Our progress towards a $79 UAV mod kit for toy RC blimps is going well. We've now got a much better, two-sided PCB board that we're having fabbed. It's smaller, has more features and now integrates the IR sensors on the same board (Eagle schematic here; mask files here)
The board is an Arduino (ATMega168 CPU) clone at heart (we call it "Blimpduino"), with:
--Four motor drivers (two 2-motor chips)
--Four IR sensors and associated supporting components
--Ground-based IR beacon
--A choice between rechageable (more expensive) and non-rechargeable (cheaper) Lithium batteries
--Port for Ping))) ultrasonic sensor
--ISCP and FTDI programing ports
Pretty cool--a complete blimp autopilot and sensor package (with one ground beacon) for $79! Don't place your orders yet--we've still got a lot of sourcing and testing still to come--but I'm looking at having it ready for Christmas ;-)
Ah. Good idea. The original Pololu IR transceivers had that functionality, but we nixed them on cost, weight and size reasons. Maybe the Vishay transceivers would allow us to get the same functionality without those tradeoffs--what do they cost each?
Just to clarify, pins 23-28 are all dedicated analog inputs on the ATMega168 (see datasheet), so they would only be suitable for analog sensors such as touch or light. We only have one free digital I/0 pin, which I will make available for digital sensors or GPS.
If we go to a surface mount board, we can switch to the 32-pin version of the ATMega, which would free up some more I/O pins. That kit would cost a bit more (perhaps $99) since we'd have to ship the board in finished form. We'll see how much demand there is for that...
You read my mind. I've been redesigning the board to add connector blocks for those extra pins so you add additional sensors. Just adds a few pennies to the cost, and won't change the final price..
Neat project, very impressed. It's basically an Arduino at heart, so maybe you should retain some easy access to the spare CPU pins? It looks like you're not using pins 23-28 on the CPU for anything (at the moment?). Perhaps you could expose those in a jumper block (in the same way as the Arduino) so that if someone wants to add a compass or a GPS at a later stage, it's easier..? I know you're trying to keep it under the magic US$100 mark, but it won't be a big incremental cost?
Thanks for the comment. The RC blimps have the capacitors already installed on their motors, so we don't bother with them on our board.
What PCB design software do you use? I find the Eagle Lite really non-intuitive. (And its help file doesn't work on Vista--along with being pretty useless anyway)
Comments
The ground beacon is IR transmit-only. The blimp is IR receiver only. We use the Vishay TSOP34156 IR receivers on the blimp board.
I don't really see the advantage of the combined package, because we only need half the components in each case.
If we go to a surface mount board, we can switch to the 32-pin version of the ATMega, which would free up some more I/O pins. That kit would cost a bit more (perhaps $99) since we'd have to ship the board in finished form. We'll see how much demand there is for that...
You read my mind. I've been redesigning the board to add connector blocks for those extra pins so you add additional sensors. Just adds a few pennies to the cost, and won't change the final price..
Thanks for the comment. The RC blimps have the capacitors already installed on their motors, so we don't bother with them on our board.
What PCB design software do you use? I find the Eagle Lite really non-intuitive. (And its help file doesn't work on Vista--along with being pretty useless anyway)