FPV robot

So the last power distribution board I made was a bit of a mess to say the least... It worked, but I really wanted to make a proper PCB. That way, it wouldn't look so janky, I could getter better current flow, nice mounting holes, and get a place to put the voltage regulator. 

That's where PCBway came in. I'm guessing the rep saw the previous board and decided I needed some help :) 

Any ways, I used easyEDA to draw up a schematic and board, sent it to PCBway and a week later these bad boys appeared in real life! I'm super pleased with the quality of the boards and the turn time on the order. 

A couple main things I was trying to achieve in the design:

• large pathways for current to flow (I have asperations of using this on some larger builds in the future)
  • I did this with polygon pours on the board
• spot to mount voltage regulator and have it's voltage distributed separately
  • I didn't think about the full size of the VR on this and needed to give it some more space. Thankfully I have a 3d printer and made some standoffs
• pads to solder wires directly to instead of using the screw terminals
  • I thought I was being clever by making them use the same pads as the screw terminals, but it was kind of a pain to solder to, I'll make them separate in the next iteration

Alright, so this update has a little less progress than I would like. I was really close to being able to drive a robot through FPV, but then I set it on fire….

I started out by spending an unfortunately long time contemplating how to mount all of the electronics. Decided to go with zip ties on to a board that has holes that are spaced out every half inch. I could have bolted them to the board, butttttt zip ties are so much quicker to use, and they won't loosen up from vibration!

Speaking of laziness, I decided I wanted to try and get something moving as quickly as possible and grabbed a chassis I used in a previous project. It had 4 metal gear TT motors that were already hooked up to a Adafruit motor shield.

I also used the control code from that previous project. (leave a comment if you want a copy!) It sets up the esp32 to broadcast a wifi network that I connect to with my desktop. The Desktop computer is running a python script that sets up a UDP socket to the esp32 to send commands. Right now I just have it set up to send the axis values from an old usb Joystick I had laying around.

The bot was driving around on the first try butttt then the second time I plugged in the battery, the voltage regulator on the esp32 caught on fire…. It was a literal fire, tons of smoke, a little red dot of flames and a terrible smell! This probably happened due to putting too much voltage on it from the battery. The device recommends 6-12 volts input, and I was feeding it 12-13V from the fully charged battery. Thankfully I have extra esp32s and if I really really wanted to I could probably replace the voltage regulator on there. I'm going to find a external 6v voltage regulator to power the esp32, and the servos I'm planning on using in the future.

Here's all the parts that I'm using in this post. I included an affiliate link for each item, if you decide to click on it, next time you buy something from amazon a small percentage will be sent to me to fund my next robot project! No extra cost to you!

(link to blog https://rcrobot.org/?p=106)

Have you ever had a project idea sitting in your head that sounds like it'd be awesome but you just never had the motivation to do it? I've had this idea of making an First Person View (FPV) robot for LITERALLY years! Last year I finally broke down and bought and wired up the components for FPV, but I never stuck them on a chassis. That could have been the end of it, BUT a couple days ago, I saw that Hackaday was running a new contest and creating a FPV vehicle!!!!!! https://hackaday.io/contest/188273-2022-fpv-contest  It's the perfect kick in the butt to get me to build this bot!

Last night I gathered up most of the electrical parts that I'm going to need:

• FPV transmitter
• FPV headset
• Antenna
• Battery
• ESP32 dev board
• Motor controllers 

I also soldered up a power distribution board with 8 outputs which will hopefully be enough. I'm not used to using perf boards which is my excuse for how ugly the soldering ended up being for this. I started out by just trying to put a glob of solder and running that between the tabs, but it wasn't flowing how I wanted and turning into a giant mess. I ended up grabbing some stranded copper wire and using that to guide the connections. Still a giant mess, but I double and triple checked that there weren't any shorts and then I covered everything in hot glue to make sure it stayed that way.

Next steps are going to be making a distribution board for the esp32 to sit on and then mounting all of the electronics on a board. I also need to find a power regulator to drop the 11 volts from the battery to 3-6V to run the servos.

Here's all the parts that I'm using so far. I included an affiliate link for each item, if you decide to click on it, next time you buy something from amazon a small percentage will be sent to me to fund my next robot project! No extra cost to you!