The WiPhone project is about an ESP32-based mobile phone which is capable of making free calls over an IP network, instead of using the traditional public switched telephone network (PSTN). It can make phone calls over Wi-Fi, without the need for a cellular radio. The phone is intended to be hackable, modular, cheap and open-source, while remaining usable by everyday people.

According to the presentation of ESP32-WiPhone on hackaday.io, calling is completely free, as long as users can set up an account and install a SIP/VoIP application on the devices they need to call. This way there is no difference between international and local phone calls and, therefore, no restrictions on calling plans. Also, users do not need worry about radio compatibility or having to use another country’s SIM card when traveling.

The ESP32-WiPhone can also prove very useful to parents and children, since this particular phone eschews the distractions of a smartphone. Thus, it provides an ideal method of communication between them. What’s more, it can provide invaluable help to elderly or ill people and their carers. Users can give the person they look after a pre-configured phone that is set up with only the most necessary numbers. This way old people or those with frail health can be spared the trouble of memorizing and entering complex button combinations. 

A Rendering of the ESP32-WiPhone

Commercial phone interchange services are available, in case users need to call someone on a regular phone. Typical plans cost about $25 per year, an amount that is charged by US or Europe providers. Additionally, users can avoid being tracked by cell tower triangulation or IMSI catching (Stingray). They can also load their own firmware to implement different calling protocols or completely different use-cases. The firmware is unlocked and freely modifiable.

Populated Motherboard of ESP32-WiPhone

The ESP32-WiPhone supports wireless firmware updates. It is based on an ESP32 microprocessor and runs a type of software that is compatible with Arduino. The ESP32-WiPhone measures approximately 120mm x 65mm x 12mm and has a 2.4” LCD screen.