What about using Raspberry Pi Pico instead of Arduino in BITX?

| September 4, 2026 | Amateur Radio (Ham Radio) | No Comments

Last few days we were having discussions on 40m and 2m on the Raduino replacement board being developed by VU3EBS for Easy BITX. He has successfully incorporated CQ function and a colour TFT for his modified version of Easy BITX. Thought of searching whether there is already a similar option out there. VU3EBS had already mentioned that the pin configuration of the dual band Easy BITX which I had homebrewed is not compatible with his PCB. I was quite surprised to find that AJ6CU has already attempted it for uBITX! His Github page mentions both Raspberry Pi Pico and Zero. There are a few great pictures as well.

1. The Hardware (PCB and Gerbers)

AJ6CU has published the PCB designs in his GitHub repository called 32bit-Raduino-Board_Designs. The specific Gerber files for the Raspberry Pi Pico version are located in a folder named RaduinoClone/RaspberryPiPico within his repository.

  • The board is designed as a drop-in physical replacement for the standard Raduino header.
  • It handles the 3.3V logic translation and provides the surface-mount pads for the Si5351 clock generator.

2. The Firmware

To accompany the hardware, AJ6CU successfully ported the highly popular KD8CEC Raduino firmware to run on the Raspberry Pi Pico.

  • Because the Pico handles analog and digital pins differently than the Arduino Nano, the firmware and board design remap the rotary encoder, the encoder button, and the PTT lines away from the analog pins over to standard GPIO pins (specifically GPIO 17, 18, 19, and 22).

The Easy BITX Audio Amplifier Catch

AJ6CU designed his Pico Raduino board primarily for the uBITX transceiver. In the uBITX architecture, the LM386 audio amplifier was moved to the main transceiver board. However, in the standard Easy BITX (and the BITX40), the audio amplifier is located directly on the Raduino board itself.

Because AJ6CU design assumes the audio amp is elsewhere, his Pico board does not include an LM386 circuit. To make this work for your Easy BITX, two options can be tried:

  1. Modify the Gerbers: Open AJ6CU files in a PCB editor and add an LM386, a few capacitors, and a volume pot header to the empty space on the board before having it manufactured.
  2. Use an off-the-shelf module: Build AJ6CU board as-is, and wire a standard LM386 module between the Easy BITX product detector output and the speaker.

I am just sharing the information that I got online. Not sure whether it will work and how difficult it is to implement. Meanwhile I am waiting for VU3EBS to complete his project and release it online so that it will avoid a lot of designing and teething trouble. Incidentally, during our morning 40m discussions today, VU2BR suggested the name PicoBITX for the VU3EBS version! As of now that name has not been taken and it is for VU3EBS to use it or not.