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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The Tiny chips support pin change interrupts on all pins. You surely do not need two chips.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I would definitely get rid of the 1 second timeout. I use the interrupt to be sure that I do not<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>miss a pulse on a pin. If the pulses are long enough, then you can just poll and not worry about<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>using interrupts.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Here are fragments of code from my rain gauge that sleeps most of the time. It wakes up<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>on the rain sensor changing state or on a button press. If you want more details, let me know.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>---> Paul<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#if defined(__AVR_ATtiny84__)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#include <avr/interrupt.h><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#endif<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>const uint8_t SW_PIN = 4;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>const uint8_t RAIN_PIN = 8; // PCINT0<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>volatile uint8_t rain_pin_state = LOW;// does not matter what it is initialized to<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>volatile uint8_t rain_count = 0;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#if defined(__AVR_ATtiny84__)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>// PA4 handler<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>ISR(PCINT0_vect) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> // just wake up<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>// PB2 handler<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>ISR(PCINT1_vect) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> // see if the rain gauge has tipped<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> uint8_t save_rain_pin_state = rain_pin_state;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> if (save_rain_pin_state != (rain_pin_state = digitalRead(RAIN_PIN)))<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> rain_count++;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#endif<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#ifndef cbi<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#endif<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#ifndef sbi<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#endif<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>setup()<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>{<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> pinMode(RAIN_PIN, INPUT_PULLUP);<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> rain_pin_state = digitalRead(RAIN_PIN);<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>…<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#if defined(__AVR_ATtiny84__)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> sei(); // Turn on interrupts<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> // Pin interrupt setup for rain bucket<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> sbi(GIMSK,5); // Enable pin change interrupt 1<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> sbi(PCMSK1,2); // Allow pin changes on PB2<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>#endif<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>…<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>void loop()<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>{<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> // we expect rain_count to be 0 or 1. If it is more than 1, then it is likely a signal bounce<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> if (rain_count) {<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> …<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> }<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> TriEmbed [mailto:triembed-bounces@triembed.org] <b>On Behalf Of </b>Joe Fair<br><b>Sent:</b> Thursday, July 31, 2014 7:15 PM<br><b>To:</b> Jon Wolfe<br><b>Cc:</b> triembed@triembed.org<br><b>Subject:</b> Re: [TriEmbed] IR sensor vs trigger<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p>I think you are right, they kind of each need a chip. I was hoping to be smart enough to not to need more hardware. <br>Does the tiny sport two interrupts? Or maybe i can tie them together?<o:p></o:p></p><p>I guess i need to learn more about days sheets, too.<br>Joe<o:p></o:p></p><div><p class=MsoNormal>On Jul 30, 2014 10:09 PM, "Jon Wolfe" <<a href="mailto:jonjwolfe@yahoo.com">jonjwolfe@yahoo.com</a>> wrote:<o:p></o:p></p><div><div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>I agree with the others, it sounds like the trigger should get the interrupt.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>Like Jeff said, you want your interrupt to execute in as short of a time as possible. One approach might be to just set a flag on trigger presses then process the action in the main loop. That could still leave you with 1 sec latency if you are detecting IR hits, which would probably be pretty noticeable.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>I have never tried this on a tiny, but I'm making it a personal mission to find a use case for it, but you could use an RTOS, like <a href="http://www.femtoos.org/" target="_blank">http://www.femtoos.org/</a> Looks promising. I've used ChibiOS on Cortex M3/4's and found it pretty nice to work with, YMMV. <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>The other alternative approaches might be to try to reduce the 1 second detection loop. Or, to try to architect your own "cooperative multitasking" or coroutines. In short, write your detect loop so that instead of looping for 1 second, it just does a little bit of work and returns to the main loop, remembering where is was in the loop between each call. I use this approach a lot.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>I will say that you should try to handle debouncing the trigger in hardware as much as you can. I've tried software debouncing mechanical encoders in interrupt driven routines, and I can attest that it is maddening.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'>Lastly, you *could* always just buy a separate tiny for the detection, but I have no ulterior motive or bias there ;)<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p></div><div><div><div><div class=MsoNormal align=center style='text-align:center;background:white'><span style='font-family:"Helvetica","sans-serif";color:black'><hr size=1 width="100%" align=center></span></div><p class=MsoNormal style='background:white'><b><span style='font-family:"Arial","sans-serif";color:black'>From:</span></b><span style='font-family:"Arial","sans-serif";color:black'> Joe Fair <<a href="mailto:joe@fairanswers.com" target="_blank">joe@fairanswers.com</a>><br><b>To:</b> <a href="mailto:triembed@triembed.org" target="_blank">triembed@triembed.org</a> <br><b>Sent:</b> Saturday, July 26, 2014 4:09 PM<br><b>Subject:</b> [TriEmbed] IR sensor vs trigger</span><span style='font-family:"Helvetica","sans-serif";color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'><o:p> </o:p></span></p><div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Ok. I'm pretty close on getting my home made laser tag with at tiny 85s going, but now i have a question about design.<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>The loop I'm using detects a trigger pull, then a hit on the sensors. however, The pulse in function I'm using to sense IR ha a timeout of 1 second. If there is no inbound signal it is only checking got a trigger pull once a second.<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>So i need to use an interrupt, but does it matter if i use one on the trigger pull or the ir sensor? <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Helvetica","sans-serif";color:black'>Joe<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'><span style='font-family:"Helvetica","sans-serif";color:black'><br>_______________________________________________<br>Triangle, NC Embedded Computing mailing list<br><a href="mailto:TriEmbed@triembed.org" target="_blank">TriEmbed@triembed.org</a><br><a href="http://mail.triembed.org/mailman/listinfo/triembed_triembed.org" target="_blank">http://mail.triembed.org/mailman/listinfo/triembed_triembed.org</a><br>TriEmbed web site: <a href="http://triembed.org/" target="_blank">http://TriEmbed.org</a><br><br><o:p></o:p></span></p></div></div></div></div></div></div></div></body></html>