Newhaven Display Forum

Newhaven Products => OLEDs => Topic started by: msp-ssi on November 02, 2014, 04:11:05 AM

Title: NHD-0220DZW-AY5, spi, beaglebone
Post by: msp-ssi on November 02, 2014, 04:11:05 AM
I'm trying to get an NHD-0220DZW-AY5 OLED character display to work with a Beaglebone black over SPI.

The display module jumpers are configured for serial mode and I'm sending the commands listed in the datasheet over SPI. So far, I'm not seeing any life signs from the display, it's just dark. I've used a logic analyzer to check what is being sent over the serial lines.

Has anybody been able to get this display to work in serial mode? Any help or pointers are appreciated. I'm attaching the output from the logic analyzer for the first command in the initialization sequence. (The rows are MOSI, MISO, Clock, Enable in that order and the clock is running at 1.5 MHz.)

Thanks!

Title: Re: NHD-0220DZW-AY5, spi, beaglebone
Post by: 404 on November 03, 2014, 03:22:46 AM
Have you verified that your supply voltage and logic levels are within spec?
Title: Re: NHD-0220DZW-AY5, spi, beaglebone
Post by: msp-ssi on November 03, 2014, 03:50:48 AM
A logic zero is 0,196 V and a one is 3,235 V.
Supply voltage is between 3,294 V and 3,313 V.
Title: Re: NHD-0220DZW-AY5, spi, beaglebone
Post by: msp-ssi on November 10, 2014, 02:33:43 PM
This issue got resolved.

Handling the pins as GPIO pins and explicitly clocking in the data instead of trying to treat the display as an SPI device solved the issue.