SPI or I2C better for 2 lcd displaying same data?

Thread Starter

GoExtreme

Joined Mar 4, 2018
52
Im working on a voltmeter that will requires LCD's in different spots. 2 or 3 LCD's will display the same data.
My current design has i2c oled on different addresses but wondering if SPI with clock select to few screens at once will work?
 

joeyd999

Joined Jun 6, 2011
4,433
Im working on a voltmeter that will requires LCD's in different spots. 2 or 3 LCD's will display the same data.
My current design has i2c oled on different addresses but wondering if SPI with clock select to few screens at once will work?

It'll work for writing data only. You will not be able to read back data or status. There will be SDO contention.
 

Ian Rogers

Joined Dec 12, 2012
810
I2C normally has 8 addresses.... How far will the display be from the controller? I2C doesn't travel far! You may be better off with 485..

I have done CS on two screens, One had a not gate so when one was active the other wasn't and visa versa... ( well a transistor as a not )..
 

Thread Starter

GoExtreme

Joined Mar 4, 2018
52
I have room for multiple CS. However I think I2C is fast enough for what I need. I was just thinking with SPI maybe I could refresh screens at the same time by having 2 or 3 CS selected at the same time.
 

dendad

Joined Feb 20, 2016
3,611
If you have both screens at the same I2C address, and you are only writing to them, just treat them as a single display and both should show the same info.
 
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