Or, more accurately, my adventures in creating Kevin.
I saw a YT video with a cute little robot that had a camera on it, and I thought I might want to make one. It was 3D printed, which I could have done, but prints take a long time, and a chassis with two 12v motors was cheap, so I decided to go that route. Kevin needed a camera, obviously, so I got an ESP32 WROVER dev board that had a good number of spare pins, and a backup ESP32 Cam board, which I’ll use if I must, since it doesn’t have enough pins for the two servos and the ultrasonic sensor, or anything else I might want to put on.
The camera part was pretty easy to get into ESPHome, but the picture was awful, even for a 2MP camera on a board that cost so little. I looked more closely at it, aaaand…it was glued crooked. In the factory, they set the lens focus to “infinity” (…and BEYOND?), and then glue it in place. I tried cutting through the glue with a small utility knife in hopes of unscrewing the lens and re-positioning it, but it was taking too long, so I said to hell with it and “liberated” the camera off the other board. I’ll mess with it later, maybe, or order another one from Ali for three bucks. Don’t care right now. So, the camera works, I can use it in HA, and the board doesn’t get too hot…we’re good.
The “winter storm” (eyes rolling) delayed the chassis I’d ordered from Amazon. It was supposed to have arrived on Friday, but by Saturday, it was still in the sorting center Kansas City MO, so I knew that wasn’t going to happen. No big deal; it’s not like I have nothing else to do. Finally, it showed out for delivery on Tuesday. I waited, and at 1850h, poor old Angie finally made it. She’s two years from retirement, and had been working for 12h. Someone needs to kick DeJoy repeatedly in the nuts, but that’s beside the point. For the record, I’d volunteer. It was by then too late to start assembly, so I just looked in the box. Seemed pretty straightforward; I wasn’t sure what the bunch of tiny screws were for, and I’m still not (the instructions say they’re for the track, but the track has no screw holes??), but it ain’t rocket science, so I decided to figure it out in the morning.
The instructions are a single page, printed in black and white. It’s a good thing this wasn’t complicated because colour pictures printed in black and white lose a lot of detail. They also had instructions online; clearly what they’d printed for the box insert. I read both, and while the words themselves were English, the instructions were not English. “Remove the track first and remove the excess parts.” What? Remove the track from what? It’s not attached to anything–how can I remove it?! “Adjust the suitable length and install the track. (Pls use the tool to cut off the spare tracks if it is too long).” Not joking…the instructions say, “Pls”. Okay, use what tool to cut off what part of the tracks? The genuine chineseium multi-bit screwdriver thing? Maybe? I look closer, and they’re just pins. Okay, so we’re not cutting; just removing links. One of the screwdriver bits fits the pin hole. I can do that.
I needed a plastic plate to keep the pin ends on the back sides of the boards off the metal chassis, and also so I’d have somewhere to mount the boards, so I made a quick rectangle with low sides. Rather than piss around, getting exact measurements for each hole in the chassis base, some of which I won’t even use, I’ll just mark them and drill through the print. Cheating, yes. Care? No. I’m thinking, “That’ll take a while to print, so I’ll work on the motors.” Famous last words. I have no female spade terminals that are small enough for the motors, which had never occurred to me, so I have to solder them directly. That’s not how it’s supposed to work, but as long as I get current, I don’t give a damn how it gets there. I did some fairly questionable soldering to get the wires on, and covered the connections with shrink tube. The motor driver is mostly straightforward; two terminals for positive and negative of each motor, one connection for 12v, one for 5v, and one for common ground, then four pins that connect to the board for control. I’m not sure what the 5v in is for; I think it may power the chip for control, and the 12v powers the motors directly. IDK whether the board I’m using can supply 5v, but I guess if it can’t, I can use a step-up regulator; I’m pretty sure I have some somewhere. Then again, a nap sounds rather appealing right now, and my print has another hour and a half left to go. Romans used to nap a lot, I think, and that’s why Rome wasn’t built in a day. Kevin won’t be, either.
