alberteerj
Newbie level 3
i'm currently developing a humidity sensing for my board.
I'm using a Humidity Resistance CHR-O1 sensor from Cybersen product. As mentioned in the datasheet, the sensor uses AC 1V (50 ~ 2 K Hz) supply.
I'm using a 555 timer to generate the pulses and the expected output will be in frequency. But i need to output the signal into ADC board that is using a Vref 4.2V.
I notice someone have suggested using a 2917 or two 555.
If using two 555, one is in Monostable and the other is Astable mode. how do i connect the circuit between two 555? Which type of modulation i should use?
I'm using a Humidity Resistance CHR-O1 sensor from Cybersen product. As mentioned in the datasheet, the sensor uses AC 1V (50 ~ 2 K Hz) supply.
I'm using a 555 timer to generate the pulses and the expected output will be in frequency. But i need to output the signal into ADC board that is using a Vref 4.2V.
I notice someone have suggested using a 2917 or two 555.
If using two 555, one is in Monostable and the other is Astable mode. how do i connect the circuit between two 555? Which type of modulation i should use?