Analog input sampling rate

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1

Dear Community,

could anyone tell me at what rate the 8 analog inputs of the board can be sampled?

I found this: http://beaglebone.cameon.net/home/reading-the-analog-inputs-adc — but 125ns per channel are hard to believe (this would be 8MHz).

I am a beginner, so I would use the analogRead command…

Ideas? Suggestions?

Thank you!

2

Only 7 input pins (AIN-[0-6]) are connected to header pins. AIN-7 is hard connected to the power supply on the board.

I don’t know what you mean by analogRead command. The TSC_ADC_SS can sample 8 channels at 200 kHz. You can sample at that speed by using libpruio (bindings for C and FreeBASIC are available).

BR

3

Hello,

Using libpruio,

may I ask if there is any support for reading an I2C sensor via the PRU – or any suggestion on how this can be done? The idea is to read an I2C accelerometer in determined intevals, using the PRU, at 1kHz +.

Thanks a lot!

Best regards,

Istvan

4

Hi Istvan!

There’s no I2C support in libpruio and it isn’t planed to get implemented, sorry.

1 kHz should be possible to realize on ARM. (For hard real-time requirements use the second PRU.)

Regards