how to interface electronic sensors with the arm processor

[cool01]

can anyone tel

how to interface electronic sensors with the arm processor and write assembly language program for it
plzzz

 

[arunkumar446]

Re: can anyone tel

if the sensor which ur asking is analog voltage output then use an ADC to convert it to digital and then use interfacing ic's to interface this ADC. Read the data in and do operations what ever you want by writing a code.

 

[askcq]

Re: how to interface electronic sensors with the arm process

hi

if the sensor output is in mV range, should i directly give to ADC

 

[daviddlc]

Re: how to interface electronic sensors with the arm process

You can do i but it's better to adapt the signal and use the full range of the ADC.

For example:

if you have a 12 bits ADC, Vref = 5volts and your input is from 0 to 250 mV, then you use the signal adapter:

Input - Adapter:
0 - 0
250mV - 5V


So you connect your input signal to this scaler and the output of the scaler to the ADC, with this you will have more resolution.

You can use a Op-amp to achieve this.

 

[91divine]

Re: how to interface electronic sensors with the arm process

hi

if the sensor output is in mV range, should i directly give to ADC

As arm contain a 10bit adc with vref as 3.3V, so it can measure value in the step of 3.2mv without any need of amplifier. If this is still large then while programming ADCON reg in arm you can set Vref as 1V, this will decrease the step size to 0.97mv. If still it is greater then go with a standard amplifier with near zero output impedence.

 

[HTA]

The interface needed is driven by the sensor type used. There are sensors with standard analog output(+/-20mA or 0-10V) or some with digital output(like SPI, PWM, ABZ from incremental encoders, IO-Link). The simple form is just a variable resistor as a sensor element(e.g. for temperature) and the sensor signal conditioning is prior to the ADC of the microcontroller. The next level is a wheatstone bridge with diffential signal conditioning. There is the need to design the sensor signal conditioning or use an integrated component. Maybe it is best that you define the type of sensor to want to use and then see what it will need to fit the ADC range of the ARM processor. The software will either use the ADC or has to emulate a digital interface.

Enjoy your desgn work!