • Arduino IDE
  • USB-C cable
• Mounting material
  • Wire
  • Solder wire
  • Insulating tape
  • Heatshrink
• Tools
  • Soldering iron
  • Wire cutter

1. Main page (shows date, time, battery charge, temperature, signal strength)
2. Contact list (saved contacts readed from flash memory of ESP32)
3. Messages (you get a message, if you have a missed call)
4. Restart (reboot the phone)
5. Dial number (you can dial a number if you want to call without saving it)
6. Save contact (save a phone number with a contact name)
7. Delete contact (no need to explain)
8. Change in call volume
9. Change ringer volume

You can select the above menu items by pressing the sidebutton, the rotary encoder is used for scrolling between them. If the sidebutton is pressed, while on the main page, the backlight will turn OFF/ON. If the backlight is off, any input will be ignored except for one, the sidebutton is used to turn the backlight on again.

Main board
Power management extension (will be updated)

Early render

Rendering took around 13 hours.