sensor in gpio

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1

Hi,

I'm a newbie on working with embedded boards and need to connect an
analogous sensor of pressure by gpio.
this pressure sensor are fully compensated and amplified. The 0.5 V to
4.5 V analog output voltage signal is linearly proportional to input
pressure.

Until now I have lowered the voltage output with a voltage divider an
50mV.

Hopefully somebody can help giving me some tips in order to accede
the data or point me to the right direction.

Thank you .

2

So, how is the changing data communicated out the GPIO pin? A level 1 or a Level 0 are the only two states a GPIO pin will understand. Is the data serial in nature?

Gerald

3

Hi,
As from what i know and what i believe the sensors cannot be directly interfaced…u need to choose a Analog to Digital converter which takes the analog input from Pressure sensor and convert that to digital form at frequency rate u desire…once the conversion happens usually a register-bit is set and this bit setting u need to program as source for ur interrupt generation(if in case u are not polling the ADC at regular intervals)for which the processor(OMAP) executes a ISR.The ADC address also needs to be IO mapped…

Ganesh

4

Hi,
  As from what i know and what i believe the sensors cannot be
directly interfaced....u need to choose a Analog to Digital
converter which takes the analog input from Pressure sensor
and convert that to digital form at frequency rate u
desire....once the conversion happens usually a register-bit
is set and this bit setting u need to program as source for
ur interrupt generation(if in case u are not polling the ADC
at regular intervals)for which the processor(OMAP) executes a
ISR.The ADC address also needs to be IO mapped...

Ganesh

A basic 555 timer can be setup to do it. Configure it as a basic
PWM generator with the sensor as the input to the PWM. Have the
output drive a transistor (i.e. 2N2222) in common emitter
configuration. No SMT required and there are tons of documents on
this sort of thing. The 555 just configures the sensor output to a
duty cycle and the single transistor provides level shifting.

Softwarewise, just measure the duty cycle on the GPIO pin or use
the input captures.