Brian: A 28 pin chip is much wider than a fourteen pin chip, so unless you want to split the socket and spread them out, two 14pin sockets will not equal one 28pin socket. Mark AVR-Chat@yahoogroups.com wrote: There are 13 messages in this issue. Topics in this digest: 1. Re: Digest Number 574 From: Mark Weston 2. AVR Forums From: "fnatmed" 3. Re: AVR Tachometer From: "fnatmed" 4. Re: AVR Tachometer From: "fnatmed" 5. Re: Where to buy IC socket for Mega 8? From: "Greg Koss" 6. Checking individual Pin in PORTD!!! From: "Steven Chang-Lin Yu" 7. Re: AVR Tachometer From: "William Nachefski" 8. testing From: "mes Springnet, Chatham" 9. PIC18 Microchip group ? From: "mes Springnet, Chatham" 10. RE: AVR Tachometer From: "Larry Barello" 11. Re: PIC18 Microchip group ? From: David VanHorn 12. Re: Re: AVR Tachometer From: Snowden 13. Re: Re: AVR Tachometer From: Bernd Felsche ________________________________________________________________________ ________________________________________________________________________ Message: 1 Date: Wed, 31 Dec 2003 05:34:09 -0800 (PST) From: Mark Weston Subject: Re: Digest Number 574 I'm pretty sure you'll find an article and schematics for a tachometer in December's issue of Circuit Cellar. And it even uses an Atmel Mega8. Mark Oh, and Brian, good one about doubling up the 14 pin sockets!! AVR-Chat@yahoogroups.com wrote: There are 16 messages in this issue. Topics in this digest: 1. RE: Where to buy IC socket for Mega 8? From: "Brian Fairchild" 2. Re: M128 ADC problem From: John Samperi 3. RE: Where to buy IC socket for Mega 8? From: John Samperi 4. Re: M128 ADC problem From: David VanHorn 5. RE: M128 ADC problem From: "Larry Barello" 6. Re: M128 ADC problem From: David VanHorn 7. RE: M128 ADC problem From: David VanHorn 8. Stk 500 From: "Capricon" 9. Re: Stk 500 From: David VanHorn 10. AVR Tachometer From: "William Nachefski" 11. Re: AVR Tachometer From: "Jesper Hansen" 12. Re: M128 ADC problem From: John Samperi 13. RE: AVR Tachometer From: "Al Welch" 14. Re: AVR Tachometer From: "William Nachefski" 15. Re: AVR Tachometer From: Bernd Felsche 16. Re: AVR Tachometer From: "William Nachefski" ________________________________________________________________________ ________________________________________________________________________ Message: 1 Date: Tue, 30 Dec 2003 08:42:15 -0000 From: "Brian Fairchild" Subject: RE: Where to buy IC socket for Mega 8? What not just use 2 x 14pin dip sockets end-to-end? Brian -----Original Message----- From: c45a6 [mailto:clone45@hotmail.com] Sent: 29 December 2003 19:06 To: AVR-Chat@yahoogroups.com Subject: [AVR-Chat] Where to buy IC socket for Mega 8? Hello! Does anyone have a source for buying IC sockets for the Atmel Mega 8 (DIP package)? I can't seem to find them in the Digikey catalogue, but I know they must be abundant. Thanks! - Bret To unsubscribe from this group, send an email to: AVR-Chat-unsubscribe@yahoogroups.com Yahoo! Groups Sponsor ADVERTISEMENT roupweb/S=1706554205:HM/EXP=1072811143/A=1911858/R=0/*http://www.lifesca peinc.com/picasa/landing.php?capid=222&caId=1987> click here pmail/S=:HM/A=1911858/rand=424617461> _____ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/AVR-Chat/ * To unsubscribe from this group, send an email to: AVR-Chat-unsubscribe@yahoogroups.com * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service . [This message contained attachments] ________________________________________________________________________ ________________________________________________________________________ Message: 2 Date: Tue, 30 Dec 2003 20:44:46 +1100 From: John Samperi Subject: Re: M128 ADC problem At 12:29 AM 30/12/03 -0500, you wrote: > > IN TEMP,ADCH ;GET 8 BIT RESULT > >I always get to this point, indicating that I am indeed talking to >the ADC, since the conversion complete bit does clear. >At this point, I only ever get 0x00 in ACCUM. David, ADCH only has the top 2 bits IIRC (bit 8 &9), so reading a value which is less than 256 would give you 00 as above in ADCH. I think I read ADCL and ADCH and rotate the value left twice to get an 8 bit value in one of the applications with the 8535. Regards John Samperi ****************************************************** Ampertronics Pty. Ltd. 11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA Tel. (02) 9674-6495 Fax (02) 9674-8745 Email: samperi@ampertronics.com.au Website http://ampertronics.com.au * Electronic Design * Technical Services * Contract Assembly ****************************************************** ________________________________________________________________________ ________________________________________________________________________ Message: 3 Date: Tue, 30 Dec 2003 20:46:22 +1100 From: John Samperi Subject: RE: Where to buy IC socket for Mega 8? At 08:42 AM 30/12/03 -0000, you wrote: > What not just use 2 x 14pin dip sockets end-to-end? Brian I use 2xSIP socket strips, but if you can get the sockets it's a bit easier. Regards John Samperi ****************************************************** Ampertronics Pty. Ltd. 11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA Tel. (02) 9674-6495 Fax (02) 9674-8745 Email: samperi@ampertronics.com.au Website http://ampertronics.com.au * Electronic Design * Technical Services * Contract Assembly ****************************************************** ________________________________________________________________________ ________________________________________________________________________ Message: 4 Date: Tue, 30 Dec 2003 10:02:28 -0500 From: David VanHorn Subject: Re: M128 ADC problem At 08:44 PM 12/30/2003 +1100, John Samperi wrote: >At 12:29 AM 30/12/03 -0500, you wrote: >> >> IN TEMP,ADCH ;GET 8 BIT RESULT >> >>I always get to this point, indicating that I am indeed talking to >>the ADC, since the conversion complete bit does clear. >>At this point, I only ever get 0x00 in ACCUM. > >David, ADCH only has the top 2 bits IIRC (bit 8 &9), >so reading a value which is less than 256 would give you >00 as above in ADCH. I think I read ADCL and ADCH >and rotate the value left twice to get an 8 bit value in one >of the applications with the 8535. I'm setting for left-justified, so the result should be 8 bit, and all in ADCH. ________________________________________________________________________ ________________________________________________________________________ Message: 5 Date: Tue, 30 Dec 2003 08:46:34 -0800 From: "Larry Barello" Subject: RE: M128 ADC problem I don't see anything wrong with the code, but the documentation is off. Just a couple notes: you can enable, set the clock and start the first conversion in one write. There is no need to delay 15us, etc. Just let er rip and discard the first conversion - unless that delay you have is to allow the Aref cap to charge... In any case the first, dummy conversion is something like 24 cycles long and at 2mhz clock (your doco says 125khz, but your code selects 2mhz) that should be sufficient. As to the problem? Well, is ADCH declared correctly in the header? I use the left adjusted, high speed clock ADC on an mega16 and it works like a champ. Since you said the normal ADC routines work, I am assuming the Aref pin is good and not tied to +5v or something like that. ________________________________________________________________________ ________________________________________________________________________ Message: 6 Date: Tue, 30 Dec 2003 11:13:42 -0500 From: David VanHorn Subject: Re: M128 ADC problem Nevermind. :) The code is good. No voltage to measure. :-P ________________________________________________________________________ ________________________________________________________________________ Message: 7 Date: Tue, 30 Dec 2003 12:04:44 -0500 From: David VanHorn Subject: RE: M128 ADC problem At 08:46 AM 12/30/2003 -0800, Larry Barello wrote: >I don't see anything wrong with the code, but the documentation is off. > >Just a couple notes: you can enable, set the clock and start the first >conversion in one write. There is no need to delay 15us, etc. Yeah, that was just "bulletproofing". > Just let er >rip and discard the first conversion - unless that delay you have is to >allow the Aref cap to charge... No, I saw a note about not enabling until one ADC clock after the ref/mux switch. A foof-loop is about twice that. > In any case the first, dummy conversion is >something like 24 cycles long and at 2mhz clock (your doco says 125khz, but >your code selects 2mhz) that should be sufficient. AH! You got me :) Three bits does not equal 3. :-P 87! >As to the problem? Well, is ADCH declared correctly in the header? I use >the left adjusted, high speed clock ADC on an mega16 and it works like a >champ. Since you said the normal ADC routines work, I am assuming the Aref >pin is good and not tied to +5v or something like that. It was simpler than that, the voltage that I was trying to measure wasn't turned on yet... 0V.. @#%@^ ________________________________________________________________________ ________________________________________________________________________ Message: 8 Date: Tue, 30 Dec 2003 10:23:07 -0800 From: "Capricon" Subject: Stk 500 Hi, I have bought a stk 500. Do I need to buy the avr programmer seperate? Capri [This message contained attachments] ________________________________________________________________________ ________________________________________________________________________ Message: 9 Date: Tue, 30 Dec 2003 13:36:02 -0500 From: David VanHorn Subject: Re: Stk 500 At 10:23 AM 12/30/2003 -0800, Capricon wrote: >Hi, > >I have bought a stk 500. Do I need to buy the avr programmer seperate? No, it is one. ________________________________________________________________________ ________________________________________________________________________ Message: 10 Date: Tue, 30 Dec 2003 20:18:21 -0000 From: "William Nachefski" Subject: AVR Tachometer Hello All! I am just getting started into AVR's. I am seeking help on a circuit. I need to build a tachometer with opitcal pick up. The max RPM to be counted will be around 200,000 RPM. I was told that pretty much all of the tasks could be handled in code with a microcontroller. My pickup is a Phototransistor/LED its set up to give one pulse per revolution. So basically all I need is a frequency counter with a 1 sec gate time, and then multiply the value by 60,(my guess)Then to display the data on a 6 digit LED display. I don't know really anything about M.C's but bought a few 28 pin Mega8 chips to experiment with. What should the circuit look like? I am thinking the only thing I need on the board would be the display + multiplexing components and the Mega8 with a connector runing from a input pin(interupt pin?)Let me know if I am on the right track. Or if someone else has built one of these. Any help would be greatly appreciated! Thanks Happy Holidays William Nachefski ________________________________________________________________________ ________________________________________________________________________ Message: 11 Date: Tue, 30 Dec 2003 21:26:05 +0100 From: "Jesper Hansen" Subject: Re: AVR Tachometer > I am just getting started into AVR's. I am seeking help on a > circuit. I need to build a tachometer with opitcal pick up. The max > RPM to be counted will be around 200,000 RPM. Hmmm. Playing with model jet engines ? ;-) /Jesper www.yampp.com ________________________________________________________________________ ________________________________________________________________________ Message: 12 Date: Wed, 31 Dec 2003 08:13:56 +1100 From: John Samperi Subject: Re: M128 ADC problem At 10:02 AM 30/12/03 -0500, you wrote: >>and rotate the value left twice to get an 8 bit value in one >>of the applications with the 8535. Of course that would be rotate right in the northern hemisphere :-) >I'm setting for left-justified, so the result should be 8 bit, and all in ADCH. > Nifty feature. It was not present in the 8535, so I learned something new! Regards John Samperi ****************************************************** Ampertronics Pty. Ltd. 11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA Tel. (02) 9674-6495 Fax (02) 9674-8745 Email: samperi@ampertronics.com.au Website http://ampertronics.com.au * Electronic Design * Technical Services * Contract Assembly ****************************************************** ________________________________________________________________________ ________________________________________________________________________ Message: 13 Date: Tue, 30 Dec 2003 13:29:38 -0800 From: "Al Welch" Subject: RE: AVR Tachometer William, Perhaps you may want to run your phototransistor output through a schmitt trigger such as an 74ls14 chip which will make the pulses cleanly toggle between digital one and zero. Otherwise there could be a slow rise and fall shape to the output which could confuse your counting. Seems like you could then use an external interrupt input to interrupt when the input pulses, add one each time. Then setup a timer to provide your one second window. The display could run in the foreground to post answers from the timer. Al Welch -----Original Message----- From: William Nachefski [mailto:slaphappysamy@yahoo.com] Sent: Tuesday, December 30, 2003 12:18 PM To: AVR-Chat@yahoogroups.com Subject: [AVR-Chat] AVR Tachometer Hello All! I am just getting started into AVR's. I am seeking help on a circuit. I need to build a tachometer with opitcal pick up. The max RPM to be counted will be around 200,000 RPM. I was told that pretty much all of the tasks could be handled in code with a microcontroller. My pickup is a Phototransistor/LED its set up to give one pulse per revolution. So basically all I need is a frequency counter with a 1 sec gate time, and then multiply the value by 60,(my guess)Then to display the data on a 6 digit LED display. I don't know really anything about M.C's but bought a few 28 pin Mega8 chips to experiment with. What should the circuit look like? I am thinking the only thing I need on the board would be the display + multiplexing components and the Mega8 with a connector runing from a input pin(interupt pin?)Let me know if I am on the right track. Or if someone else has built one of these. Any help would be greatly appreciated! Thanks Happy Holidays William Nachefski Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/AVR-Chat/ To unsubscribe from this group, send an email to: AVR-Chat-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ ________________________________________________________________________ ________________________________________________________________________ Message: 14 Date: Tue, 30 Dec 2003 22:57:39 -0000 From: "William Nachefski" Subject: Re: AVR Tachometer --- I guess the 200,000 rpm gave me away. Yes this is for a jet engine, but not a model. Its a rather large homegrown one. In AVR-Chat@yahoogroups.com, "Jesper Hansen" wrote: > > I am just getting started into AVR's. I am seeking help on a > > circuit. I need to build a tachometer with opitcal pick up. The max > > RPM to be counted will be around 200,000 RPM. > > Hmmm. Playing with model jet engines ? ;-) > > > /Jesper > www.yampp.com ________________________________________________________________________ ________________________________________________________________________ Message: 15 Date: Wed, 31 Dec 2003 08:54:47 +0800 From: Bernd Felsche Subject: Re: AVR Tachometer On Tue, Dec 30, 2003 at 08:18:21PM -0000, William Nachefski wrote: > I am just getting started into AVR's. I am seeking help on a > circuit. I need to build a tachometer with opitcal pick up. The max > RPM to be counted will be around 200,000 RPM. I was told that pretty > much all of the tasks could be handled in code with a > microcontroller. My pickup is a Phototransistor/LED its set up to > give one pulse per revolution. So basically all I need is a > frequency counter with a 1 sec gate time, and then multiply the value > by 60,(my guess)Then to display the data on a 6 digit LED display. By that do you mean you want 1ppm resolution? That's a tough task. And you won't get it by multiplying a simple count by 60. You'd have to count at least 60 pulses per rev. > I don't know really anything about M.C's but bought a few 28 pin > Mega8 chips to experiment with. What should the circuit look like? Schmitt trigger to "square-up" the signal, feeding to an interrupt pin. LED display is probably easiest, given the number of required digits. You can MUX and drive the digits from the Mega8; unless the display is huge. Depending on the accuracy and range of speeds you really need, you could measure the period between pulses and invert. Display the result, reset counter and start counting on the next pulse; stop when the next pulse arrives. etc. Because one pulse per rev results in timing of much less than a millisecond, you'll probably want to average over a set of results spanning at least a tenth of a second. (Moving average.) If the machine stops spinning faster than that, you have a bigger problem than speed measurement anyway. > I am thinking the only thing I need on the board would be the display > + multiplexing components and the Mega8 with a connector runing from > a input pin(interupt pin?)Let me know if I am on the right track. Or > if someone else has built one of these. Any help would be greatly > appreciated! -- /"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia \ / ASCII ribbon campaign | I'm a .signature virus! X against HTML mail | Copy me into your ~/.signature / \ and postings | to help me spread! ________________________________________________________________________ ________________________________________________________________________ Message: 16 Date: Wed, 31 Dec 2003 02:09:25 -0000 From: "William Nachefski" Subject: Re: AVR Tachometer I Need a pretty broad range, from say 15,000 rpm to 200,000. Accuracy doesn't have to be that percise as long as its within a couple of thousand actuall rpms. What I meant was With each complete rotation of the turbine rotar shaft I get one pulse from the Phototransistor. So that equates to one pulse to the M.C. per revolution. Thanks for the help guys keep the suggestions comming! William --- In AVR-Chat@yahoogroups.com, Bernd Felsche wrote: > On Tue, Dec 30, 2003 at 08:18:21PM -0000, William Nachefski wrote: > > > I am just getting started into AVR's. I am seeking help on a > > circuit. I need to build a tachometer with opitcal pick up. The max > > RPM to be counted will be around 200,000 RPM. I was told that pretty > > much all of the tasks could be handled in code with a > > microcontroller. My pickup is a Phototransistor/LED its set up to > > give one pulse per revolution. So basically all I need is a > > frequency counter with a 1 sec gate time, and then multiply the value > > by 60,(my guess)Then to display the data on a 6 digit LED display. > > By that do you mean you want 1ppm resolution? > > That's a tough task. And you won't get it by multiplying a simple > count by 60. You'd have to count at least 60 pulses per rev. > > > I don't know really anything about M.C's but bought a few 28 pin > > Mega8 chips to experiment with. What should the circuit look like? > > Schmitt trigger to "square-up" the signal, feeding to an interrupt > pin. LED display is probably easiest, given the number of required > digits. You can MUX and drive the digits from the Mega8; unless the > display is huge. > > Depending on the accuracy and range of speeds you really need, you > could measure the period between pulses and invert. Display the === message truncated === --------------------------------- Do you Yahoo!? Find out what made the Top Yahoo! Searches of 2003 === message truncated === --------------------------------- Do you Yahoo!? Find out what made the Top Yahoo! Searches of 2003
Message
Re: [AVR-Chat] Digest Number 575
2004-01-02 by Mark Weston