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andyf97
- 14th August 2009, 15:39
I have an application requiring accurate temp measurement based on the resistance from a thermistor that is fixed inside a heat sink.

Also I like to have two I/O pins visually to state with LEDS if that temp is above or below two pre set boundaries around 25C.

Lets say the lower boundary is 23c and the upper 27c

If the Temp is < 23C then Red led is on.
If the Temp is > 27C then Blue led is on.

Optionally I like to send that temp every 10ms as a simple serial strings to another device.

I imagine I can do this wit a very small microchip with not so many pins.


Any ideas?








Any ideas?

mackrackit
- 14th August 2009, 17:09
Maybe a 16F676 ?

Jerson
- 14th August 2009, 18:15
Sure it can be done with a PIC+some external active components to read the thermistor. I will second the choice of 676 if you decide to use PIC.

Easily done with a single chip PSoC that has the amp+adc inside. Just another idea you can consider. Of course, you will need to learn it up. It's a different breed of embedded processor. However, the chip is a tad costlier than the PIC mentioned.

Sorry for the deviation, but, you asked for ideas!!!

andyf97
- 15th August 2009, 06:51
Mackrakit, Jerson.

Thank you for your replies,

Jerson, that kit is very smart and flexible and I am sure it can be configured for many applications, I don't mind learning something new if in the end it saves on development time and removes the need to get out the soldering iron to create a circuit. I just wonder if it might be over complex for what i need and 90% of the system could be redundant.

I am very considering buying the kit and trying it because of its fairly low cost, if I go ahead and by it could you help me a bit to get started?

Also the development kit I saw was for RF systems and I wonder if the chips can be ordered and hard wired into an existing system or what is sold is complete module?


One other question.

My end design will have 10 thermistors to check and that means 20 Leds, could this be done with one Psoc chip + some led drivers



Of course I will read more about this as its very interesting but I welcome any pointers you have.

mackrackit
- 15th August 2009, 10:32
My end design will have 10 thermistors to check and that means 20 Leds, could this be done with one Psoc chip + some led drivers
That kind of kills the 676. You will need a PIC with 10 ADCs.
If you go with the PIC solution...

Jerson
- 15th August 2009, 12:09
I don't think this is the appropriate forum to discuss the PSoC. However, I am dropping this hint here for any others who may be interested. The forum for Psoc is well supported at psocdeveloper.com

Andy, if you need any more info, PM me and I'll be glad to get you started.