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Converting a PWM wave so ADC-11 can read it!

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Converting a PWM wave so ADC-11 can read it!

Postby kcj » Sat Jan 28, 2012 11:50 pm

Hi All,

I have a question regarding measuring voltage output using PICO ADC-11datalogger. Currently my project has been to measure force via xbee and display the data via a 16x2 LCD using PIC 18F13k22. That pic does not have a DAC converter so i have been using a PWM to output the volts and that output wave is square.

I have tried connecting the pico data recorder to record the voltage but it does not register the voltage, i am asssuming because it is square but i am new to electronics and am not sure.

How do you convert the signal into a readable signal for the voltage recorder, using the Picoscope i can see the square wave, The xbee send a range from 0 to 1.2 volts max.

Thanks
kcj
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Re: Converting a PWM wave so ADC-11 can read it!

Postby Martyn » Mon Jan 30, 2012 9:52 am

What voltages are you trying to look at with the ADC-11 and what is the frequency of the signal ?
How have you configured the PicoLog software ?

You may wish to send in a more detailed request to support@picotech.com
Martyn
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Re: Converting a PWM wave so ADC-11 can read it!

Postby kcj » Mon Jan 30, 2012 9:55 pm

The Voltages for PWM are 0 to 3.3v and the average volt is 0 to 1.2 volts. I am unsure of the frequency but a pulse period is 20ms. I dont think i have configured PICOLOG, my software included Pico Scope, Pico recorder and Pico player. I have heard a low pass filter below the PWM frequency could maybe smooth Vout. I have not been able to try that out yet.
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Re: Converting a PWM wave so ADC-11 can read it!

Postby Martyn » Mon Feb 06, 2012 9:08 am

Pico Recorder/Pico Player are Picolog. When you first start the recorder you will create a settings file which includes how quickly you sample the signal. I would suggest you start the Recorder and go to File->New Settings to set it up again.
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