topic Re: demo9s08qg8 - Getting the tempature sensor going from ADC module in 8-bit Microcontrollers

demo9s08qg8 - Getting the tempature sensor going from ADC module

bobh — Tue, 20 Nov 2007 23:21:50 GMT

Does anybody have the 'C' code function calls to get the ADC temperture sensor taking measurements on the demo9s08qg8 board when the ADC bean wizzard was used to put the ADC module in the project ?

Thanks,

Bob H

Added p/n to subject.

Message Edited by NLFSJ on 2007-11-20 10:58 AM

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

peg — Wed, 21 Nov 2007 05:08:25 GMT

Hi Bob,

It is all explained in AN3031.

http://www.freescale.com/files/microcontrollers/doc/app_note/AN3031.pdf?fsrch=1

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

bobh — Fri, 23 Nov 2007 02:42:33 GMT

Do you know where the if project associated with the application note is stored somewhere on the Freescale website. I cannot find it.

Thanks,

Bob H

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

peg — Fri, 23 Nov 2007 03:42:37 GMT

Hi Bob,

I don't know that there is any.

You could also look at the quickstart, posted in the stickies at the top of this forum.

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

bigmac — Fri, 23 Nov 2007 09:48:59 GMT

Hello Bob,

Here is a reference to an earlier post which discusses single temperature calibration calculations.

http://forums.freescale.com/freescale/board/message?board.id=8BITCOMM&message.id=6667

Fixed point calculations are assumed, since the available resources for the QG8 will usually be insufficient for floating point operations.

Accuracy and resolution using the internal sensor is poor, and the measured temperature will include any self-heating of the die. The main reason for accuracy limitation is that the output of the internal sensor is not amplified before being applied to its input of the ADC. If you need better accuracy and resollution, an external temperature sensor device is a better choice, with typically six times voltage slope, compared with the internal sensor.

Regards,

Mac

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

bobh — Fri, 23 Nov 2007 20:49:50 GMT

Thanks for the information. I was just expermenting with the Code Warrior projects and thought that the temperature sensor would be a good project to see how the hardware interacts with the events part of the bean wizzard. It looks to me though that the software still needs some work.

Thanks,

Bob H

Re: demo9s08qg8 - Getting the tempature sensor going from ADC module

bobh — Fri, 23 Nov 2007 22:39:03 GMT

It looks to me that the MPXY8300 pressure chip from Freescale has all of the functions I am looking for to experiment. Can you program the MPXY8300 with Code Warrior 6.0 for the Flexis series IDE ?

Thanks,

Bob H