rgco has crafted an impressive arbitrary waveform generator using the Raspberry Pi Pico, showcasing the capabilities of modern microcontrollers in waveform generation. Unlike the past, where specialized equipment or extensive analog electronics were necessary, this project leverages the fast microcontroller’s capabilities for waveform generation. The build represents an enhancement of rgco’s earlier work with the Arduino Uno, achieving a remarkable 125 megasamples per second, a significant improvement over the previous 381 kilosamples per second.
The Raspberry Pi Pico’s faster clock speed, coupled with performance optimizations and the utilization of DMA and PIO subsystems, enables the generation of a new sample every clock cycle. This results in a cost-effective function generator that can be assembled with a Raspberry Pi Pico and a few resistors. Notably, the device surpasses the speed of counterparts based on the AD9833 function generator chip, which runs at 25 megasamples per second and is limited to generating sine, triangle, and square waves.