Den 10.01.2015 22:07, skrev Ssagarr Patil:
Hi Noralf,
Date: Sat, 10 Jan 2015 14:50:09 +0100
From: notro@xxxxxxxxxxx
To: hugarsagar@xxxxxxxxxxx
CC: linux-fbdev@xxxxxxxxxxxxxxx
Subject: Re: SSD1306 OLED driver
Den 10.01.2015 13:34, skrev Ssagarr Patil:
Hi Noralf,
I am now concerned if the driver was tested in first place ?
No. I just submitted some good looking code that never ever got
tested.
More seriously, There's a few thing that comes to my mind:
- Your controller doesn't behave the same way than the ones already
supported.
- You haven't posted your changes yet, so maybe you're not doing the
transfers right
- Your SPI controller is doing something weird
What happens if you plug a logical analyzer on the bus?
Maxime
Hi,
The major difference between the SSD1306 SPI and I2C interfaces, is that
SPI uses a D/C pin to signal whether it's data or command coming in.
Looking at ssd1307fb, this Data/Command info is embedded as the first
byte in the i2c package/message.
Without looking up the datasheet, I would guess that this is the only
difference, the way the D/C bit is handled.
The rest of the package payload should be the same.
So:
dc=0, spi write command
dc=1, spi write data (optional)
I was working on ssd1306 itself.
Apart from that, I have SSD1306 SPI support in a project of mine:
This is the part writing the framebuffer:
https://github.com/notro/fbtft/blob/master/fb_ssd1306.c#L173
This writes commands (for many controllers):
https://github.com/notro/fbtft/blob/master/fbtft-bus.c#L10
This is the SPI specific part:
https://github.com/notro/fbtft/blob/master/fbtft-io.c#L10
Project wiki: https://github.com/notro/fbtft/wiki
Thanks for the pointers that was really helpful.
just a quick help the dc pin should be a gpio and be set as output pin
to control D/C ?
Correct.
Thanks!
Is there any sample app/library to draw/test this driver?
I find it easy to just use the framebuffer console for simple testing:
con2fbmap (or X windows)
I have also used Geert's fbtest.
Noralf.
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