meron po bang may idea sa inyo kung pano iconvert un digital or analogue meter reading sa type ng data na pwedeng itransmit using gsm module? btw,, okay na po kaya dun un optical sensor?
gagamit pa rin po ba ng pic kahit may sensor na?tnx po ng madami..
i did this in my project in my previous life.
the project needs two thermocouple sensor that is accurate and easily calibrated (iso9000 requirements of the customer).
so instead of building my own thermocouple sensor circuit, we bought an off-the-shelf digital thermocouple thermometer and hacked an interface to connect it to our microcontroller board.
the thermometer we bought uses an ICL7106
http://www.intersil.com/data/fn/fn3082.pdf.
the interface that we built function as follows:
-- detect highest peak of the integrator waveform (see page 5 of the linked PDF)
-- then measure the time until it reaches zero (measurement is done using the internal timer of the mcu, ie., 87c751)
-- perform some arithmetic on the timer count, then i now have the temperature reading. how to select which temperature probe to measure as well as power control for the meter is left to the reader.
thinking of it, i could have just read the 7-segment output of the 7106 and un-XOR it, then make a lookup on a rom table, to find the binary equivalent and repeat until i get all 3.5 digits. this i did consider but i haven't got any spec-sheet for the 7106. oh well.
