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Can chip select be tied low for SPI OLED (PRODUCT ID: 661)
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Can chip select be tied low for SPI OLED (PRODUCT ID: 661)

by seanspotatobusiness on Sun Sep 19, 2021 1:34 pm

Hi. I'm juggling a few options as I try to decide between the I2C and SPI OLED displays based on the GPIO pins they will use and I have two questions regarding the SPI display (PRODUCT ID: 661). It has a chip select pin (CS) but I'm only going to be using one SPI device. Will this display be happy with the CS pin tied low (I know some devices require a falling edge)? Secondly, I read that another reason to include the CS, even if there is only one peripheral device is that devices can get out of sync and the CS pin would be needed to be able to resynchronise - do that apply here as well? Thanks.

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Re: Can chip select be tied low for SPI OLED (PRODUCT ID: 66

by seanspotatobusiness on Mon Sep 20, 2021 3:51 pm

To answer my own question, the chip select is needed because the displays can indeed get out of sync otherwise. I2C it will have to be, especially since the new ones don't need a reset pin any more.

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Re: Can chip select be tied low for SPI OLED (PRODUCT ID: 66

by alphanumeric on Tue Sep 21, 2021 4:26 am

Why not use SPI and CE? I've done it with no issues, with two LCD's on SPI 0 and three on SPI 1. No issues other than a few extra wires, versus i2c.

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