I'm struggling a little bit with using the ADC on an ESP8266 module. Its 1V max. I'm looking at this from 2 perspectives.
1) If I want to interface something like a photoresistor then I could use the 3.3 or 5V supply and put it through either a zener diode or a voltage regulator or a precision voltage reference and use that as the Vsupply for the measuring circuit. What are the pros and cons of each method?
A search on digikey results in no throughole 1V voltage references and no 1V zeners whatsoever. Same for voltage regulator. Arggh. Any suggestions?
2) Some modules, not simple components above put out up to 5V as a signal. Is there a way/circuit to build an analog autoscaler that will translate a 0-xV DC range into a 0-1V range?
[update] Sorry forgot to add that I do know I can just use a voltage divider on the output of the sensor or module. However, that requires a different set of resistors for each module based on the max Vout. Not necesarily. see update 3 below. I want something generic if possible.
[update2] I'm thinking I need some kind of opamp circuit that scales the voltage down. An inverting opamp can have a gain of less than one but the output is negative polarity.
[update3] Well that was fun. It turns out that the two resistor method to divide the output is the only method I need if I assume the output range is always 0-5V or 0-3.3V. However, if I could get a 1V reference voltage I could see that as being useful.
0-5V range: 12K and 3K or 10.2K and 2.55K
0-3.3V range: 6.2K and 2.7K
https://e2e.ti.com/blogs_/b/analogwire/archive/2016/09/20/three-ways-to-scale-an-analog-input-signal
1) If I want to interface something like a photoresistor then I could use the 3.3 or 5V supply and put it through either a zener diode or a voltage regulator or a precision voltage reference and use that as the Vsupply for the measuring circuit. What are the pros and cons of each method?
A search on digikey results in no throughole 1V voltage references and no 1V zeners whatsoever. Same for voltage regulator. Arggh. Any suggestions?
2) Some modules, not simple components above put out up to 5V as a signal. Is there a way/circuit to build an analog autoscaler that will translate a 0-xV DC range into a 0-1V range?
[update] Sorry forgot to add that I do know I can just use a voltage divider on the output of the sensor or module. However, that requires a different set of resistors for each module based on the max Vout. Not necesarily. see update 3 below. I want something generic if possible.
[update2] I'm thinking I need some kind of opamp circuit that scales the voltage down. An inverting opamp can have a gain of less than one but the output is negative polarity.
[update3] Well that was fun. It turns out that the two resistor method to divide the output is the only method I need if I assume the output range is always 0-5V or 0-3.3V. However, if I could get a 1V reference voltage I could see that as being useful.
0-5V range: 12K and 3K or 10.2K and 2.55K
0-3.3V range: 6.2K and 2.7K
https://e2e.ti.com/blogs_/b/analogwire/archive/2016/09/20/three-ways-to-scale-an-analog-input-signal
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