As a child a long time in the past, for those who needed to speak over the air with your pals within the neighborhood, you may use a walkie-talkie to squawk out messages to one another. For a number of causes, this not often labored properly, however as we speak there’s a brand new wi-fi know-how on the block: the LoRa long-range, low-bandwidth wi-fi protocol. It is nice for textual content messages, however not a lot for voice communication.
Prolific hacker David Johnson-Davies (DJD) constructed a easy textual content communicator primarily based on the LoRa protocol known as the Walkie-Textie – versus a voice-based walkie-talkie. The hand-held system is good in its simplicity. The physique is a pair of screwed-together PCBs, and it incorporates a 128×64 pixel monochrome I2C OLED show as its foremost visible interface. It additionally has an LED and a piezo beeper to point when a message is obtained. Enter is by way of a 12-button interface for multi-tap texting, much like how cellphone textual content enter (slightly annoyingly) labored a decade or two in the past.
LoRa communication is dealt with by a HopeRF RFM95W module, whereas all the things is managed by an ATtiny814. The system is supposed for use with a LiPo battery, although different energy sources may be carried out with the correct JST plug, plus a easy firmware modification to regulate the Walkie-Textie’s battery sensing routine.
Much more particulars may be discovered on DJD’s Technoblogy submit, together with code and board information. Notably, messages can, in principle, be learn by anybody in receiving vary, so that you’ll wish to maintain delicate data – like the situation of your secret hideout – off the air, or implement an encryption routine. The Walkie-Textie appears to be like like numerous enjoyable to construct and use, and it’s neat to see one other system implementing LoRa know-how!
