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Mike
03-29-2005, 06:08 PM
I'm looking for a quality microchip to work on some base-level programming. I want something with PWM outputs (3 is more than enough) and some digital/analog inputs (for things such as gyros and limit switches). I've checked the microchip.com site, but i'm not totally sure what i'm doing. Can anybody recommend a chip?

Matt Krass
03-29-2005, 06:27 PM
You might want to look in to the Atmel AVR series chips, I'm working with two right now, the AT90S8515 and the ATMEGA16L, the former has one pwm output and the latter four, along with an STK500 dev board. I have to warn you though, though I've successfully made a pwm pulse..I think...it won't control any servos I have...does anybody have an idea?

Joe Johnson
03-29-2005, 06:54 PM
I have been using the Motorola DSP 5680X series a lot lately. I love them.

Motorola calls them Hybrid DSPs. Basically, they are screamer number crunchers with enough onboard peripherals that the core processor is free to do pretty whatever it wants to. They have onboard stuff to do PWM, Timers, Queued ADC, SPI stuff, CAN, Quadrature Decode, Serial Communications, etc. Very nice for robot controls.

I am using the boards from New Micros Inc (www.newmicros.com) Don't pay any attention to that Forth stuff.* Get CodeWarrior (free license for code up to 16K -- easily done with all the peripherals doing the heavy lifting) from MetroWerks (www.metrowerks.com) I can almost guarantee that you'll like it better than MPLAB. I know I do.

Anyway, back to the New Micros boards, I have always been happy with the quality of the stuff I buy from them. For what it's worth...

Joe J.

*Forth is a great language whose time has past. It is a very cool language with power galore but, seriously, the designers of the language bet the farm against RAM becoming essentially free... ...they lost the bet... ...Sorry die hard Forth fans, but I have to call 'em as I see 'em.

Learning Forth is a great way to learn about programming in general, but I can't recommend it for non-educational uses.

Mike Betts
03-29-2005, 06:58 PM
I'm looking for a quality microchip to work on some base-level programming. I want something with PWM outputs (3 is more than enough) and some digital/analog inputs (for things such as gyros and limit switches). I've checked the microchip.com site, but i'm not totally sure what i'm doing. Can anybody recommend a chip?
Mike,

I would start by watching "Introduction to the PIC18 High Pin-Count and High Density family of devices" at http://techtrain.microchip.com/webseminars/WebSemCListArch.aspx.

It gives a fairly good overview as to what the Microship part number means and a good introduction to the various chips in the PIC18 family. You will find that other families like the PIC16 will make more sense as well...

Regards,

Mike

Mike
03-29-2005, 07:06 PM
Are all these as easy to use as say, the FIRST RC?

EDIT: I'll read that article, thanks.

Gdeaver
03-29-2005, 07:34 PM
You might look at Kronos robotics. http://kronosrobotics.com/xcart/customer/home.php . The Dios is an 18 series chip similar to what's in the first controller. They offer several kits with different carrier boards. The programing language is free. It's much easier to get started with than the microchip environment. Check the web site out. There are allot of app notes to help you get started. It's a basic interpreter thats well implemented. You can use in line assembler if you really want to take control of the chip. There are functions included for I2c, spi, and Dallas 1 wire plus allot of other chips.
I've also used the Netmedia basicx24 with students. It uses an Atmel chip.
The students got up and going faster with the Kronos stuff. Forget the basic stamp. However you might look at their stamps in the class room. They're well done tutorials.

Mike
03-29-2005, 08:19 PM
I'm still really new to this, so bear with me here.

From what I understand, I need a chip and a carrier. Will a combination of this (http://kronosrobotics.com/xcart/customer/product.php?productid=16169) and this (http://kronosrobotics.com/xcart/customer/product.php?productid=16386&cat=300&page=1) work? How would I connect them? I don't see where the PWM ports are, do I need something else for them? Are there any other parts I need? The example code they gave, it was in assembly. Can I still use c?

Thanks in advance.

seanwitte
03-29-2005, 09:11 PM
The Xport from Charmed Labs looks pretty cool. Programmable in C or C++ but requires a Game Boy Advance.

Be careful about PWM outputs. In the context of a microcontroller its different than the outputs on the FRC. Unless there is an integrated motor controller or H-bridge you won't be able to directly drive a motor. Otherwise you would use the onboard PWM output to drive an external H-bridge. Far easier to get a robot controller with the motor controller integrated already.