Man Is A Robot

To mix up the LTRT work a bit and take a break from circuits, I decided to go back to the problem of the turret ring. The turrets of the toy tanks are limited to a rotation of 350° or so. This is accomplished with both a tab underneath the turret and by,  on the turret ring, a solid section in place of teeth. Because I want my turret to rotate 360°, I filed away the tab with a Dremel and I cut crude teeth into the turret ring. The turret ring as installed in the tank. At bottom, the driving motor and gearbox is seen. I have two Hall-effect sensors installed here. One detects rotation of a magnetic disk that is installed on the motor shaft and is intended to as a rotational encoder. The other sits below where a magnet attached to the turret will pass and will be used to determine when the turret is sitting at its 0-degree position. A closeup of my crude Dremel work. Surprisingly, this still works. So, anyway, though my Dremeled turret gear DOES work, it's...

I received my turret boards from OSHPark. Here are OSHPark's generated images of the PCB. I immediately set to soldering enough components to test the 3.5v power output from the voltage regulator. But ... after soldering on some capacitors, resistors, the regulator, and a JST connector, I had no power. I double-checked the schematic and saw that I completely screwed-up the power connection to the voltage regulator. I cut a trace with an X-acto and soldered a jumper and hooked it back up. I had very little power coming from the voltage regulator and it was quickly too hot to touch. I unplugged it before I melted something. I'll have to go back to the schematic to determine why my jumper did not fix the power issue. I knew that I would have to perform multiple revisions but I'm disappointed to screw-up a board with such a basic mistake. I did not label my nets hardly on the schematic and I might have caught the issue if I had. My schematic for the main board is be...

To tackle the problem of turning off the IR beacon while the IR transmission was taking place, I typed words into Google and started finding some good stuff when I searched for "digital inversion circuit". I read a bit about switching regulators such as the MC34063 but quickly became intimidated. It seemed like more than I needed. Eventually I found a  page  on Sparkfun that talked about transistors and NOT gates. I ended up building this circuit using a NPN transistor, some resistors, and a capacitor. The Sparkfun page lacked actual resistor values so I sorta guessed at them. The 10uF capacitor maintains a voltage on the NPN base while the yellow LED is flashing, which I think is going to be important for my application. Scrubbing through the video on my phone, I was able to find a frame where both the yellow and red LEDs are illuminated. Not too surprising, really, but it makes me wonder how feasible it is to get an LED to turn off during the milli-second timefram...

So I was screwing-around with my the main-board schematics last night. They are almost complete. After the addition of a speaker (actually, a piezo element), I had three pins left over. I was trying to decide what I should use those pins for. I know that I want at least one LED visible on the outside of the tank, as a status indicator. The tanks I am messing with, they have four LEDs near the back of the tank and I can repurpose as many of those as I want. So I'll probably have three LEDs (Though I toyed with the idea of using the pins for the Echo lines of my sonar sensors, instead of tying those pins together with the Trigger lines. I dunno. It makes the software a bit more complicated, switching pin modes every time they are used. I really don't know if I will run into any timing issues by sharing the lines). And I played around with a NPN transistor and a piezo speaker for a while, I decided to take a shower and go to bed. So I was in shower and that's when I realiz...

Laser Tag Robot Tank is the first project of any size that I've attempted with an Arduino. I got an Arduino dev kit a few years ago. I made an LED blink. I bought a tracked platform and a motor controller and made a tank that pointed itself in random directions and bumped into things. I purchased a CMU cam  with the intention of making a robot that would chase a ball or something ... but I never got anywhere with that. In the winter of 2016 I saw "Fighting Battle Tanks" advertised on Amazon and I purchased a few. I've always liked tanks and I thought it would be cool to make autonomous battling tanks. These tracked RC toys use infrared (IR) signals to communicate, the same as your television remote or, for that matter, "Laser" Tag toys. I played with my new tanks and soon took them apart. I identified a few things that I wanted to modify: 1). The turret rings had a part where the teeth ended in a solid plastic area. This prevented the turret from rotating...