This standalone camera passes the image with SSTV


These days, sending a photo to someone else is as easy as pulling out your smartphone and sending it via email or text. It’s so simple that a child can do it, but this simple user experience masks huge complexity, from the compression algorithms in phones to the huge amount of distributed infrastructure needed to connect them together. As wonderful and empowering as all this infrastructure can be, sometimes it’s too much for the job.

This seems to have been the case for [Dzl TheEvilGenius], which just wanted to send a low resolution image from a remote location. Turns out hams solved that problem about 70 years ago with slow scan television, or SSTV. As most of the world settled in front of “I Love Lucy” on the regular hit, ham radio operators sought to use their equipment to send pictures around the world. But where the hams of old had to throw a considerable amount of equipment at the problem, [Dzl] just used an ESP-32 with a camera and custom code to process the image. The output from one of the MCU’s GPIO pins is a PWM audio signal that can be fed directly into the microphone input of a cheap portable transceiver.

To decode the signal, [Dzl] used one of the many SSTV programs available. There’s no mention of the receiver, although it could be pretty much anything from another Baofeng to an SDR dongle. The code is available in the article, as is an audio file of an encoded image, if you just want to play with the receive and decode side of the equation.

We could see something like this working for a remote security camera, or even scouting hunting spots. If you want to reproduce this, remember that you will need a license if you want to transmit on the amateur radio bands – relax, it’s easy.


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