Addepalli Dolendra Vikas' DirectMessage Is a Cyberpunk Secure LoRa Communicator Handset

Designed for peer-to-peer secure chat, this handset is driven by an STM32 and includes a dedicated GNSS receiver for location sharing.

Gareth Halfacree
11 days ago β€’ Communication / HW101

Electronics hobbyist Addepalli Dolendra Vikas has put together a cyperpunk featurephone, of sorts, designed as a handheld secure communicator transmitting and receiving over a LoRa network: the directMessage.

"I planned to design and develop a device using the LoRa E5 SOC from the Seeed Studios, which can establish a secure communication channel where [a] 3rd person can't even predict the frequency of the channel you are using to communicate," Vikas writes of the project, brought to our attention by Seeed Studio. "This device is like a two-way pager with advanced features like live navigating and sharing location, altitude, and attitude. Still, it has a limited range of very few hundred meters."

The single-board handset is built around Seed's Wio-E5 module, which includes an STMicroelectronics STM32WLE5JC microcontroller and a Semtech SX126X LoRa radio module. Elsewhere on the board is a Quectel L80 global navigation satellite system (GNSS) receiver, driving the handset's location capabilities while a Bosch BME280 pressure sensor provides altitude data and an inertial measurement unit (IMU) offers additional direction and orientation data, a 1.8" ST7735 SPI display to drive the user interface with tactile switches beneath for inputs, and a small vibration motor to act in place of a ringer.

Not included in that list: a microphone or speaker. The directMessage isn't for voice chat, but for secure text messaging β€” using the peer-to-peer portion of the LoRa standard to connect to nearby handsets. Once connected, messages can be entered using the telephone-like keypad character by character β€” and location information quickly added into a message when required.

The design files and source code for the directMessage are available on Vikas' GitHub repository under the permissive MIT license.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.
Latest articles
Sponsored articles
Related articles
Latest articles
Read more
Related articles