Alright, so today I wanna talk about this thing I've been tinkering with – my 'psi cars' project. Don't get too excited, it's not like proper psychic stuff, more like 'Pattern Sensory Input' cars. Or maybe 'Probably Slightly Insane' cars, given how much trouble they gave me.

It all started when I found a couple of old remote-controlled cars in the attic. You know, the cheap ones. And I had this little microcontroller board, one of those common hobbyist ones, just gathering dust. So, I thought, why not try to make these cars do something a bit smarter than just forward and backward with a clunky remote?

Getting My Hands Dirty

First things first, I had to take apart one of the cars. That was fun. Wires everywhere. Figuring out how to bypass the original controller and directly tell the motors what to do – that took a while. Lots of poking around with a multimeter. I’m pretty sure I shorted something once or twice, got that lovely smell of hot electronics. Classic.

Then came the 'psi' bit. I wanted the car to react to something, maybe my hand. I got this real basic light sensor – thought I could make it follow a shadow or a bright light. Hooking that up to the microcontroller wasn't too bad. The real headache was getting consistent readings. Sunlight, room light, shadows… everything messed with it. One minute it seemed to work, the next it was blind as a bat.

The Coding Struggle

I spent, I don’t know, a whole weekend just trying to write some code to make sense of the sensor data. My code is… well, it’s what you’d expect from someone who learns by breaking things. Lots of `if this, then that`, and a good amount of `why isn't this working?!` shouted at the screen. I tried to get it to follow my hand – if my hand cast a shadow, it should move. Simple, right? Nope.

For the longest time, the car would either sit there doing nothing, or it would suddenly jolt forward and crash into the furniture. Or it would just spin in circles. My cat was very entertained, I can tell you that. I must have tweaked the sensitivity values a hundred times. I even tried different sensors, like a cheap ultrasonic one, but that had its own set of problems with reflections and stuff.

A Little Breakthrough

Eventually, I kind of got a breakthrough. I realized I was trying to be too clever. I simplified the logic. Drastically. Like, 'if sensor value VERY low, then turn left. If VERY high, turn right.' Super basic. And I added a ton of delays and averaging of sensor readings to smooth things out.

So, where am I now with these 'psi cars'? Well, one of them kinda, sorta works. On a good day, with the wind blowing in the right direction and the lighting just perfect, it will vaguely follow my hand if I move it slowly. It’s not exactly autonomous driving, believe me. It’s clumsy. It’s unreliable. But hey, it moves based on something other than the original remote! That felt like a win.

What I Reckon I Learned

What did I learn from all this faffing about?

• Old RC cars are surprisingly hackable, if you're patient.
• Sensors are fussy little things. Really fussy.
• Simple code is often better than complicated code, especially when you're just messing around.
• And I definitely need to buy better quality jumper wires. The cheap ones are a nightmare.

It’s still a work in progress, obviously. Maybe one day I’ll make it actually smart. Or maybe I’ll just find another old toy to take apart. We'll see.