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Topic: powering device at 1.8V (Read 268 times) previous topic - next topic

aapatil

Hello!

I am trying to power my AK09970N with 1.8V. Would the Arduino Pro Mini (Atmega328) allow 1.8V? I understand that it allows an external power source, but I am concerned that 3.3V is the minimum allowed.

Thank you!

srnet

Hello!

I am trying to power my AK09970N with 1.8V. Would the Arduino Pro Mini (Atmega328) allow 1.8V? I understand that it allows an external power source, but I am concerned that 3.3V is the minimum allowed.

Thank you!
The datasheet for the Atmega328 suggests that it will operate at 1.8V and CPU clock speed should be no more than 4Mhz.

Datasheets are great places to check out this sort of stuff.
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aapatil

I understand the atmega chip can handle the 1.8V. I am just unclear about how the regulator affects the voltage/works. Just to clarify, I should not be concerned about the regulator limiting anything?

srnet

I understand the atmega chip can handle the 1.8V. I am just unclear about how the regulator affects the voltage/works. Just to clarify, I should not be concerned about the regulator limiting anything?
An odd question.

If you feed 1.8V into the RAW pin (the external power source) of a 5V or 3.3V Pro Mini who knows how the regulator will perform when it does not have enough input voltage to operate ?

How are you going to reduced the clock speed of the Pro Mini to 4Mhz ?
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Wawa

Digital switch points for a proMini are <0.3*VCC for a LOW and >0.6*VCC for a HIGH.

If you are using a 3.3volt (8Mhz) ProMini, then the MCU expects a digital HIGH of at least 0.6*3.3= 1.98volt.
A device powered with 1.8volt can't deliver that.

Two ways to solve this.
1) adding a level shifter breakout board.
2) running the Arduino on a lower voltage.

The Arduino stops working below a certain supply voltage.
That can be fixed by lowering the clock frequency to 4Mhz, and configuration changes.
Leo..


hammy

#5
Jul 21, 2018, 10:38 am Last Edit: Jul 21, 2018, 10:40 am by hammy
I think the post is not clear - I've taken it he wants to get the Arduino to power his sensor at 1.8v... so ...Not sure why you need to do this , the magnetic sensor you have chosen will work at higher voltages - look at the data sheet closely . It gives current drain at 1.8v , but this is not the limit of its power supply . You may still have problems with logic levels , but study the data's sheets , 3.3v may do it for sensor and processor - I haven't bothered looking closely

TomGeorge

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html

Is this associated with this thread?

http://forum.arduino.cc/index.php?topic=559128.0

What is a AK09970N?
How do you communicate with it?
Can you post link to data/spec sheet?

Thanks.. Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

TomGeorge

Hi,
I did it for you, the device will work up to 3.6V, so 3.3V will work.
If you are trying to save current I'd say the power supply will consume more power than the device.

Why do you want to use 1.8V, what is wrong with 3.3V or 5V?
What is the application?

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

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