Embedded Journeys

In this post, I explore whether the Raspberry Pi Pico 2 can act as a rudimentary oscilloscope. Some theoretical considerations about the Pico 2’s ADC are presented. These are then put to the test through measuring HC-SR04’s echo pulses.

When I read about the presence of the USB controller on the RP2350, I got intrigued if I would be able to stream data from the Pico 2 board. I set out to use TinyUSB on the RP2350 and created a host application in Python to ingest the data. This post is about some of the key insights I gained during the development of a simple datapipeline: from the pico 2W USB device to the Python USB host.

This all started when I was trying to understand how my RP2350 would react when I wanted to read a memory address like 0x00000000 on the RISC-V and ARM cores. However, this sidetracked me into a deeper understanding of debugging the RP2350 with my Raspberry Pi Debugger Probe! At first, it felt like regular breakpoints were just ignored, if the program even started running at all! My attempts at running RISC-V and ARM cores revealed some subtle debugging behaviour.

Just a small post about how I’m making sure I can quickly get my Raspberry Pi Pico 2W with me when on a commute. A small assortment box carries all components I need to quickly set up a small development environment.

The HC-SR04 is a popular and inexpensive ultrasonic distance sensor that measures range using sound waves. In this post, we connect it to a Raspberry Pi, explain the electronics behind the Trig and Echo pins, build a safe voltage divider for 3.3 V logic, and write a simple Python script to read accurate distance measurements. Oscilloscope measured signals put theory to the test. We’ll also touch on accuracy limits, environmental effects, and how ultrasonic interference can impact your readings.