The ESCs need Pulse Width Modulated (PWM) signals to then control the motors. PWM is relatively easy to understand and there's a great webpage on Wikipedia.
The Gadgeteer board I have gives outputs PMW signals so life is good :) Apart from the usual problem, not enough ports on the Gadgeteer board!
Along comes my friend! Pulse InOut from GHI Electronics.
What's lovely about this board is that it can support eight input and output PWM signals!
I only need the four output PWM signals however I'm thinking perhaps the inputs could be used for ultra-sonic sensors to help automated landing and/or obstacle avoidance. That'll be for later on in the project :)
Wonderfully, the Pulse InOut board indepently generates it's own PMW signals from a command rather than forwarding on a signal from the Gadgeteer board. Why is that cool?
If the code on the Gadgeteer board hangs then the motors still get their signals!!! I love this fail safe(ish) approach!!!
Safe Landing
Perhaps I might (later on) code for the chip in the Pulse InOut board for the case if the Gadgeteer board code does hang.
I'm thinking along the lines if the Pulse InOut does not receive any PWM commands from the mainboard for say 10 seconds then it gives equal power to the motors to hover and then slight decrease in power to enable landing.
Buying Time
I can't wait to get the board and start coding for it! I placed the order with Proto-Pic a few days ago and being Easter there will be a few extra days wait. Hopefully it'll be here before the weekend! Yea!!!
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