I started off this project wanting to use the Mr.Basic 4wd microcontroller chassis, but after 2 bad experiences with them having so much resistance that they couldn’t turn their wheels, moved to a slightly beefier 4 motor chassis. I got both a clear and black acrylic set of these from eBay (China), and have found them both to be of a much higher quality.
Parts list for my project:
Funnily enough, you will need a Raspberry Pi for this. Get one from RS electronics / Amazon / eBay etc. About £25
Raspberry Pi case
This “Environmentally Shell Kit Box For Raspberry Pi” case from oig.buy on ebay is the same style as the clear chassis I got, and provides very easy access to all parts of the Pi whilst protecting the top and bottom. Around £3
“Environmentally Shell Kit Box For Raspberry Pi” – eBay
1A micro USB charging cable
Good for powering the Pi or recharging the mobile phone battery pack that powers the Pi. I picked some up on eBay for £4.50.
I picked up a couple of Logitech B910′s from Scan’s eBay store for £45 a pop, after using an old Microsoft lifecam, which worked fine, but the quality wasn’t so great, but you can pick them up for about £6.
The Hello Kitty webcam that Nick favoured
USB WiFi adapter
Eximax make great USB WiFi adapters that work natively on Mac and Linux (as well as Windows), and we found these to be awesome – as they just worked. It looks like Edimax recently just released a new black version, which I picked up for £15 on eBay. I also got a white, fairly new one that was a dongle plus antenna (all in one), and Nick used a white just antenna model, and all 3 models have been brilliant.
12000 mAh mobile phone battery charger
I bought a couple of 12000 mAh mobile phone backup battery chargers to power my Pi when it goes mobile, and they last for somewhere near 8 hours. They are charged by a mini/micro USB cable, and output 1 and 2 amps over USB. Each cost around £17, and came with many little adapters to charge a variety of different phones, including micro USB for the Piberry Ras.
Around the £20 mark from China, I got 2 x 4WD, 4 motor chassis. [Clear one] [Black one]
Raspberry Pi Cobbler GPIO Super Start Kit from 4tronix_uk’s eBay store.
Including a huge breadboard, Adafruit cobbler cable and header, switches, resistors, LEDs and jumpers, the Cobbler Super Starter Kit was very useful starter kit full of essentials for messing around with the GPIO pins, and at £22, didn’t break the bank, and no soldering was required.
Raspberry Pi Cobbler
Including cable and header to extend the GPIO pins of the Pi to the breadboard, very good one made by Adafruit, although others are available such as this split one by Mallinson. I have one of each, but am yet to use the Mallinson one.
Mallinson GPIO Connector. Like Adafruit’s, but split at the end.
A 400 point breadboard is sufficient for the cobbler and motor chip.
Male to male jumper cables
I got a pack of 65 in my super starter kit, plus more from Maplin. Could make them yourself with bits of wire, but its handy to have the jumpers for quick prototyping.
LEDs and resistors
Handy for troubleshooting and emergency lights. I used some 20,000MCD super bright blue LEDs for my emergency lights, with 330 Ohm resistors, but they also seem fine without resistors, and a lot brighter. Waiting on some super bright whites for my headlights.
L293D motor control chip
I just put the motor chip straight onto the breadboard, straddling the central divide. They cost about £3 a pop, and one chip can control two separate (sets of) motors, at different speeds, if you have two pulse width modulation outputs on the device (for the Pi, you would have to do one in software).
Red and black wire
Wire is always helpful with electronics.
8 AA battery holder
To provide power for the motors
8 x rechargeable AA batteries
I already had a set of 2600 mAh ‘hama’ AA batteries (cells) and a charger that I got from 7dayshop many moons ago. I managed to find another very similar set on eBay for £13. These high capacity AA cells have kept my Pi driving on and off for a week now, and kept my Xbox 360 controller going for months of light use. Heavily recommend getting rechargeables and a charger – saves the environment and you buying tons of batteries.
Pretty handy to have:
- Wire cutters
- Wire strippers
- Tape/sticky velcro
- Soldering Iron, solder, safety glasses etc