Pico pio uart dma rs485

thomasfla·pico-pio-uart-dma-rs485·hardware/quadRS485pico/quadRS485pico.kicad_pcb

About the Pico pio uart dma rs485 PCB

Pico pio uart dma rs485 is an open source RP2040/RP2350 PCB design by thomasfla, published on GitHub under the BSD-3-Clause license. It is a 2-layer board measuring 50 × 55 mm, with 19 components from 7 distinct parts.

Its main chip is the Pico, from the RP2040/RP2350 family. Other key parts include the THVD2450DRBR. By type, the board carries 5 ICs, 5 connectors, 4 capacitors, 4 resistors and 1 transistor.

From the project

Implementing 4x RS485 using pipico PIO and DMA

Implementing multiple channel RS485 using Raspberry Pi Pico PIO and DMA. This was inteded for low latency comunication with robotics actuator and sensors.

- For half-duplex RS485: only one device transmits at a time. - The OE (Output Enable) pin controls RS485 driver direction. - Supports multiple channels via separate PIO state machines. - Tested at high baud rates (12.5 Mbps and likely higher). - Waits for response with a configurable timeout. - End-of-frame detection based on silence (similar to Modbus). - Fully offloaded TX and RX: the CPU is not involved during transmission and…

Main components on the Pico pio uart dma rs485

THVD2450DRBR Pico

Pico pio uart dma rs485 bill of materials (BOM)

19 components, 7 distinct parts.

Qty	Part	Footprint	Refs
4	THVD2450DRBR	SON65P300X300X100-9N	IC1, IC2, IC3, IC4
1	Pico	RPi_Pico_SMD_TH	U1
1	DMG2301L	SOT-23	Q1
4	Conn_01x02_Pin	Hirose_DF13-02P-1.25DSA_1x02_P1.25mm_Vertical	J1, J2, J3, J4
1	Conn_01x06	Hirose_DF13-06P-1.25DSA_1x06_P1.25mm_Vertical	J7
4	C	C_0603_1608Metric	C1, C2, C3, C4
4	120	R_0603_1608Metric	R1, R2, R3, R4

Pico pio uart dma rs485 design files

The KiCad project lives in the thomasfla/pico-pio-uart-dma-rs485 repository on GitHub; these links point at the commit this page was built from.

Pico pio uart dma rs485: common questions

What microcontroller does the Pico pio uart dma rs485 use?

The Pico pio uart dma rs485 is built around the Pico, from the RP2040/RP2350 family.

How big is the Pico pio uart dma rs485 PCB?

The Pico pio uart dma rs485 measures 50 × 55 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Pico pio uart dma rs485?

19 components, from 7 distinct parts. The full bill of materials is listed on this page.

Where can I download the Pico pio uart dma rs485 design files?

From the thomasfla/pico-pio-uart-dma-rs485 repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Pico pio uart dma rs485 design in my own project?

Yes, under the terms of its BSD-3-Clause license, which thomasfla chose for the repository.

Can I test firmware for the Pico pio uart dma rs485 without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RP2040/RP2350 firmware against it before you order a PCB.