Laser Tag Robot Tank: An Introduction
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 more than 270°. The turret gearbox included a slip-clutch device for when the user attempted to rotate the turret too far. I wanted to use a slip ring for the turret wiring which would allow the turret to rotate endlessly in either direction. But this required a modification to the turret ring. On the Tiger tank, I tried to cut the teeth with a blade but I cut too much away, ruining the turret ring (unless I can find a way to re-mold the teeth). The other tank model (a German Leopard?) used a different mechanical design and I needed only to cut back some "stopper" plastic to make the turret spin 360°.
2). I wanted to replace the battery-pack with a battery holder, since I assumed I would get more power and life from my rechargeable batteries. This turned out to be more work than I anticipated, as I had to grind-away a significant amount of material to make room for the larger battery holder.
And ... that's pretty much where I stopped and spent my time doing other things.
Then, a few months ago, I started thinking about electronics again and remembered my Tank Project. I spent some time learning KiCad, so that I could get PCBs printed. I decided that I should create a daughter board to be placed in the tank turret. This would allow me to use a 6-wire slip-ring for the turret, instead of the more expensive 12-wire version. This board would be much simpler than the main board of the tank, so it seemed like a good candidate for my first PCB. Here are the image files produced by OSH Park:
I decided to use JST connectors to keep everything clean and modular. This is a really simple circuit: It has an incoming power line and 4-wire signal line (IR receive, IR transmit, SDA, SLC). It has four mounting holes. This kept the number of wires going through the slip-ring to 6. I added two resistors and a capacitor and called it good. After a couple of weeks, I received my three boards from OSH Park and I soldered one up and everything tested fine. The only trouble I had was that I made my wires into the JST pins too long, which pushed down on the male JST pints and, in one place, pressed a cooper trace off of the board. Anyway, globs of solder later, it worked okay.
Here is a photo of the three boards, one of them has components soldered on and is connected to the tank:
The above board is intended to be used with the IR Tracking Camera from RobotShop [http://www.robotshop.com/en/ir-tracking-camera.html]. Underneath, it's just a Pixart Wiimote camera but it includes a voltage regulator and oscillator and everything else the camera needs. You just supply it 5v and plug in your i2c lines and you are good to go. But ... it's $25. Also the form factor is a little bulky for my tanks. I figured if I already had the need for a daughter board, I could just modify the board to accept a Pixart camera directly.
This is the result of that effort:
So this is basically the same board as before but with the addition of the Pixart IR camera. It still only has six wires that need to go to the main board! OSH Park would not allow me to upload rectangular holes. It's possible that I just don't know how to do them properly. Anyway, each side of the Pixart camera has a rectangular mounting tab but my board has round holes that will (hopefully) accept these tabs. The camera is to be mounted on the underside of the board which will (hopefully) allow the camera to stick out above the turret while the board itself is contained within the turret. This board has only two mounting holes and they are spaced to (hopefully) slip over the two existing plastic studs in the tank. Precise fitment issues to be resolved (with a dremel, probably) when I receive my boards.
References:
http://www.instructables.com/id/Wii-Remote-IR-Camera-Hack/
http://www.robotshop.com/letsmakerobots/wii-ir-camera-standalone-sensor
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 more than 270°. The turret gearbox included a slip-clutch device for when the user attempted to rotate the turret too far. I wanted to use a slip ring for the turret wiring which would allow the turret to rotate endlessly in either direction. But this required a modification to the turret ring. On the Tiger tank, I tried to cut the teeth with a blade but I cut too much away, ruining the turret ring (unless I can find a way to re-mold the teeth). The other tank model (a German Leopard?) used a different mechanical design and I needed only to cut back some "stopper" plastic to make the turret spin 360°.
2). I wanted to replace the battery-pack with a battery holder, since I assumed I would get more power and life from my rechargeable batteries. This turned out to be more work than I anticipated, as I had to grind-away a significant amount of material to make room for the larger battery holder.
And ... that's pretty much where I stopped and spent my time doing other things.
Then, a few months ago, I started thinking about electronics again and remembered my Tank Project. I spent some time learning KiCad, so that I could get PCBs printed. I decided that I should create a daughter board to be placed in the tank turret. This would allow me to use a 6-wire slip-ring for the turret, instead of the more expensive 12-wire version. This board would be much simpler than the main board of the tank, so it seemed like a good candidate for my first PCB. Here are the image files produced by OSH Park:
I decided to use JST connectors to keep everything clean and modular. This is a really simple circuit: It has an incoming power line and 4-wire signal line (IR receive, IR transmit, SDA, SLC). It has four mounting holes. This kept the number of wires going through the slip-ring to 6. I added two resistors and a capacitor and called it good. After a couple of weeks, I received my three boards from OSH Park and I soldered one up and everything tested fine. The only trouble I had was that I made my wires into the JST pins too long, which pushed down on the male JST pints and, in one place, pressed a cooper trace off of the board. Anyway, globs of solder later, it worked okay.
Here is a photo of the three boards, one of them has components soldered on and is connected to the tank:
The above board is intended to be used with the IR Tracking Camera from RobotShop [http://www.robotshop.com/en/ir-tracking-camera.html]. Underneath, it's just a Pixart Wiimote camera but it includes a voltage regulator and oscillator and everything else the camera needs. You just supply it 5v and plug in your i2c lines and you are good to go. But ... it's $25. Also the form factor is a little bulky for my tanks. I figured if I already had the need for a daughter board, I could just modify the board to accept a Pixart camera directly.
This is the result of that effort:
So this is basically the same board as before but with the addition of the Pixart IR camera. It still only has six wires that need to go to the main board! OSH Park would not allow me to upload rectangular holes. It's possible that I just don't know how to do them properly. Anyway, each side of the Pixart camera has a rectangular mounting tab but my board has round holes that will (hopefully) accept these tabs. The camera is to be mounted on the underside of the board which will (hopefully) allow the camera to stick out above the turret while the board itself is contained within the turret. This board has only two mounting holes and they are spaced to (hopefully) slip over the two existing plastic studs in the tank. Precise fitment issues to be resolved (with a dremel, probably) when I receive my boards.
References:
http://www.instructables.com/id/Wii-Remote-IR-Camera-Hack/
http://www.robotshop.com/letsmakerobots/wii-ir-camera-standalone-sensor
Comments
Post a Comment