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I would like some help in putting together some C Code to set-up and read one ADC Channel continuously and also set-up and Scan through multiple ADC channels continuously. I have Codewarrior for HCS12.Some help would be appreciated as I am a newcommer to embedded. |
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ADC HCS12 DP256
Started by ●September 10, 2002
Reply by ●September 10, 20022002-09-10
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In a message dated 9/10/02 10:00:57 AM Eastern Daylight Time, writes: > I would like some help in putting together some C Code to set-up and > read one ADC Channel continuously and also set-up and Scan through > multiple ADC channels continuously. Example for icc12 and hc12a4.... hope its similar....... somewhere in a setup subroutine: ATDCTL2=0xc0; //atd enab ATDCTL4=0x07; //sample rate ATDCTL5=0x70; //continuous scan, multichannel, 8 ch and later in the program: //-------------------- void readads(void){ //read 8 ch of internal a/d into addat[] unsigned char i; unsigned int tmp; unsigned char bh,bl; volatile unsigned char *p; ATDCTL5=0x70; //init multichannel conv while((ATDSTAT & 0x80)==0){}; //wait for sequence finished p=&ADR0H; //point to ch 0 for(i=0; i < 8; i++){ bl=*p++; //lo byte bh=*p++; //hi byte tmp=((unsigned int)bh << 8) | bl; //form word addat[i]=tmp & 0x3ff; //save 10 bit value } } //-------------------- void showads(void){ //show 8 ch of internal a/d unsigned char i; printf("\n"); for(i=0; i<8; i++){ printf("%3d ",i); } printf("\n"); while(!kbhit()){ readads(); for(i=0; i < 8; i++){ printf("%04x ",addat[i]); } printf("\r"); } printf("\n"); } |
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Reply by ●September 12, 20022002-09-12
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Thanks for the help Bob, can you explain to me why line (ATDCTL5=0x70; //continuous scan, multichannel, 8 ch) has to be put in the setup section as well as the conversion section? Please excuse me as I am a hardware engineer who is trying to get to grips with this even though my "C" code ability is basic. My company have just bought metrowerks for HCS12, it has been thrown on my desk and I have been told to get to grips with it!!!! difficult as the 2000 package only comes with a flashing LED program and a CD Rom with 5000 pages of PDF files!, none of which actually contains any useful "C" software routines ( accessing ADC, SPI, CAN,I/O Frequency/Pulse counting)....help!! I am trying to write a series of routines that tests the basic functionality of a custom made Analogue board with ADC, programmable gain amplifiers, programmable offset all accessed by SPI. --- In 68HC12@y..., BobGardner@a... wrote: > In a message dated 9/10/02 10:00:57 AM Eastern Daylight Time, > toby.merridan@s... writes: > > I would like some help in putting together some C Code to set-up and > > read one ADC Channel continuously and also set-up and Scan through > > multiple ADC channels continuously. > > Example for icc12 and hc12a4.... hope its similar....... > > somewhere in a setup subroutine: > ATDCTL2=0xc0; //atd enab > ATDCTL4=0x07; //sample rate > ATDCTL5=0x70; //continuous scan, multichannel, 8 ch > > and later in the program: > //-------------------- > void readads(void){ > //read 8 ch of internal a/d into addat[] > unsigned char i; > unsigned int tmp; > unsigned char bh,bl; > volatile unsigned char *p; > > ATDCTL5=0x70; //init multichannel conv > while((ATDSTAT & 0x80)==0){}; //wait for sequence finished > p=&ADR0H; //point to ch 0 > for(i=0; i < 8; i++){ > bl=*p++; //lo byte > bh=*p++; //hi byte > tmp=((unsigned int)bh << 8) | bl; //form word > addat[i]=tmp & 0x3ff; //save 10 bit value > } > } > > //-------------------- > void showads(void){ > //show 8 ch of internal a/d > unsigned char i; > > printf("\n"); > for(i=0; i<8; i++){ > printf("%3d ",i); > } > printf("\n"); > while(!kbhit()){ > readads(); > for(i=0; i < 8; i++){ > printf("%04x ",addat[i]); > } > printf("\r"); > } > printf("\n"); > } |
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Reply by ●September 12, 20022002-09-12
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In a message dated 9/12/02 4:20:45 AM Eastern Daylight Time, writes: > Bob, can you explain to me why line > (ATDCTL5=0x70; //continuous scan, multichannel, 8 ch) has to be put > in the setup section as well as the conversion section? > That's proabably redundant. Very observant. Original idea was to have all 8 channels continuously convert.... had some prob with that, so I fell back to the version where I initiate conversion.... good luck with metroworks... this list is full of guys looking for docs and tutorials on metroworks... a few of them have conquereed it... I think they are renting themselves out as consultants now... I like the imagecraft compiler... its inexpensive and the guy that wrote it will actually answer your questions if you have any... |
Reply by ●September 12, 20022002-09-12
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Have a look as well on http://e-www.motorola.com/index.html there are a lot of application notes with code around ADS/SPI/etc as well. Erich > -----Original Message----- > From: hellfire1272000 [mailto:] > Sent: Thursday, September 12, 2002 10:19 AM > To: > Subject: [68HC12] Re: ADC HCS12 DP256 > Thanks for the help Bob, can you explain to me why line > (ATDCTL5=0x70; //continuous scan, multichannel, 8 ch) has to be put > in the setup section as well as the conversion section? > > Please excuse me as I am a hardware engineer who is trying to get to > grips with this even though my "C" code ability is basic. > My company have just bought metrowerks for HCS12, it has been thrown > on my desk and I have been told to get to grips with it!!!! difficult > as the 2000 package only comes with a flashing LED program and a CD > Rom with 5000 pages of PDF files!, none of which actually contains > any useful "C" software routines ( accessing ADC, SPI, CAN,I/O > Frequency/Pulse counting)....help!! > > I am trying to write a series of routines that tests the basic > functionality of a custom made Analogue board with ADC, programmable > gain amplifiers, programmable offset all accessed by SPI. > --- In 68HC12@y..., BobGardner@a... wrote: > > In a message dated 9/10/02 10:00:57 AM Eastern Daylight Time, > > toby.merridan@s... writes: > > > > > > > I would like some help in putting together some C Code to set-up > and > > > read one ADC Channel continuously and also set-up and Scan > through > > > multiple ADC channels continuously. > > > > Example for icc12 and hc12a4.... hope its similar....... > > > > somewhere in a setup subroutine: > > ATDCTL2=0xc0; //atd enab > > ATDCTL4=0x07; //sample rate > > ATDCTL5=0x70; //continuous scan, multichannel, 8 ch > > > > and later in the program: > > //-------------------- > > void readads(void){ > > //read 8 ch of internal a/d into addat[] > > unsigned char i; > > unsigned int tmp; > > unsigned char bh,bl; > > volatile unsigned char *p; > > > > ATDCTL5=0x70; //init multichannel conv > > while((ATDSTAT & 0x80)==0){}; //wait for sequence finished > > p=&ADR0H; //point to ch 0 > > for(i=0; i < 8; i++){ > > bl=*p++; //lo byte > > bh=*p++; //hi byte > > tmp=((unsigned int)bh << 8) | bl; //form word > > addat[i]=tmp & 0x3ff; //save 10 bit value > > } > > } > > > > //-------------------- > > void showads(void){ > > //show 8 ch of internal a/d > > unsigned char i; > > > > printf("\n"); > > for(i=0; i<8; i++){ > > printf("%3d ",i); > > } > > printf("\n"); > > while(!kbhit()){ > > readads(); > > for(i=0; i < 8; i++){ > > printf("%04x ",addat[i]); > > } > > printf("\r"); > > } > > printf("\n"); > > } > > > > > > > > > > > -------------------- > > ">http://docs.yahoo.com/info/terms/ |
