Reading an ADC channel is dead simple and works first time. Cool. Outputting a servo signal should be just as easy. It isn't. I check the code (C++ is still alien to me) and libraries, jump through some hoops and then it compiles. Checking the signal on the scope shows it's not moving and this highlights the major drawback of the mBed: no debug.
Ducted Fan VTOL UAV / Sci-Fi Craft
This blog follows progress on a small scratch-built VTOL platform. Sci-Fi styling and modeling are just as important to me as functional operation, even if it compromises the design. I'm doing this because (while) I feel like it, no other reason. See first post (intro) for more...
Wednesday, 15 June 2011
Why are simple things so difficult?
Reading an ADC channel is dead simple and works first time. Cool. Outputting a servo signal should be just as easy. It isn't. I check the code (C++ is still alien to me) and libraries, jump through some hoops and then it compiles. Checking the signal on the scope shows it's not moving and this highlights the major drawback of the mBed: no debug.
Thursday, 10 February 2011
The path of least resistance
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.
Sunday, 16 January 2011
Happy bunny
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?)
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?
Friday, 14 January 2011
ICD2 is OK
Is it a Win7 problem?
Still no luck
I'm going to take the ICD2 to work today and try it on my machine there.
Wednesday, 12 January 2011
Been too long!
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...