# VOLTAGE DROP FROM 3.3 V TO 2.0 V FOR ANALOGUE READINGS?

**URL:** <https://community.sparkfun.com/t/voltage-drop-from-3-3-v-to-2-0-v-for-analogue-readings/42152>\
**Category:** Artemis\
**Created:** [May 16, 2021, 10:10am UTC](https://community.sparkfun.com/t/voltage-drop-from-3-3-v-to-2-0-v-for-analogue-readings/42152 "2021-05-16T10:10:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rakeshpatel](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rakeshpatel](https://community.sparkfun.com/u/rakeshpatel)\
**Post date:** [May 16, 2021, 10:10am UTC](https://community.sparkfun.com/t/voltage-drop-from-3-3-v-to-2-0-v-for-analogue-readings/42152/1 "2021-05-16T10:10:17Z")

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As the title suggests, I want to use the Artemis for a business that includes taking simple readings (temperature readings using thermistor tests). With my current MCU, it’s simple, as I can just use high efficiency from an advanced spindle, but that’s not really an option here.

I am concerned about the power usage so I should have the option to turn the test circuit on and off. Again, pretty straightforward using the advanced pin.

I’m decently new to this area, and several general thoughts, but I might really want to hear from more experienced people on the prescribed procedures and assumptions.

The perspectives I have considered are:

1. Using a voltage divider, but the test circuit itself is a voltage divider circuit, so I don’t know what the impact of their bonding will be, or what the force contemplations look like here

2. Using a BJT semiconductor as a change from an external power source and then using LDO or Zener diode (s) to further reduce the voltage depending on the situation.

Very appreciated

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**Author:** ![adam.g](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@adam.g](https://community.sparkfun.com/u/adam.g)\
**Post date:** [May 16, 2021, 4:15pm UTC](https://community.sparkfun.com/t/voltage-drop-from-3-3-v-to-2-0-v-for-analogue-readings/42152/2 "2021-05-16T16:15:56Z")

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Hi @rakeshpatel,

Out of curiosity, which Artemis board are you looking to use?

In my experience, analog readings with the Artemis have never been straightforward. A voltage divider is one of the most common methods of scaling down the voltage, but if you’re using the MicroMod Artemis you can forget about it. You end up with a loaded voltage divider due to the op-amp circuitry, which I’ve yet to get to work.

See:

[https://github.com/sparkfun/MicroMod\_Ar … r/issues/3](https://github.com/sparkfun/MicroMod_Artemis_Processor/issues/3)

[https://github.com/sparkfun/MicroMod\_Ar … r/issues/4](https://github.com/sparkfun/MicroMod_Artemis_Processor/issues/4)

Paul Clark uses a 2 MOhm/1MOhm voltage divider with the OpenLog Artemis to measure the battery voltage, but the Artemis has a real problem with high impedance and requires an additional correction factor.

See:

[https://github.com/sparkfun/OpenLog\_Art … -637387632](https://github.com/sparkfun/OpenLog_Artemis/issues/11#issuecomment-637387632)

Others may be able to provide more insight!

Cheers,

Adam