Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!sdd.hp.com!zaphod.mps.ohio-state.edu!hobbes.physics.uiowa.edu!news.iastate.edu!IASTATE.EDU!rickmc From: rickmc@IASTATE.EDU (Mcintosh Ricky Joe S) Newsgroups: sci.electronics Subject: Re: cheap microcomputer chips for gadgets Keywords: CMOS microcomputer chips gadgets Message-ID: <1991Jun26.093920@IASTATE.EDU> Date: 26 Jun 91 14:39:20 GMT References: <7991@alvin.mcnc.org> Sender: news@news.iastate.edu (USENET News System) Reply-To: rickmc@IASTATE.EDU (Mcintosh Ricky Joe S) Organization: Iowa State University Lines: 59 In article <7991@alvin.mcnc.org>, canovai@mcnc.org (1993]) writes: > > I have several electronic gadgets which I have built using > hardwired logic. I am interested in redesigning them using > microcomputer chips in order to give them more functionality. > I used to work with the MCS-48/51 (Intel) series of microcomputer > chips (back several years ago) but have been out of touch with > the developments in this area since then (the MCS-51 was the > best thing going at that time). > > My question is; is there a better family of microcomputer > chips available today for small gadget applications? > > My primary concerns are: > > * Low power consumption (must be CMOS) - for solar cell power > * Low cost (>$10? each) - potential for mass production > * speed is least essential > > Of course I could (and will) do much researching of this > myself but I was hoping that someone, who has already evaluated > the now numerous options available today, could point me in the > right direction. > > Also, what is the least expensive way to program these chips > now? Are there inexpensive programing software and hardware > setups/kits for pc's? ...are there service companies which will > take your code and do EPROM programming for a reasonable cost? > > Any experienced help would be appreciated. I would go back to the mcs-51 family. The micros have been out for a while, but haven't lost their usefulness. Many manufacturers have made modified versions of the micros. Signetics is coming out with a 33 MHz version, so if speed was necesary here it is. Others have added A/D and D/A converters, PWM, and many other functions that now is on the newer 16 bit micros. You asked for cheap. The 8751 can purchase for less than $10 in qty of 100 or more. Also old 8051's can be bought with outdated masked rom. You just pull up a the EA* pin use external rom. The cost $3 in qty of 1. Dallas Semiconductors makes an 8051 (5000) that can have as much as 32K of ram with battery backup and clock calender on the same 40 pin dip. you program it with the serial port and partition the remaining ram as data space. Also this is treated as internal memory so speed is increased. they cost $48 in qty of 100, but think what it saves you in you pcb, ram ic and rom ic. Now you have the extra par. ports, speed and you can program them yourself if you wish to build a simple rs-232 port. You also ask about having your code put in rom. eprom programers that can program 16 eproms at once are only about $300. so if you're planning on doing a few 100 a month you'll find it's cheaper to do it your self. The cheapest way is to buy a very large qty and have the program masked into the ic the your talking $4-7 each including masking, but look out for the number you need to buy. There are companies that do nothing but program 8751's for people. I've seen people using the 68hc11 and similar, but they do not have anything that the 51 family does actually they have less because of all the improvements that have been made over the years. 8051's come in cmos and are cheap in this form because they have been out for several years. If you use the powerdown modes and your previous experience you'll have no trouble getting a reliable and low power consuming 8051 project working. Good Luck in you search. Rick.