ElektroThing's DS-Pi Is a Feature-Packed Digital Signal Processor Built Around a Raspberry Pi RP2040
Designed to drive a guitar effects pedal, this clever board is programmable in the Arduino IDE, via MicroPython, or CircuitPython.
Pseudonymous electronics engineer elektroThing has put together a digital signal processing platform with a difference: the DS-Pi is driven by a Raspberry Pi RP2040 microcontroller, alongside a Texas Instruments audio codec and an on-board amplifier.
"The DS-Pi is an open source RP2040-based audio digital signal processing platform that can be used to perform filtering and other DSP processes on audio inputs and outputs," elektroThing explains of the project. "The DS-Pi leverages the low-cost and highly accessible platform that is the RP2040 with a powerful audio codec from Texas Instruments, the TLV320AIC3254."
As well as the microcontroller and audio codec, the DS-Pi includes a Maxim MAX97220BETE+T headphone amplifier, an on-board MEMS microphone amplifier, 4MB of flash memory, and a 3.5mm audio jack alongside screw terminals for external microphone inputs and audio outputs.
Impressively, the board also includes a pair of general-purpose input/output (GPIO) headers — offering, elektroThing claims, the same connectivity as the Raspberry Pi Pico development board in the same layout, albeit spaced more widely apart. On the software side, the board supports programming from the Arduino IDE or in MicroPython or CircuitPython.
"Standing on the shoulders of giants, one of the aims of this project is to make the platform fully compatible with the work that Blackaddr has worked on for [a guitar effects pedal based on] the Teensy platform," elektroThing explains. "While there might be some limitations with hardware, the dual-core [Arm Cortex-M0+s] on the RP2040 should be able to cope with some interesting processing.
"Driven by a personal interest/need, this platform could [also] be used for bedroom guitarist who wants to jam into the wee hours of the evening with their headphones and hopefully an amp model that they can customize."
More details are available on the project's Hackster page, with work-in-progress source code and schematics published to GitHub under the permissive MIT license.