Making a raspberry pi robot: part 1

The first step was deciding that I wanted to start this project. I have an idea: an image in my head. I'm sure the final thing will be nothing like that initial thought. But I'm looking forward to finding the way to wherever it takes me. Started writing here to document my process and things I learn.

I suppose I'm beginning by finding out how to begin. And that comes with challenges. I have a raspberry pi, but no way of plugging it in. Access to a 3D printer, even, but I've never done any meaningful CAD before. What software to use? What wires do I need? What kind of motors, from the huge selection on the internet? And then I'd need a motor driver. And probably more power. And wheels. And a body. So a lot more research needed.

A few months ago, I had a conversation resulting in an idea. Which led to a sketch. It was going to be small, tin can shaped, and talk to people in Shakespearian English. Mostly inspired by a robot called Gizmo - the only part I remembered of some sci-fi book I read a while back. I would implement text to speech with a little speaker, hopefully someday add a camera so it could do object avoidance and leg tracking to follow people. I watched some youtube videos, got some ideas. Bought a raspberry pi zero 2, then discovered it didn't have audio output. Read some articles about how to get around that, but then went home for a month over Christmas and ended up back at uni with a pi 4 we'd bought years ago.

I've just ordered an ethernet cable, should hopefully be able to plug it into the network in my room. I don't have a monitor, and while I could use the lab ones, it'll be nice to be able to work on it weekends and from home. So the next step is trying to get a raspberry pi working on my laptop. Then I'll deal with motors and a platform and all the other stuff I want to do. First, I need to give the robot a brain.

Update - I have tried to ssh the raspberry pi to my laptop via the router in my room, but it hasn't worked. Got unknown host. So I'm going to bring it into one of the computer labs tomorrow and try one of the monitors.

Update 2 - Doesn't work on any of the uni computers, but the guy in the library makerspace had a little router that I could connect it to. It worked up until I tried ssh. Permission denied (publickey). I spent a while researching this and failing to solve it, so I phoned home. Turns out my Dad, the last person to use it, had attached it to his computer. No way I could access. Although I am now going to burn the default raspberry pi software onto the sd card. So I have a way forward.

Update 3 - Just used the raspberry pi imager on the micro sd card. Hope it works. I'll try to connect to it again later. The makerspace is currently closed. In the meantime, because I'm really excited, I've been working on a voice recognition program in python that will hopefully be able to give the robot ears and a voice when I get it working! So far, I've got the voice recognition module up and running, although it needs some work to run smoothly and conversationally. But trying pyttsx3 as a text to speech module, and that isn't. I'm currently trying to find a way to install espeak - needed for the module but not working on my mac. If I can't fix it, I'll try a different method of text to speech, or try it on the raspberry pi when I get that up and running.

Update 4 - Ok. Just bought an ethernet to usb-c adaptor so I can connect to my laptop and work on it from home and at the weekend. That's working fine. It connects, and I can find the pi. But when I try to ssh, it can find the IP address and attempt a connection, but it won't accept the password. Any of the passwords I've tried. Even trying to set the password to default and rerun the imager doesn't work. I'll try again tomorrow. Should probably now be sleeping.

Update 5 - Got pyttsx3 working!! The conversations are slow, but it's working!!! I had to install an earlier version of python, then an earlier version of all the modules and libraries I'm using, and voice changes still aren't working, but it's a step forward. I've learned a huge amount from this. The problem was with nsss; I didn't even need espeak. But my computer is talking to me!!!!!

The raspberry pi still isn’t working.