Open Source Firmware for the DeepSDR 101
Thank you to Esteban Benito (EA8DGL) for writing in and sharing news of a bare-metal open source firmware for the GD32F450-based DeepSDR 101. The firmware is a collaborative effort developed by Esteban Benito (EA8DGL), Alexandr (UA6YKK), and Blas (EA7GIB). The DeepSDR 101 is a popular low-cost hand-held SDR, covering 100 kHz to 149 MHz, with a bandwidth of 192 kHZ, and a 4.3-inch screen. Various clones of the DeepSDR 101 also appear on marketplaces.
Esteban notes that the motivation for writing custom firmware was that the DeepSDR 101 and its clones have had only one firmware update since it came out. While the stock firmware currently works well, it lacks certain features such as selectable filter bandwidths and some demodulation modes, and it needs an updated interface.
Esteban writes:
The idea was to take genuinely inexpensive hardware - a GD32F450 microcontroller, an 800x480 touchscreen, a TLV320AIC3204 audio codec used as the I/Q front-end, and an MS5351 (Si5351-compatible) local oscillator - and turn it into a receiver with features you'd normally only find on much pricier radios:
- A real-time spectrum/waterfall panadapter with adjustable zoom (1x-8x), smoothing, and trace styles
- AM, USB, LSB, NFM and WFM demodulation, with adjustable channel bandwidth and squelch
- One-tap band presets (shortwave, airband, 2m, HF ham bands, FM broadcast, CB, and more), each pre-loaded with the right mode and tuning step
- A touchscreen settings menu with configurable AGC profiles, PGA gain, backlight, and more
- Encoder-based tuning down to 100Hz steps across 4.8-180MHzEverything is bare-metal C - no RTOS, direct register access for clocks/DMA/I2S - and the whole firmware, from the I2S/audio bring-up to the DSP chain to the UI,
With this being fully open, it also opens the door to things like CW, RTTY, SSTV, HF FAX or FT8 decoding down the line - none of that requires new hardware, just firmware that's actually open enough to build on.
So really, the goal isn't to replace or criticize the original firmware - it's to give the community a base to build on, so one of the most affordable and easy-to-use SDR radios out there can keep getting better over time instead of staying frozen after a single update.
AI-Disclaimer: We point out that Esteban discloses that this firmware is primarily being written with AI.
