The path of least resistance

I got to play with an mBed at work yesterday, it's pretty awesome.

I'm in the process of designing a small PIC board that I can stick a number of different footprints on to take a range of devices. I was going to allow flexibility for plug in expansion (like the Arduino shield) but still keeping it small and simple, and being compatible with breadboards. The plan was to use it on the UAV and a couple projects for my motorbike.

I wasn't happy with the cost of the Arduino. It's too big and expensive to leave in many simple projects (especially if using shields). The smaller versions have no on board USB, which means more faffing. There is a slightly bigger version that does have USB on board, but that's only a few £ less than an mBed and doesn't do USB host, CAN or Ethernet (unless I'm mistaken).

So I'm going to simplify my PIC board, for simpler projects, keep it smaller and cheap (10+ for the price of an mBed?). When I need USB/Ethernet/CAN, I'll use an mBed.

Happy bunny

I've actually managed to get something done! OK it's nothing major, but I feel I've accomplished something. Something I haven't felt for a long time, so I'm a happy bunny. All I've done is added three buttons; up, down and home, along with adjustable end stops and home position to my bit banging servo code. I also upped the refresh rate to about 80Hz, from previous experience. I can substitute an EDF and could set the home position to be just below the point where the whole thing gets light on it's feet.

But I need to close the loop, so will dig out the ultrasonic rangers and try remember how to setup the ADC to read the range signal(s). I know, it's going to very crude...

Haven't had any photos recently, so thought I'd change that:

Microchip ICD2, my own dev board and standard servo.

ICD2 sorted (& plan B?)

Got it working last night by uninstalling MPLAB 8.6 and MPLAB X, then deleting the microchip folder. Installed 8.63 and X again, went through the driver installation and it connected!

So now I can mod my bit banging servo code for controlling an EDF.

But wait... thinking about it last night, there's no point doing all the low level stuff in the uC, that's just going to delay things even further. I need to use an external servo controller that I just talk to over serial comms. It takes a lot of overhead away from the main processor and makes servicing each task a lot simpler. Sound like a plan?

ICD2 is OK

Plugged it in, had to install drivers, but MPLAB connected to it fine.

Is it a Win7 problem?

Still no luck

Last night, I tried reinstalling ICD2 drivers, which didn't work. Then I downloaded and installed MPLAB X (Beta), no change. I can only assume my ICD2 died since I last used it!? Then I got bored so went and watched four or five episodes of The Big Bang Theory (thanks for the loan, Gary).

I'm going to take the ICD2 to work today and try it on my machine there.

Been too long!

I have a little time before my studies start up again, so thought I'd try to get something together to control an EDF for crude testing. I grabbed my PICDev01 board, ICD2 and a PSU and sat down to get to grips with MPLAB IDE again (it has been a long time).

So far I'm not having a lot of luck. It's nothing I haven't done before; I think the ICD2 drivers haven't installed properly and the project won't build (new HDD since last used too!). I can see the advantage of having everything in the cloud, as the mBed does; saves these sort of setup hassles...

Mr Parker - I thank you...

I got a good telling-off today, by Mr Parker. He said I'm spending all my time planning my revision timetable and not actually revising (working on the L/G - he wants to see it fly). I should just use a couple of bent wire coat hangers and be done with it.

So, I got home tonight, determined to get a chunk of work done on the legs. I want to get some gear in place for the thing to sit on, so it's doesn't rock and skate around (in theory at least). But you are right, Mr P, so I worked like a crazy man...

I got the rear vertical pieces cut out, sanded, drilled and tapped, then drilled the Alu knees of the rear pair. In a flash of genius I solved the anchor and adjustment problem for the tensioners, so they now operate correctly. I've ditched the LEDs too (for now).

I can lock-out the gear (manually locked in deployed position) and move on...

Everything will need dressing up a bit.

Time to work towards a controlled lift-off and touch-down cycle.