Microcontrollers

[ManTin361]

Hi everyone,

I just wanted to know what flavors of microcontrollers everyone out there is using. I plan on using a PIC18F458 or something close. Whats everyone else using?

Matt

P.S. Has anyone used this before? Good or bad?

[AnthonyRC]

it will certainly work, but you'll need to avoid floating point operations (if using C). In addition, running things like Kalman filters on one of these would be very difficult, it just doesn't have the processing power.

[ManTin361]

I want to program in C and use MicroC/OS-II (A RTOS written by Jean Labrosse). Floating point math would be nice, but not necessary. Do you have a inexpensive microcontroller that will handle all of this? I will need something that’s easy to learn though. What about MC68HC11? I know assembly language for this, but have never programmed it in C.

Thanks!
Matt

[sesat]

AVR.


Ram.

[ALtitudeap]

i am using the Parallax Basic Stamp 2p with a uM-FPU coprocessor. it is seeming to do the trick nicely. although it programs in basic :)

[ALtitudeap]

sorry double post.

[UUV13]

I don't know about UAV work but I use a gumstix and robostix boad for my AUV. It has plenty of processing power. I have mine running as a nav, sonar, and control system with no problems. I do know of UAV projects using the same setup. Gumstix site has links to them.
Gumstix (http://www.gumstix.com)

[clolson]

I don't know about UAV work but I use a gumstix and robostix boad for my AUV. It has plenty of processing power. I have mine running as a nav, sonar, and control system with no problems. I do know of UAV projects using the same setup. Gumstix site has links to them.
Gumstix (http://www.gumstix.com)

I don't know a lot about gumstix stuff and I haven't been able to get much info about their robostix board from their web site. Can this be used to drive servos? Read receiver outputs? It seems like it could be a nice platform ...

[sesat]

I've heard that the noise from a Gumstix board inhibits proper GPS signal reception. Anyone with experience with this?


Ram

[JettPilot]

I have never heard that, but its possible. The soloution is easy though, just keep it away from the GPS... Just about anything can wipe out a GPS if its put right next to it, but a foot or two works wonders :)

Those Gumstix boards are really great, I would be using a Gumstix board if I knew how to program the darn thing :mad:

[ElectroLawndart]

Like Jett said. Seperate the GPS and the mC. If that doesn't solve the problem put some metal RF shielding around it.

I'm looking at the Gumstix too. Who has experience with this one. Is the learning curve steep?

Dart

[LukeZ]

Matt,

I started off looking into using PC104 and I even bought one for a hefty chunk of change, but so far I have not used it. It's heavier than micros and draws more power, not to mention it's larger. But I'm keeping it around because you just never know...

What I've been developing with since is a PIC 18F452, which is quite similar to what you mentioned. I'm using Microchip's C18 C compiler for it, which is free, and although I've written a few functions in Assembly I guess I just prefer the ability to write in C. So that's a nice thing about Microchip's 18 line.

For the record, I'm doing extensive floating point math on mine - but it's true, I'm running out of program memory quickly. My semi-intent at this point is to use several micros. The 18F452 I'm working on now reads altitude, airspeed, temperature, humidity, voltage, and current. I'm pretty close to being out of room on the thing, so I intend to finish it up and have it be its own component that can communicate through a standard serial interface. Then I can move on to the next component...

And for that next component I think I'll be using PIC 18F2620, and maybe even replace my 452 with it - it has twice the memory at only 28 pins (much smaller footprint), and really the limitation for me was the program space, not the number of i/o pins.


However, like the everyone else I am pretty interested in the Gumstix boards, but have found their website to be pretty lacking, especially given the price of their products. If I'm going to spend that much money I want to know a lot about what I'm getting - and they don't do much explaining.


Luke

[UUV13]

The gumstix is a full linux computer so you can simply write and run programs on it rather than having to reflash a controller. The robostix board can run servos. If you go to their support area there is a ton of documents and diagrams for it. If you don't know C or C++ and linux I would say find a programmer. I'm the hardware tech and my friend does the sofware work. As for the price, I have a 400mhz unit that acts as an INU using sensors when it can't get a GPS fix, monitors hardware and battery, and a lot of other functions. It is a full computer with plenty of memory 64mb SDRAM and up to 16mb of storage not counting the CF card. I will note that I'm using it for an AUV not a UAV so it has to process more complex sensor information (which we're considering adding another gumstix to handle) and do INU calculations since it doesn't always have GPS to figure out where it is. I haven't had any problem with GPS and the unit. It might be overkill for a hobby UAV.

[himszy]

Are this is where your hiding out UUV, :d . I use picaxe chips. And strongly recommend to people that use a Basic Stamp, as the programmming language is the same and it has more features.

[Tomapowa]

Definitely ditto on the "PICAXE"...
Check out:

http://www.diyrc.com/Picaxe.html


Are this is where your hiding out UUV, :d . I use picaxe chips. And strongly recommend to people that use a Basic Stamp, as the programmming language is the same and it has more features.