Picnics are fun. You fish a cooler bag from the back of a cupboard along with some half-forgotten freezer blocks from the ice tray and fit in as many sandwiches, sausage rolls, and cans of soda as you can. After grabbing some family or friends, you find a nice spot and eat outside. Wonderful, aside from the inevitable invasion by ants, but still great. What if you could take ants out of the equation, though? You could if you were somehow able to have a picnic out in the middle of a lake. Meet Yves Daigle and his raftBerry project.
The full article can be found in The MagPi 39
"The idea is to create a fully autonomous electrically propelled ľoating dock, controlled by a Raspberry Pi, to drive us around our lake," Yves tells us. As you can see from the resulting picture of Yves and some friends enjoying a meal on the floating dock, the idea has come to fruition.
As an aerospace engineer serving in the Canadian Air Force, Yves is used to creating complex equipment, so it’s no surprise that this side-project is not exactly simple as well:
"The control system has two available modes that can be selected via a switch on the console: manual or autonomous. The dock uses two static motors for propulsion that can also steer the dock via diļerential thrust.
"The Pi reads inputs via the GPIO from the arcade joystick, emergency shutdown button, and mode select switch. Each motor is independently controlled by five automotive relays, three of which are used to set the speed, and the remaining two are used in an H-bridge configuration to set the motors in forward or reverse. The GPIO output pins control a small eight-channel relay board, which in turn controls these ten automotive relays. The whole system, from motors to control panel, is designed to be removed from the dock after every trip, using a hand truck."
The whole thing took him a month to finish after he started to properly work on it and also includes a DVD player, a table, seating, and a camping stove. Less of a picnic, then, and more a floating campsite.
“Manual mode works flawlessly," Yves explains. "The relays do get quite hot and full speed appears to not be as powerful as it was with the original control head. I suspect the relays are nearing max load and are causing some voltage drops. I plan to acquire larger relays. The motors may be a little underpowered."
Automatic mode doesn’t quite work right now, but Yves is working on it. As well as using Raspberry Pis at home and on watercraft, he’s been using them in his job: "We have 22 of them performing various tasks at the moment. I’ve found that Pis are several orders of magnitude more cost-eļective than commercial alternatives. Saving taxpayer dollars is something I take quite seriously."
