Post by thread:[PIC]: Waking from sleep on ADC change?

Hi, this is my first post to the list so I hope it's going to the right place/formatted correctly :-) I'm working on a (commercial) project that involves a 16C73, most of the other circuit functions are done but I still need to read ADC channel one (RA0), process the value and create a signal that gets sent to a piezo sounder. The ADC is my main problem, I have it reading values, thanks to the Piclist FAQ, but I need the PIC to sleep for as much of the time as possible, it's currently sleeping while it converts then it wakes up and I send its value to the piezo code, but I need then to put it back into sleep and wait until ADC channel one or RA1 changes (circuit power use is critical). I think I can work out how to wake from sleep on RA1 changing, but I don't even think it's possible to wake from sleep on a change in the analog input? And, as a side note, does anyone know anything about piezo sounders? On the sig-gen it's frequency response can only be described as pathetic, and it appears (annoyingly) to have a sweet spot at 3KHz, the customer wants a 'Tone' control and as I can't just vary the frequency like I was hoping to do I'm a bit at a loss. I think something along the lines of a complex waveform with the ADC value being used to vary the harmonics would be the way forward, has anyone done this before? Many thanks to anyone who can suggest anything, Jonathan Starr R&D Technician Electronix Limited Tel +44 (0)1993 700510 Fax +44 (0)1993 700511 e-mail spam_OUTjonathansTakeThisOuTelectronix.co.uk web http://www.electronix.co.uk This e-mail has been sent to you by Electronix Ltd. This communication is intended for the addressee only, is private and confidential, and is subject to the applicable terms and conditions. If you are not the intended recipient, any disclosure, copying or distribution of this information is strictly prohibited. -- http://www.piclist.com hint: To leave the PICList .....piclist-unsubscribe-requestKILLspam@spam@mitvma.mit.edu

{Quote hidden}> -----Original Message----- > From: Jonathan Starr [SMTP:JonathanSKILLspamELECTRONIX.CO.UK] > Sent: Monday, June 10, 2002 10:23 AM > To: .....PICLISTKILLspam.....MITVMA.MIT.EDU > Subject: [PIC]: Waking from sleep on ADC change? > > Hi, this is my first post to the list so I hope it's going to the right > place/formatted correctly :-) > > I'm working on a (commercial) project that involves a 16C73, most of the > other circuit functions are done but I still need to read ADC channel one > (RA0), process the value and create a signal that gets sent to a piezo > sounder. > The ADC is my main problem, I have it reading values, thanks to the > Piclist FAQ, but I need the PIC to sleep for as much of the time as > possible, it's currently sleeping while it converts then it wakes up and I > send its value to the piezo code, but I need then to put it back into > sleep and wait until ADC channel one or RA1 changes (circuit power use is > critical). > I think I can work out how to wake from sleep on RA1 changing, but I don't > even think it's possible to wake from sleep on a change in the analog > input? > You have a problem in both cases. RA1 has no interrupt on change facility, unless this is a typo and you meant RB1? There is no way to wake up from a change in analog value as you suspected, the only wakeup ascociated with the A/D converter is the end of conversion interrupt. The ADC module itself raises power consumption, so depending on how often you need to sample, you might be better off using a timer interrupt to enable the ADC module and the ADC interrupt to disable the module, the aim being to keep the ADC module disabled for as much time as possible. The timer interrupt could be used to check pin RA1 as well (assuming it wasn't a typo). > And, as a side note, does anyone know anything about piezo sounders? > On the sig-gen it's frequency response can only be described as pathetic, > and it appears (annoyingly) to have a sweet spot at 3KHz, the customer > wants a 'Tone' control and as I can't just vary the frequency like I was > hoping to do I'm a bit at a loss. > I think something along the lines of a complex waveform with the ADC value > being used to vary the harmonics would be the way forward, has anyone done > this before? > Common, cheap piezo sounders have a natural resonant frequency as you have found, which is why they are generaly used for single tones, as warning buzzers etc. The resonant frequency and frequency response will be determined to a large extent on how the bare piezo disk is mounted. Obviously if you have a piezo that comes pre-mounted to a plastic casing your choices are limited. I don't think the complex waveform idea is going to help much either, the piezo will only respond to the frequencies around it's resonant point, irrespective if those frequencies are a fundamental or a harmonic of the waveform you generated. You can obtain piezo's with quite a wide frequency response, designed to be used as replacements for small speakers in e.g. laptops. http://www.panasonic.com/industrial/components/pdf/card_speaker_dne.pdf is an example. I suspect they cost considerably more than the common devices used for warning beeps etc. If you could give an idea of the device being used I'm sure that you'd get some suggestions from the list for improved performance. Regards Mike -- http://www.piclist.com hint: To leave the PICList EraseMEpiclist-unsubscribe-requestspam_OUTTakeThisOuTmitvma.mit.edu

On Mon, 10 Jun 2002, Michael Rigby-Jones wrote: {Quote hidden}> > I'm working on a (commercial) project that involves a 16C73, most of the > > other circuit functions are done but I still need to read ADC channel one > > (RA0), process the value and create a signal that gets sent to a piezo > > sounder. > > The ADC is my main problem, I have it reading values, thanks to the > > Piclist FAQ, but I need the PIC to sleep for as much of the time as > > possible, it's currently sleeping while it converts then it wakes up and I > > send its value to the piezo code, but I need then to put it back into > > sleep and wait until ADC channel one or RA1 changes (circuit power use is > > critical). > > I think I can work out how to wake from sleep on RA1 changing, but I don't > > even think it's possible to wake from sleep on a change in the analog > > input? > > > You have a problem in both cases. RA1 has no interrupt on change facility, > unless this is a typo and you meant RB1? There is no way to wake up from a > change in analog value as you suspected, the only wakeup ascociated with the > A/D converter is the end of conversion interrupt. The ADC module itself > raises power consumption, so depending on how often you need to sample, you > might be better off using a timer interrupt to enable the ADC module and > the ADC interrupt to disable the module, the aim being to keep the ADC > module disabled for as much time as possible. The timer interrupt could be > used to check pin RA1 as well (assuming it wasn't a typo). > or to use interrupt on RB0 ( or any other interrupt on change) with a comparator. If the analog input exceed the reference then an interrupt will wake up the whole mess, perform the measurement and go back to sleep again after it finished. A time delay will be necessary from the wake up moment to measurement(s). Vasile -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Damn, I didn't think of the fact that it will use power even when the main core is asleep, that won't do. I have revised the design, it will only sample the ADC when it needs to alarm, as the ADC value only affects the alarm tone there is no point me ever doing otherwise...whoops. As for the wake-on-change I haven't ever used it before so I guess I did mean RB1 :-) Thank-you everybody for your help with that. I have got further with the piezo problem, for something with an appaling bandwidth it is suprisingly agile when it comes to making musical tones. Although there is something that somebody may be able to help me with, a long time ago I'm sure I read of someones efforts to reproduce sounds via the PIC using a large RAM table with wave data in it, if anybody thinks they know a link it would be greatly appriciated, as melodys are extreamly hard to code as consecutive delays. >>> Vasile Surducan <vasilespam_OUTS3.ITIM-CJ.RO> 11/06/2002 11:42:28 >>> On Mon, 10 Jun 2002, Michael Rigby-Jones wrote: {Quote hidden}> > I'm working on a (commercial) project that involves a 16C73, most of the > > other circuit functions are done but I still need to read ADC channel one > > (RA0), process the value and create a signal that gets sent to a piezo > > sounder. > > The ADC is my main problem, I have it reading values, thanks to the > > Piclist FAQ, but I need the PIC to sleep for as much of the time as > > possible, it's currently sleeping while it converts then it wakes up and I > > send its value to the piezo code, but I need then to put it back into > > sleep and wait until ADC channel one or RA1 changes (circuit power use is > > critical). > > I think I can work out how to wake from sleep on RA1 changing, but I don't > > even think it's possible to wake from sleep on a change in the analog > > input? > > > You have a problem in both cases. RA1 has no interrupt on change facility, > unless this is a typo and you meant RB1? There is no way to wake up from a > change in analog value as you suspected, the only wakeup ascociated with the > A/D converter is the end of conversion interrupt. The ADC module itself > raises power consumption, so depending on how often you need to sample, you > might be better off using a timer interrupt to enable the ADC module and > the ADC interrupt to disable the module, the aim being to keep the ADC > module disabled for as much time as possible. The timer interrupt could be > used to check pin RA1 as well (assuming it wasn't a typo). > or to use interrupt on RB0 ( or any other interrupt on change) with a comparator. If the analog input exceed the reference then an interrupt will wake up the whole mess, perform the measurement and go back to sleep again after it finished. A time delay will be necessary from the wake up moment to measurement(s). Vasile -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

>> Although there is something that somebody may be able to help me with, a long time ago I'm sure I read of someones efforts to reproduce sounds via the PIC using a large RAM table with wave data in it, if anybody thinks they know a link it would be greatly appriciated, as melodys are extreamly hard to code as consecutive delays. << My HAL project produces audio from WAV data stored in program memory. See http://www.embedinc.com/pic/hal.htm. The details of fetching the WAV data, interpolating adjacent samples, and writing to the PWM output are in the HAL_INTR.ASPIC module. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 12:07 PM 6/11/02 +0100, Jonathan Starr wrote: >Damn, I didn't think of the fact that it will use power even when the main >core is asleep, that won't do. >I have revised the design, it will only sample the ADC when it needs to >alarm, as the ADC value only affects the alarm tone there is no point me >ever doing otherwise...whoops. >As for the wake-on-change I haven't ever used it before so I guess I did >mean RB1 :-) Actually, you need to use either RB0 (INTF) or any of RB4 thru RB7 (RBIF) for wake up. RB1 won't do it! dwayne -- Dwayne Reid <@spam@dwaynerKILLspamplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Thank-you Olin, this looks exactly like the sort of thing I'm after, but I can't get wav_hal.exe to work. I used: C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav It gave me a lot of data about the wav file structure, but no output file (that I could find) I looked in the source, and saw <in> <out> so I tried: C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav output.aspic It said something like 'Invalid token found on line 2, token was 'output.aspic' So how am I supposed to use it :) >>> Olin Lathrop <KILLspamolin_piclistKILLspamEMBEDINC.COM> 11/06/2002 12:47:30 >>> >> Although there is something that somebody may be able to help me with, a long time ago I'm sure I read of someones efforts to reproduce sounds via the PIC using a large RAM table with wave data in it, if anybody thinks they know a link it would be greatly appriciated, as melodys are extreamly hard to code as consecutive delays. << My HAL project produces audio from WAV data stored in program memory. See http://www.embedinc.com/pic/hal.htm. The details of fetching the WAV data, interpolating adjacent samples, and writing to the PWM output are in the HAL_INTR.ASPIC module. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>> C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav It gave me a lot of data about the wav file structure, but no output file (that I could find) I looked in the source, and saw <in> <out> so I tried: C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav output.aspic It said something like 'Invalid token found on line 2, token was 'output.aspic' So how am I supposed to use it :) << That sounds more like the WAV_INFO program than the WAV_HAL program, or a very ancient version of WAV_HAL. Where did you get this version from? Just to be sure, I put up a fresh releases of the PIC development tools and the HAL project. I also added a separate release of the general WAV file manipulation utilities. See http://www.embedinc.com/pic/dload.htm. As an example, I just went to a temp directory and entered: wav_hal /winnt/media/tada -rrate .5 and it made TADA.ASPIC and TADA.WAV files just like it's supposed to. If you install the PICDEV and PIC_HAL releases, please let me know if WAV_HAL then works correctly. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

{Quote hidden}> -----Original Message----- > From: Jonathan Starr [SMTP:RemoveMEJonathanSTakeThisOuTELECTRONIX.CO.UK] > Sent: Monday, June 10, 2002 10:23 AM > To: spamBeGonePICLISTspamBeGoneMITVMA.MIT.EDU > Subject: [PIC]: Waking from sleep on ADC change? > > Hi, this is my first post to the list so I hope it's going to the right > place/formatted correctly :-) > > I'm working on a (commercial) project that involves a 16C73, most of the > other circuit functions are done but I still need to read ADC channel one > (RA0), process the value and create a signal that gets sent to a piezo > sounder. > The ADC is my main problem, I have it reading values, thanks to the > Piclist FAQ, but I need the PIC to sleep for as much of the time as > possible, it's currently sleeping while it converts then it wakes up and I > send its value to the piezo code, but I need then to put it back into > sleep and wait until ADC channel one or RA1 changes (circuit power use is > critical). > I think I can work out how to wake from sleep on RA1 changing, but I don't > even think it's possible to wake from sleep on a change in the analog > input? > You have a problem in both cases. RA1 has no interrupt on change facility, unless this is a typo and you meant RB1? There is no way to wake up from a change in analog value as you suspected, the only wakeup ascociated with the A/D converter is the end of conversion interrupt. The ADC module itself raises power consumption, so depending on how often you need to sample, you might be better off using a timer interrupt to enable the ADC module and the ADC interrupt to disable the module, the aim being to keep the ADC module disabled for as much time as possible. The timer interrupt could be used to check pin RA1 as well (assuming it wasn't a typo). > And, as a side note, does anyone know anything about piezo sounders? > On the sig-gen it's frequency response can only be described as pathetic, > and it appears (annoyingly) to have a sweet spot at 3KHz, the customer > wants a 'Tone' control and as I can't just vary the frequency like I was > hoping to do I'm a bit at a loss. > I think something along the lines of a complex waveform with the ADC value > being used to vary the harmonics would be the way forward, has anyone done > this before? > Common, cheap piezo sounders have a natural resonant frequency as you have found, which is why they are generaly used for single tones, as warning buzzers etc. The resonant frequency and frequency response will be determined to a large extent on how the bare piezo disk is mounted. Obviously if you have a piezo that comes pre-mounted to a plastic casing your choices are limited. I don't think the complex waveform idea is going to help much either, the piezo will only respond to the frequencies around it's resonant point, irrespective if those frequencies are a fundamental or a harmonic of the waveform you generated. You can obtain piezo's with quite a wide frequency response, designed to be used as replacements for small speakers in e.g. laptops. http://www.panasonic.com/industrial/components/pdf/card_speaker_dne.pdf is an example. I suspect they cost considerably more than the common devices used for warning beeps etc. If you could give an idea of the device being used I'm sure that you'd get some suggestions from the list for improved performance. Regards Mike -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Thank you for the link, I was using the version from the Piclist source code archives so it probably was old. I have a problem though, none of the new installers will install: Software installation source directory is C:\WINDOWS\TEMP\WZSE0.TMP\embedinc. No previous installation of this software was detected. Enter where you want the software installed, or hit ENTER to choose the default shown in parenthesis. (C:\embedinc): Running: cmd /c util\fix_attrib *** System error 2 (h00000002). The system cannot find the file specified. INSTALL program aborted due to error in subordinate command. *** Program aborted on error. *** Errors occurred during software installation. Hit ENTER to exit the software installer. It does this on all the installers and it makes no deference where I install it to, my other PC has the same problem with them, but maybe they don't like Win98. Do you posibly have them in a zip file? >>> Olin Lathrop <TakeThisOuTolin_piclistEraseMEspam_OUTEMBEDINC.COM> 12/06/2002 21:43:27 >>> >> C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav It gave me a lot of data about the wav file structure, but no output file (that I could find) I looked in the source, and saw <in> <out> so I tried: C:\WINDOWS\Desktop\hal\embedinc\com\wav_hal.exe winex.wav output.aspic It said something like 'Invalid token found on line 2, token was 'output.aspic' So how am I supposed to use it :) << That sounds more like the WAV_INFO program than the WAV_HAL program, or a very ancient version of WAV_HAL. Where did you get this version from? Just to be sure, I put up a fresh releases of the PIC development tools and the HAL project. I also added a separate release of the general WAV file manipulation utilities. See http://www.embedinc.com/pic/dload.htm. As an example, I just went to a temp directory and entered: wav_hal /winnt/media/tada -rrate .5 and it made TADA.ASPIC and TADA.WAV files just like it's supposed to. If you install the PICDEV and PIC_HAL releases, please let me know if WAV_HAL then works correctly. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.