a way to make 4channel 0.01V precise voltage

Thread Starter

Eneloop

Joined Jan 4, 2019
4
hi, Im making a over network-contorled drone,
and I hacked a drone controller, made other things but

my system is making voltage different value when i use other power supply (or even when I use same battery but less charged), with same pwm.

so, i'm trying to use DAC.

need to make 1.400~1.900V +-0.01V precission of 4 output channel

can this be the sollution?

=========================================================================

DAC : https://www.analog.com/media/en/technical-documentation/data-sheets/DAC8420.pdf

with 2.5 voltage reffernce chip, single 5V supply system, MCU: arduino micro.
 

danadak

Joined Mar 10, 2018
4,057
Use a 2.048 reference will give you a convenient lsb step of .5 mV / lsb.

Of course you have to do a complete error budget to see if it meets your goals
over T and V.


Regards, Dana.
 

Thread Starter

Eneloop

Joined Jan 4, 2019
4
Welcome to AAC!
Why do you think you need the tolerance to be so tight?
cuz when i tested my controller and drone simullator, from 0.03V the drone started to move.
(you defenetly would not want your drone to move on steady mode)

so, +-0.02V is seems little dangerous, i want to be +-0.01V
 

Thread Starter

Eneloop

Joined Jan 4, 2019
4
Is it really offset that you need to adjust? That should be easier than going for precision of the voltage.
im not sure what you meant but,

the controller have 1.635V at natural(analog stick), and its very sensitive.

so.. the exact voltage is needed rather than offset.

(and i wrote 0.01 but actualy it was 0.001)
 

DickCappels

Joined Aug 21, 2008
7,441
If you only need the voltage to be exactly 1.635V with and the other voltages can be a little off, then you can solve the problem pretty easily with an offset adjustment. As danadak pointed out you will have to be careful to choose a voltage reference that will be stable enough over temperature.
 

Thread Starter

Eneloop

Joined Jan 4, 2019
4
If you only need the voltage to be exactly 1.635V with and the other voltages can be a little off, then you can solve the problem pretty easily with an offset adjustment. As danadak pointed out you will have to be careful to choose a voltage reference that will be stable enough over temperature.
ok, ill try with good voltage references.
thanks lot for the comments
 
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