Blog - All Comments

RE: Pico low jitter PID controller

Jan Cumps — Sun, 25 Oct 2026 19:09:20 GMT

I tried this same example, on the RISC-V cores of the RP2350

The comparison is unfair at the moment because:

I don't have a fixed point library for the RISC family (yet), so I have to use floating point math
the RISC cores don't have an FPU, They can't use the ARM FPU, so have to do all floating point math in C on the CPU, that doesn't have floating point instructions.

The PID loop time is 11 µs.

I'll try to find q fixed floating point lib for the RISC, either a Q15 or Q31 version. The results should be fairly similar to ARM then.

RE: Pico low jitter PID controller

shabaz — Sat, 24 Oct 2026 14:43:18 GMT

Hi Jan,

Neat project. This seems like a really clean way to drive the PID updates, all clocked from the ADC rate! Also, interesting how you ran the function from RAM for lower latency. I didn't know that was possible.

RE: Pico PID controller without floating point using DSP C++ fixed point API

Jan Cumps — Sat, 24 Oct 2026 08:44:19 GMT

In this test code, a timer makes the PID loop run, and the loop performs ADC.

A better approach is to time the ADC sampling, and let an ADC interrupt kick off the PID as soon as the sample is in.

On a Pico, you'd make the ADC run timed, in the background by:

adc_set_clkdiv();

adc_run();

And you 'd kick off the PID cycle by setting up an "ADC finished" interrupt:

adc_fifo_setup();
adc_fifo_drain(); 
irq_set_exclusive_handler(); 
irq_set_enabled();
adc_irq_set_enabled()

And then in the ADC handler, you retrieve the FIFO sample and run PID.

uint16_t sample = adc_fifo_get();
// run the pid

The main loop () is not involved.

RE: I wrote a hands-on Raspberry Pi Pico 2 project book — free review copies for embedded developers

PeterDev — Thu, 14 May 2026 09:26:55 GMT

Hi Michael,

I just picked up a print copy of your book following your post.

Regarding the GitHub repo you mentioned: Since the code snippets in the printed version are sometimes hard to read ,would it be possible to host the full source code there?

It would be a great help for following along.

Thanks!

RE: I wrote a hands-on Raspberry Pi Pico 2 project book — free review copies for embedded developers

iggytung — Tue, 14 Apr 2026 08:53:26 GMT

Thanks for sharing. I’m interested in RP2350 program but couldn’t find more examples

RE: Introducing The New Raspberry Pi 5 - 3x Faster, 2.4GHz, VideoCore VII GPU, RTC, Gigabit Ethernet, 1GB, 2GB, 4GB, 8GB RAM

libhacker — Thu, 09 Apr 2026 10:21:03 GMT

It's amazing how many things you can update on the board without having to make it bigger. As they said stuff had to be shifted around. But the CPU is a huge improvement.

RE: Using CLion for Easier Coding with Pi Pico and C/C++

shabaz — Sat, 07 Mar 2026 04:11:16 GMT

Just updated the blog with steps I took in 2026 to get CLion working with Pi Pico. It's a little easier than the previous documented steps.

RE: I wrote a hands-on Raspberry Pi Pico 2 project book — free review copies for embedded developers

shabaz — Wed, 04 Mar 2026 16:45:02 GMT

Currently some issues with both the Kindle sample and the PDF sample (formatting; every code section has the issue from what I can see):

RE: I wrote a hands-on Raspberry Pi Pico 2 project book — free review copies for embedded developers

cstanton — Tue, 03 Mar 2026 22:56:49 GMT

This's pretty cool, thanks for sharing.

Do e14 Community members get a discount? ;)

RE: C++ write your own stream class - part 2: a working Pico UART IO stream (embedded friendly C++)

Jan Cumps — Sat, 03 Jan 2026 14:17:34 GMT

added a ready-to-build repository for the example code: https://github.com/jancumps/pico_uart_stream_example

RE: OO Library to handle Pico PIO relative interrupts: usage and example

Jan Cumps — Wed, 17 Dec 2025 21:21:09 GMT

I like to be confident of my designs - but I've been around [emoticon:c4563cd7d5574777a71c318021cbbcc8].

Dealing with real time and frequent interrupts can be challenging.
I'm using an OO design here - an approach that's often flagged as risky for embedded designs.

I trust the code, but prefer to back that up with real world data.
I tested this design on a RP2040, and an RP2350 (in ARM and RISC mode), for a month.

With all PIO state machines used (8 on a RP2040, 12 on a Pico2), there was not a single interrupt missed, and no memory leakage.
I also tested this with fewer than max PIO state machines deployed. The code has behaved stable all the time.

It shows that C++26 and GCC are stable. But it also shows that the Pico controllers - and the Raspberry Pico SDK, are sound.

RE: Use the Pico RP2350 in RISC-V mode without Pico VSCode Extension: build

Jan Cumps — Mon, 15 Dec 2025 20:41:54 GMT

It looks straightforward once you have a working makefile (like the one in the main post here). But I struggled to get existing projects working with the RISC-V cores, without the extension. And once I got the build working, I had debug issues.

The work in the post above is from 1 morning and 1 evening of development. I got a working build before my workday started. And a working debug in the evening, after the day job.
But before today, at least 10 failed and abandoned attempts, in a period of - say - a year.

The final exercise today - after resetting my brain a bit, because of rabbit holes - almost wrote itself.
Without those mishaps this would not have been possible. The human brain is a strange vehicle ...

RE: Use the Pico RP2350 in RISC-V mode without Pico VSCode Extension: build

scottiebabe — Mon, 15 Dec 2025 18:13:25 GMT

floating point on the rp2040 is so slow, the new rp2350 is a wonderful product.

RE: modern C++ on a Pico: use C++ Standard Library algorithms - embedded friendly

pvit — Tue, 18 Nov 2025 08:03:41 GMT

I'd suggest you take a look at the Embedded Templates Library https://www.etlcpp.com/. It's more focused on embedded-specific demands and portability between c++ standards.

~ the same as std, but without dynamic allocations everywhere, with backports of new features like string_view to ancient C++11 compilers when nothing better is available on your target MCU. And of course, both can be used at the same time, if needed.

RE: C++ write your own stream class - part 2: a working Pico UART IO stream (embedded friendly C++)

DAB — Mon, 17 Nov 2025 19:49:22 GMT

Nice post Jan.