• Analog TV may have shuffled off its mortal coil years ago, but there are still plenty of old CRT TV sets around that could receive it. • [Kris Slyka] has just such a device, and decided tofeed it something from an STM32 microcontroller. • An STM32G431, to be precise, and he’s doing it using the on-chip hardware rather than in software. • This unexpected feat is made possible by clever use of the internal oscillators and analog multiplexer. • The video itself is generated using the MCU’s DAC, and fed into the on-board op-amp multiplexer which is switched at the VHF transmission frequency. • This creates the required VHF TV transmission, but without audio.

Article Summaries:

  • A hobbyist has used an STM32G431 microcontroller to generate a VHF analog TV signal without software. By exploiting the MCU’s internal oscillators and analog multiplexer, the DAC produces a video waveform that is fed into an on‑board op‑amp multiplexer switched at the VHF transmission frequency. A frequency‑modulated USB RC oscillator provides the carrier offset, creating a black‑and‑white composite signal that can drive a CRT. The design omits audio and the PAL colour sub‑carrier, but demonstrates an unconventional use of MCU peripherals for analog TV transmission. The article also references earlier ESP8266‑based TV transmitters and suggests future NTSC implementations.

Sources: