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Mworks
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 Posted: Wed Jul 05, 2006 8:31 am Post subject: What cpu/IC is best for this project ? |
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I'm fairly new at working with cpu's and interfacing them at the board level.
What I need is a way for a pc to control up to 128 seperate devices from usb,parallel,ethernet, the connection method from pc to the device handling the 128 devices is not important.
I want to be able to issue a simple on/off command from the pc to each device. Later I would like to expand to being able to maybe do three state or analog control for each device but for now 0 or 1 switching would be fine.
I want to keep this as cheap as possible as the end product is for people on very low incomes.
I have already managed to get all the inputs I needed with the use of old xbox controllers and the windows device driver that was written for them. |
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JAC
Joined: 24 Jul 2005
Posts: 3469
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| Posted: Wed Jul 05, 2006 9:06 am Post subject: |
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Well....... pc interfacing is one step beyond what I normally do. USB has limited range, so drag out that old workhorse the serial port and throw a little embedded control into the mix to make something really useful!
If I had to do what you are describing I would hook up a microcontroller, like a PIC, in each remote device. Assign each device a unique address and interface each device to the same bus. Then issue commands directly to the serial port on the pc.
- simple wiring
- simple pc software
- almost unlimited devices
- a little bit of remote intelligence is never a bad thing. It also allows devices to talk directly to each other.
- advanced control.. do lots of cool things! on/off is so 1980.
- .......
Sounds like a school project  |
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CPUShack
Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA
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JAC
Joined: 24 Jul 2005
Posts: 3469
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| Posted: Fri Jul 07, 2006 4:11 am Post subject: |
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| u gotta love the free dev tools from microchip though lots of people using them.. so lots of help 'out there'. Fantastic pic list - outstanding! I saved like YEARS of my life learning code techniques from the Assembly gurus. My hair is still receeding though. bugger. |
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Mworks
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| Posted: Fri Jul 07, 2006 9:54 am Post subject: Pics |
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I have decided to use the PIC
I had heard of the PIC but never read up on them.
I didn't realize they were so capable, especially for the price.
I downloaded the microchip ide software and was able to purchase 30 PIC16F505 chips from a friend for 10.00.
I already have a programmer, made by willem.
Thanks for the help ! |
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JAC
Joined: 24 Jul 2005
Posts: 3469
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| Posted: Fri Jul 07, 2006 10:14 am Post subject: Re: Pics |
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| Mworks wrote: | I have decided to use the PIC
I had heard of the PIC but never read up on them.
I didn't realize they were so capable, especially for the price.
I downloaded the microchip ide software and was able to purchase 30 PIC16F505 chips from a friend for 10.00.
I already have a programmer, made by willem.
Thanks for the help ! |
Yeah, they are cheap. The flash parts are outstanding and there is a great deal of choice! Oh, make sure you erase a flash part before writing to it, keep an eye on your stack level and dont exceed the I/O port limits.
MPLAB is very good, it may be a little bit daunting for the first time, but the learning curve is worth it. I have been using it for nearly 10 years now. It was very basic back then, now there are many features.
Check out www.piclist.org for a ton of free code. Try use it to develop / understand your own code rather than plug and pray. |
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