DIY open-source ultrasound hardware on the rp2040/rp2350

# pic0rick Source: [http://un0rick.cc/pic0rick](http://un0rick.cc/pic0rick)  [](https://join.slack.com/t/usdevkit/shared_invite/zt-2g501obl-z53YHyGOOMZjeCXuXzjZow)[](https://www.patreon.com/kelu124)[](https://ko-fi.com/G2G81MT0G) ## [http://un0rick.cc/pic0rick#the-pic0rick](http://un0rick.cc/pic0rick#the-pic0rick)The pic0rick The pic0rick is the current recommended board in the un0rick family\. It replaces the FPGA\-based designs with an RP2040/RP2350 microcontroller, delivering comparable ultrasound acquisition performance at a fraction of the cost and complexity — with no FPGA toolchains or specialized hardware knowledge required\. **New to the project?**Start with the[Getting started guide](http://un0rick.cc/getting-started)for a step\-by\-step walkthrough from unboxing to your first echo\.  --- ## [http://un0rick.cc/pic0rick#specifications](http://un0rick.cc/pic0rick#specifications)Specifications ParameterValue**Microcontroller**RP2040 \(dual\-core Cortex\-M0\+, 133 MHz\)\. RP2350 also supported**ADC**60 Msps, 10\-bit resolution**TGC amplifier**AD8331 — 7\.5 dB to 55\.5 dB variable gain**TGC control**MCP4812 SPI DAC**Pulse generation**Three\-level pulser via MD1210 \+ TC6320 \(on pulser PMOD board\)**Pulse voltage**\+\-25 V \(via HV generation board\)**Input protection**HV clipping on receive path**PMOD connectors**1x single \(pulser\), 1x double \(VGA, MUX, PSRAM, or custom\)**Data interface**USB \(serial\)**PIO usage**PIO0: acquisition timing, PIO1: VGA output \(when connected\)**Power**USB bus powered**Design files**KiCad \(open source\)**Firmware**C/C\+\+ for RP2040 — Arduino\-like development environment**Certification**[OSHWA open\-source hardware certified as FR000023](https://certification.oshwa.org/fr000023.html) --- ## [http://un0rick.cc/pic0rick#system-architecture](http://un0rick.cc/pic0rick#system-architecture)System architecture The pic0rick is a modular three\-board system: **Main board**— The core of the system\. Contains the RP2040 microcontroller, the 60 Msps 10\-bit ADC, the AD8331 TGC amplifier with SPI\-controlled gain curve, and HV input protection on the receive path\. The main board hosts both PMOD connectors and the USB interface\. **Pulser board**\(single PMOD\) — Generates the transmit pulse on behalf of the main board\. Uses a pair of MD1210 \+ TC6320 to produce three\-level pulses\. Requires the HV board for high\-voltage supply\. **HV board**— A simple \+\-25V generation board that plugs into the pulser board\. Provides the high\-voltage rail needed for pulse generation\. The signal chain works as follows: ``` RP2040 → PIO triggers pulse → Pulser board → Transducer → Echo returns → HV clipping (protection) → AD8331 TGC → 60 Msps ADC → RP2040 → USB → Computer ``` The RP2040’s two PIO units are used for precise timing: one drives the acquisition sequence \(pulse trigger \+ ADC sampling\), and the other can drive a VGA output for real\-time visualization — leaving the two Cortex\-M0\+ cores free for your own application code\. --- ## [http://un0rick.cc/pic0rick#how-does-it-replace-the-fpga](http://un0rick.cc/pic0rick#how-does-it-replace-the-fpga)How does it replace the FPGA? Previous boards \(un0rick, lit3rick\) used a Lattice iCE40 FPGA for precise timing control of the pulse\-echo sequence\. The pic0rick achieves the same timing precision using the RP2040’s Programmable Input/Output \(PIO\) state machines\. PIO programs run deterministically at the system clock rate, providing the sub\-microsecond timing needed for ultrasound acquisition — without requiring HDL knowledge or FPGA synthesis tools\. This means you can modify the acquisition timing, pulse patterns, and sampling parameters by editing C code in a standard Arduino\-like environment, rather than writing Verilog or VHDL and running a synthesis toolchain\. --- ## [http://un0rick.cc/pic0rick#pmod-extensions](http://un0rick.cc/pic0rick#pmod-extensions)PMOD extensions The double PMOD connector supports several expansion boards: ExtensionFunction**VGA output**Real\-time display of acquisitions on a VGA monitor — uses PIO1**MUX board**Multiplexer for driving multiple transducers — enables array imaging and synthetic aperture**PSRAM**Additional memory for longer acquisition buffers**Custom**The PMOD pinout is documented — design your own extensions Note: the PMOD headers include a 5V rail in addition to the standard signals, so they are not strictly PMOD\-compliant — but this allows powering more demanding extension boards directly\. For more details, see the[Extensions page](http://un0rick.cc/pmods)\. --- ## [http://un0rick.cc/pic0rick#board-comparison](http://un0rick.cc/pic0rick#board-comparison)Board comparison How does the pic0rick compare to the older un0rick\-family boards? **pic0rick**[un0rick](https://un0rick.cc/un0rick)[lit3rick](https://un0rick.cc/lit3rick)[lit3\-32](https://un0rick.cc/lit3-32)**Status****Active**LegacyLegacyLegacy**Years**2024–now2018–20252020–20242021–2024**Controller**RP2040 / RP2350iCE40 HX4K/HX8KiCE40 UP5KiCE40 UP5K**Type**MicrocontrollerFPGAFPGAFPGA**ADC speed**60 MspsUp to 64 MspsUp to 64 MspsUp to 64 Msps**ADC resolution**10\-bit10\-bit10\-bit10\-bit**TGC amplifier**AD8331 \(48 dB range\)AD8331 \(48 dB range\)AD8331 \(48 dB range\)AD8332 \(92 dB range\)**Onboard HV**No \(separate board\)YesNoNo**Form factor**Compact \+ PMODsLarge single boardRPi pHATRPi pHAT**Programming**C/C\+\+ \(Arduino\-like\)Verilog \+ PythonVerilog \+ PythonVerilog \+ Python**FPGA required**NoYesYesYes**Extensible**PMOD connectorsLimitedRPi GPIORPi GPIO**Cost**LowestMediumLowMedium\-high**Best for**New projects, education, fast prototypingUsers needing full FPGA flexibilityRPi\-integrated setupsWeak signal detection \(high gain\) **For new projects, we recommend the pic0rick**unless you specifically need FPGA\-level timing control or the 92 dB gain range of the lit3\-32\. --- ### [http://un0rick.cc/pic0rick#example-of-acquisition](http://un0rick.cc/pic0rick#example-of-acquisition)Example of acquisition A typical acquisition looks like this — the large spike on the left is the transmit pulse, and the smaller peaks to the right are reflections from your target:  --- ## [http://un0rick.cc/pic0rick#the-pic0rick-alongside-older-boards](http://un0rick.cc/pic0rick#the-pic0rick-alongside-older-boards)The pic0rick alongside older boards  --- ## [http://un0rick.cc/pic0rick#source-files](http://un0rick.cc/pic0rick#source-files)Source files All design files are open source: - **Hardware \(KiCad\)**: Main board, pulser board, HV board — in the[pic0rick repository](https://github.com/kelu124/pic0rick/) - **Firmware**: RP2040 C/C\+\+ source code — in the`software/`directory - **Documentation**: Published under CC BY\-SA 3\.0 --- ## [http://un0rick.cc/pic0rick#get-one](http://un0rick.cc/pic0rick#get-one)Get one - **Buy assembled**: Available on[Tindie](https://www.tindie.com/stores/kelu124/) - **Build your own**: All KiCad files and BOM are in the[GitHub repository](https://github.com/kelu124/pic0rick/) - **Questions?**Reach out on[Slack](https://join.slack.com/t/usdevkit/shared_invite/zt-2g501obl-z53YHyGOOMZjeCXuXzjZow)or email[orders@un0rick\.cc](mailto:[email protected]) --- ## [http://un0rick.cc/pic0rick#thank-you-to](http://un0rick.cc/pic0rick#thank-you-to)Thank you to - Abdelrahman - Lap --- ## [http://un0rick.cc/pic0rick#license](http://un0rick.cc/pic0rick#license)License This work is based on three previous TAPR projects,[the echOmods project](https://github.com/kelu124/echomods/), the[un0rick project](https://doi.org/10.5281/zenodo.377054), and the[lit3rick project](https://doi.org/10.5281/zenodo.5792245)— their boards are open hardware and software, developed with open\-source elements as much as possible\. Copyright Luc Jonveaux \([kelu124@gmail\.com](mailto:[email protected])\) 2024 - The hardware is licensed under TAPR Open Hardware License \(www\.tapr\.org/OHL\) - The software components are free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or \(at your option\) any later version\. - The documentation is licensed under a[Creative Commons Attribution\-ShareAlike 3\.0 Unported License](http://creativecommons.org/licenses/by-sa/3.0/)\. ## [http://un0rick.cc/pic0rick#disclaimer](http://un0rick.cc/pic0rick#disclaimer)Disclaimer This project is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE\. --- ## Table of contents