Let's Make Robots!

Beginner robot..suggestions please!! (Axon and VEX for the bot)

Hello

Im envisaging on building my first robot, so would greatly appreciate any advice.

About me > I've some basic programming skills through GW-Basic and QuickBASIC which i learnt nearly 10yrs back. I suck at C programming, and am not well versed with microcontrollers/electronics, although im sure i can learn (maybe not C!!). Mechanically, im sure i can conjure up something fairly decent, if not pathetic!

I've been doing some research over the past few weeks and this is my proposed list. Please note that i most likely will NOT have a chance to change/upgrade once i buy these (finance constrains), hence would like to get something i can reuse over and over and at the same time, not get stuck with something very simple. The initial goal is build an autonomous bot rather than R/C, then perhaps add vision etc.

the list >

1. For the base structure > VEX protobot ; base platform only with wheels & motors

2. AXON microcontroller

3. Ultrasonic sensors

4. Power supply

 

Have i missed out anything? I read that the AXON uses ATmega640 which offers much scope for further expansion, but would it be difficult for someone with minimal C programming skills? I've also read about the PICAXE 28X board listed on this site; would it be a better choice? Please suggest alternates for the list, if need be!!

 

Thanks in advance

Felix

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wow! Seems you've come a long way; the experience gained over using all those different types of mcu's must have given you quite an advantage!

I've been looking at sample arduino code; i reckon i must have been too harsh on it. I think for now, i'll base my project on the mega mcu and see how it goes from there.

Thanks for all the help :)

Robologist, point well noted. Thanks! In fact, i reckon now that VEX is indeed expensive after calculating shipping > 199$ + 151$ ... 350$!! I guess it would certainly make more sense to start with something that you can build on your own and then develope, coz it would definitely work out cheaper. I think i should research more on the art of construction and then decide on buying tools and materials.

Thanks again robologist and voodoobot for the info regarding the boards. I am currently looking into tutorials for arduino. It might click on my limited programming senses! Btw, i read on one of the boards that the mega lacks a shield? I read that this can be attached etc, but would this be something to consider? Just curious, although i know not when im gonna be using one.

Again, out of curiosity, could i ask what boards/controllers you have used and what you use now? How well have they served you? Did you feel the need to upgrade soon? Did they help you learn?

 Thanks for reading :)

 Felix

Boards n stuff.  I have a number of Basic Stamps, various configurations from homebrew to standard. They were great to start with, good walk through tutorials, but somewhat limited. I actually believe these to be more capable than what I've seen of the PICAxe, though that system is popular too. Basic Stamp seems twice the speed and supported but more expensive, PICAxe seems more configurable and cheap.

I've got a few AVRs, 2313, 8515, Butterfly, but had been set aside to work with another MCU system.

That other MCU system was IsoMax based DSP micros. This was a very competent state machine system based on Forth, very capable, fast, and a bit expensive.  Easily to develop in, if you can understand how Forth works. The furthest from other programming methods, but interactive, can change some things in the program while running. 

Also have an ARM7 system, but only done minor bits in it. Seems also fast and capable, more conventional programming.

And finally an Arduino, appears to be a great beginning system, faster than either Stamps and PICAxe, and somewhat community supported.

Many thanks for all the suggestions :)

To be honest guys, i REALLY suck in C; maybe because i dint do a good job of paying attention in such classes and as time went on, found it to be increasingly complex and difficult to understand. Hence I've been trying to avoid stuff that links itself with C. I know vast majority of those controllers use C, but I'd gladly consider other options if given a chance to do so!

And if im not mistaken, AXON and Arduino both need to be programmed in C, correct?

So, as robologist puts it, i reckon PICAXE is the direction where i should be looking, unless there are better alternatives to this IC.

May i ask if anyone can suggest a kit to build the base, other than VEX? The reason why i cant make my own structure is cause i have very limited access to tools. Agreed its the best way to learn, but like i to have something that i can redesign and modify easily for future projects. Initially i was thinking about the irobot Create, but then realised that it wouldnt be of much help when trying to build something structurally different.

Thanks again for taking time to read this and reply.

Felix

The arduino is programed in a language thats similar to c and java, only a lot easier to code with than both of those.

I would highly recommend looking at the  reference and tutorials before deciding to steer away from the Ardy.

It has a growing support base and many people have started using it on this forum. 

I would look at the resources for the picaxe as well just to get familiar with that language as well to see what  would fit you best.

 

Felix, you misunderstood me. I felt the PICAxe 28X was a limited controller, that would be in the "get stuck with something very simple" class you were trying to avoid.

 The AXON is more capable, as is the ArduinoMega, and the ArduinoMega has an incredible amount of supportto get you past what you think is a difficuloty with C. Essentially, if you can program BASIC, the same concepts apply to C, Pascal, Fortran, Java, or whatever other language.

On kits, started to look, at SuperDroid, Lynxmotion, and maybe the VEX wasn't so expensive. Just feels better to me to buy a few tools, to build the robots out of cheap materials with, rather than buying parts that have been pre-made. 

I feel that the Vex protobot kit is a bit overpriced for what it is, some structural components and wheels and 4 servos for $200.

The Axon is nice, has the convenience of power and ground next to each IO, but is also priced at $100 for a Mega640 board.

 

I'd suggest making your own structure, building from wood and plastic and found objects and aluminum, buying a servo when needed, or a gearmotor for whatever design you have in mind. If gearmotors, then adding h-bridges for running them with a micro. One of the best systems I've seen for adding wheels to a robot recently has been the Banebots setup.  There are other options too, for different types of wheels and motors.

I'd also suggest the Arduino Mega if you want a higher pin count micro, that uses a Mega1280 with more memory than the Axon, for $65. Arduinos have a large support base to help in programming. 

Ultrasonics are fine as are infrared and any other sensor that could be added.

In any case, vision is something that is added to PCs at the moment, or much faster microprocessors rather than microcontrollers. 

A PICAxe 28X1 or X2 gets you back into that limited area that you seem to be pushing away from.

If you want to get into something that may be a bit easier than c, but still give you quite a bit to play with(very flexible), I'd look into the arduino. It has plenty of flexability and at some point could always be reset to a factory avr state for plain C programming. I can't say I'd recommend a pic/assembler approach as it might give you headaches from the possible high learning curve. If you want the challenge, go for it, they are great procs and very powerful when programmed in asm(though they can also be programmed in c). If you want simple and fairly flexible, the picaxe is a great choice(and a favorite of the board as well as myself).