Pico on usedbytes:Blog

M0o+ Shepherd's Pi

Mon, 13 Jun 2022 00:00:00 +0000

The last of the three “prescribed” challenges is Shepherd’s Pi.

In this challenge there are 6 sheep which need herding into a pen, and 3 wolves which must not be “killed” (knocked over).

M0o+ Nature's Bounty

Sun, 12 Jun 2022 00:00:00 +0000

After tackling Hungry Cattle, Nature’s Bounty is next on the hit-list.

Lots of videos/pictures in this post, because I think it helps a lot with explaining how it all works.

M0o+ Hungry Cattle

Sat, 11 Jun 2022 00:00:00 +0000

Hungry Cattle is probably the easiest of the three main Pi Wars challenges to do autonomously and so is the one I chose to tackle first.

The basic premise is delivering “cattle feed” (rice) to three troughs, placed at known positions within the arena.

M0o+ Computer Vision

Sun, 29 May 2022 00:00:00 +0000

To be able to locate the different game pieces in the Pi Wars challenges M0o+ has a very basic camera.

M0o+ is using a Pico for all the processing, so there’s really no chance of porting OpenCV to it. There are other frameworks - even some machine-learning ones like TFLite - which could work on the Pico, however having had success with hand-coding my own routines for Mini Mouse, I decided to do the same this year.

M0o+ Software Overview

Sun, 15 May 2022 00:00:00 +0000

I’ve written a number of posts now about different “building blocks” which make up M0o+:

There’s one crucial element missing from that list, which is needed to turn a collection of parts into an actual functioning robot than can compete in Pi Wars: The Software.

M0o+ Boom - Part 3

Sun, 08 May 2022 00:00:00 +0000

Last time, I derived the Forward Kinematics for the boom on M0o+. If you haven’t read the first two posts, then this one won’t make much sense (and I don’t want to repeat myself 😀):

M0o+ Boom - Part 2

Sat, 02 Apr 2022 00:00:00 +0000

This post is the second in a trilogy detailing the boom on my Pi Wars 2022 robot M0o+.

In the last post, I wrote about the mechanical and electronic design. In this middle post, I’ll be describing the equations which let me find out where the end of the boom is, and next time will go into the equations which let me control where the end of the boom is.

M0o+ Boom - Part 1

Mon, 28 Mar 2022 00:00:00 +0000

My Pi Wars at Home 2022 robot M0o+ is intended to resemble a telehandler (long-reach forklift).

Image credit: Jacquesbotha, CC BY-SA 4.0, via Wikimedia Commons.

A fairly crucial part of a telehandler - the thing that makes it a telehandler, really - is it’s boom, which the forks (or other tools) are attached to and can lift and extend.

Pico PIO Camera

Sat, 19 Feb 2022 00:00:00 +0000

This is a lengthy post which goes into lots of detail. The tl;dr is that the code is here: https://github.com/usedbytes/camera-pico-ov7670

In this post I’ll describe how I went about connecting an OV7670 camera module to the Raspberry Pi Pico that drive’s my Pi Wars at Home 2022 ‘bot M0o+. It’s all wrapped up in a separate library which should be easy-ish to incorporate in other projects.

Trying to get this camera working was the very first thing I did, as a sort of Pico “feasibility study” to decide if entering a Pico-based robot was practical. Initially I just bit-banged the interface and did get some results without too much effort, but things have escalated a fair amount since then:

M0o+'s Chassis

Sun, 23 Jan 2022 00:00:00 +0000

M0o+ is my Raspberry Pi Pico-based robot entry for Pi Wars at Home 2022. This post details what I’ve settled on for the basic chassis of the robot.

Rebound (top)

As I wrote in my initial post for the project, I had originally hoped to re-purpose an ancient RC car chassis to be the basis of my robot.

Sadly, it became apparent that all of the things which made it so much fun as an RC car when I was a child, made it almost entirely unsuitable for Pi Wars.

ESP32 WiFi/Bluetooth Bridge

Sun, 26 Dec 2021 00:00:00 +0000

M0o+ is my Raspberry Pi Pico-based robot entry for Pi Wars at Home 2022.

A Pi Wars robot needs to be remote-controllable, and network connectivity is extremely useful for telemetry, debugging etc. As the Pico doesn’t natively have any kind of wireless connectivity, I’m using an ESP32 to provide that functionality. It connects to a bluetooth gamepad, relaying controller input to the Pico, and acts as a WiFi access point to provide network connectivity.

Pico serial bootloader

Wed, 01 Dec 2021 00:00:00 +0000

My Pi Wars 2022 entry, M0o+, is powered by a Raspberry Pi Pico, which itself is powered by the RP2040 chip.

The RP2040 has a built-in boot ROM with a USB bootloader, which allows the chip to show up as a USB flash drive for uploading code. This is usually a very convenient interface, making it extremely quick and simple to upload code to the device.

However, in a Pi Wars robot, I don’t want to have to bring the Pico back to my computer and plug it in to iterate on the code - I see it as essential to be able to download new code to the robot wirelessly without needing to touch it.