Hey guys,

  Got to bring down the price on a project I've been contracted for. I really want to stick with a micro-controller do to it's multi-functionality. I'm using the standard PIC16f84 right now. I noticed Zilog has a Z8 processor which fits many of the applications I need it for, but if there is say a 4 bit micro-controller I'm not aware of? or anything dirt cheap, please I'd like to know.

                                                              Thanks  8)
Posted on 2006-07-16 09:36:41 by mrgone
Since you're familiar with Microchip products and a low end 8-bit PIC costs 39cents, I'd stick with the PIC.


Posted on 2006-07-22 17:33:22 by pdixon
?  ? Hey thanks for link. I was looking for their line card. That 39 center doesn't have interrupts and I need atleast two, the timer and one hardware. I need to fish through those PDFs. Thanks to you I got them all on one page! :) Do you know anything about Motorola 68HC11 family pricing?
Posted on 2006-07-24 10:11:19 by mrgone
Sorry, I know nothing about other families. I only use PICs.

Posted on 2006-07-24 11:39:29 by pdixon
  Well I'll give you the answer that my research showed. The Motorola 68hc11 family is only made by Freescale now and it looks like the prices start from 3 dollars. Yeah Paul it looks like you just gave me my next work assignment...lol. The boss man loves the idea of 39 cents which is the very cheapest I could find. I told him I needed interrupts but he wants a work around. Do you know what kind of programmer I need?
Posted on 2006-07-31 09:49:36 by mrgone
I haven't used that particular chip before but I think most of the modern Flash PICs can be programmed with the cheap PIC Kit-2 programmer:

Mine cost about 27 (50USD) from Microchip.

Posted on 2006-07-31 17:33:50 by pdixon
  Thanks, That's what Microchip told me too. Only 50 bucks? Too cool. I noticed PIC16f84 wasn't listed as one of it's capabilities. So have you programmed with the PIC10F2x devices? I noticed there are no interrupts. How does that internal timer work? Is it crystal controlled? I'm gonna try polling on a condition that needs some what a degree of timing accuracy. Haven't made any promisses yet..lol. Wouldn't you say the price rivals that of programmable logic devices? I need the flexibility of a processor. You know your a hero when you can add new features just by programming... :lol:
Posted on 2006-08-01 19:22:15 by mrgone
For most logic devices I use an expensive general purpose programmer.
I've only programmed 3 PIC types using the PICKit-2, 16F690 (suplied as a sample with the board) the PIC18F2550 and 18F4550 which are not listed in the compatible devices.
Most modern FLASH PICs have In Circuit Serial Programming which allows the chip to be programmed via 5 pins even after it's been assembled in a circuit. The devices compatible with the PICKit-2 are all of a similar pin layout so you can just remove the sample device from its socket and plug in your target device to program it.
For devices not on the list all I did was to remove the sample chip from its socket, solder a suitable socket for my target device into the patchboard on the lower half of the demo board supplied and take the 5 connections needed for programming from the sample chip socket to my target socket. It works fine with the 2 unlisted PICs I've tried.

The 10F2xx devices have an internal 4MHz oscillator which can be tweaked to within 1% of 4MHz. If you want more accuracy for your timer you need to provide and external Xtal oscilator but that'll use up one of you I/O pins and you only have 4 to start with.

No interrupts means you have to poll the timer to see what it's count is.
If you need interrupts then use a more complex device. You can get interrupts and a lot more for under $1.
Full data sheets for all of these PICs can be downloaded from Microchip.

Posted on 2006-08-02 06:49:56 by pdixon
OK, my PicKit2 has no problem with the 16F690 but I have hooked up a cable to the output connector so I can try to program a 10F206 chip. I get the "VDD error" and I scoped it out and it looks like all the signals are being loaded down. I have checked and re-checked the connections and according to the PicKit2 manual & the 10F2xx user's guide it is all correct. So I ordered a whole tube of 10F2xx chips & have same problem. I also have two "Low pin count Demo boards" and they both do the same thing. If I put the sample 16F690 back in it works fine.

Here are my connections:

(output conn)

Posted on 2006-11-10 14:04:08 by mrgone
I had a similar vdd error with my pickit2 doing some 12f629 chips.  I contacted Microchip and they had me send in the pickit and sent me a new one which doesn't have the problem.
Posted on 2006-11-10 20:25:02 by JimG
  Hey thanks, Your much quicker than they are  :lol: .  Well did yours work with the sample chip they gave you? Might works fine with the sample 16F690.
Posted on 2006-11-11 15:37:25 by mrgone
To tell the truth, I was so focused on getting the 8pin chips working that I don't remember trying to reprogram the 690 before sorting out the problem.

Are you aware of http://www.electro-tech-online.com/micro-controllers/?  Great people over there.
Posted on 2006-11-11 21:11:26 by JimG
  Thanks again! Looks good, I put it in favorites. Microchip wants me to call them Monday morning since they couldn't answer me in forum or on webticket.
Posted on 2006-11-12 13:13:11 by mrgone