Wherein Matt attempts to build a war mech. Or possibly just a little hobby robot, depending on availability and cost of parts.
So, I have a long-term robotics project I’m putting together as I can afford the parts.
Here’s what I’ve managed to put together so far:
1x Beaglebone Black. It came down to either this or a Raspberry Pi, as I’ve got one of each. I decided to go with the Beaglebone in the end for two reasons – firstly it’s got a lot more in the way of IO pins, which means I can always drive LEDs and things directly from them if I want. Secondly, it’s only got a single USB port, which means I can keep the Pi for use as a computer using keyboard+mouse. It’s also slightly faster than the Pi in terms of processing power, and has onboard storage meaning there’s no need for a memory card.
1x Arduino. This is going to be the microcontroller for the motors.
1x Arduino Motor Shield. This can run up to 4 DC (or 2 Stepper) motors plus 2 Servo motors. Third party clone of this one from Adafruit.
1x USB Network Adapter. This will be used for remote control, I’m thinking a small webserver on the Beaglebone serving a page that can be used to issue commands.
Currently the Arduino is linked using the Beaglebone’s single USB port, but the next step will be using a pair of serial pins for comms instead. However, as explained here this requires a logic level shifter as the Arduino uses 5v pins while the Beaglebone uses 3.3v pins.
So, the shopping list (which may well change as I do more experimentation and research) currently consists of:
- Parts for chassis. Some Lego Technic might make a decent prototype.
- Motors. It’s looking like a pair of steppers for motivation, and a pair of servos to drive a manipulator arm or something. Will have to look into more motor outputs (a second arduino+shield?) if it needs any more than that.
- Sensors. A couple of distance sensors for navigation. Light and temperature would be nice additions if I can get them on. Gyro and/or compass would be fantastic… hopefully I can wire all of these directly to IO pins on the Beaglebone.
- Speaker. For audio feedback. Again, hopefully something that’ll wire onto the Beaglebone.
- Power Supply(s). I need to feed a pair of 5v inputs for the Arduino and Beaglebone, plus the motors. It’s best to run the motors off their own dedicated supplies to prevent feedback, plus it’ll allow the “brain” to keep working even if it can’t move any more (and maybe even to signal for help!). So, probably a split 5v for the circuitry plus a 9v for the motors. Battery housings might be the best option, so I can just fill them with rechargeable batteries (makes me wonder about adding a solar panel longer term, need to read up on how that can be wired in!)
Update 31-Mar-2014: Found this at Amazon, it looks perfect as it’s rechargeable and contains two 5V supplies and a 9/12V 🙂
- Wheels, tracks, or whatever to bung onto those motors. Stuff for them to turn.
- Some kind of cover. Obviously not much point designing this until the chassis is built and everything is hanging off it (although I have to admit I have something very specific in mind, if I can make all of this work…)