I have a problem trying to use my 160x128 Color OLED display when uploading a welcome screen to it. It gives me the "no welcome screen" message when booted, after I cycle the power once its finished with the upload. This display has firmware 2.8 installed, so I don't think it has the MSB/LSB swap that Digole said they changed in 2.9 and higher.

I can take this same welcome screen and upload it to my 96x64 Color OLED and it works just fine. Has something else changed between 2.8 and 2.9 that would affect how the welcome screen would work on the Color OLED displays? I've tried swapping the program size LSB/MSB sizes in case that changed happened in 2.8 and not 2.9, but no difference.

I am using the SPI interface with all my displays.

This is a snipit of my welcome screen data that I upload (to my command that issues a "SSS", followed by the low byte of the total length (including the command table size bytes), then the high byte of the length):

{

// size of command table

 0x99,0x07,

// set color to white

'S','C',0xff,

// set the display mode to copy

'D','M','C',

// draw full screen white box

'F','R',0x00,0x00,0x9f,0x7f,

// draw centered logo

'E','D','I','M','1',0x36,0x2d,0x34,0x25,

 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,...

<lots of data>

};

Has something else changed in the firmware that we need to take in account or is this specific to the 160x128 Color OLED? I've tried two different 160x128 Color OLED displays so I know it's not a bad board. Thanks.

Brett

 2 table length needed: if the pure welcome screen information is X bytes, you need put this X value (2 bytes) at the beginning of the pure data to indicate the MCU how many bytes need to be read.

But when you download the full welcome screen data(it's X+2 bytes now) to module, you also need tell the moudle how long of the data follow to "SSS" commmand, here is the command format:

"SSS"

(X+2)

(X)

real welcome screen data........

The (X+2) is for "SSS" command, and the (X) is for MCU when loading welcome screen.

We removed this tricky in new firmware version of V3.3, in V3.3, only one length follow to "SSS" command needed. When the module loading the welcome screen data when power up, it will load the data byte by byte, UNTIL value of 255 met and this value not belong to last command，this solution will let you put any dummy data(but not 255) in the welcome screen, eg.:

"TTHello World!\x00\xff"

In the above welcome screen data, the "\xff" not belong to the "TT" command, due to the "TT" command was endded by "\x00", so, this "\xff" used to indicate the welcome screen end here.

This technical make the old welcome screen data compatible with the new version too.

Please also refere to:

http://www.digole.com/forum.php?topicID=13

 That's all well and good, but I think you were not answering the question I actually asked. I have the welcome screen working just fine on the 96x64 OLED Color display, as I know all about the command table needing the actual size as its first member, and that the SSS command has this additional length word added to it. The problem is the 160x128 OLED Color display with 2.8 firmware does not act the same when being sent the same exact datat as the 96x64 OLED Color display. I have no idea what firmware version it is running now since I have this welcome screen now running on the 96x64.

Why would something on 2.8 not work with this code? I literally have a ATMEGA MPU flashed with an uploader program and I can upload to the 96x64 and have it work just fine, and then connect to the 160x128, upload and get the "no welcome screen" message.

 Try to switch the the 2 bytes for X value, in the new version of firmware, it like this: X/266, X%256, but old version was reversed, we made it massed before, and now all 2 byte integer of sequence are identical now. 

 As stated in the original post here, I already tried changing the LSB/MSB in the command table size in the data, even though Digole posted in these forums this change was only done from version 2.9 and up (as I also mentioned I am on 2.8). Are you saying it was changed earlier than 2.9 now? And do you also mean switching the "SSS" command length too, as that is also currently LSB followed by MSB.

 Well just tried with switching the LSB/MSB order in the command table, no change. Tried switching both LSB/MSB in command table and SSS command, SSS command failed saying program was too big, as I assume the swapping of SSS command length made a crazy large number (so that obviously should not be changed). Weird thing is it actually ran my welcome screen after the SSS command failed and before a reboot, so I saw what I would expect on a reboot. Actually rebooting the display gives the same "no welcome screen" message though.

So something is obviously different about this firmware, can you tell me what it is? Can I get source code to the firmware as it seems Digole makes random changes each version, which they don't document and have been affecting our development.

 SSS (X+2) (X) .......X length of data

What I remember is in old version, the (X+2) (X) are LSB MSB sequence, and later change (X+2) to MSB LSB sequence, and now, both (X+2) (X) are in MSB LSB, but forgot which version changed, I will check the programming document tomorrow.

Okay, I look forward to hearing what the actual 2.8 firmware is expecting from the SSS command, as I tried all these options with no change. Thanks.

 I checked your order history, the 1.8" OLED module you ordered in March 2015 supposed use:

SSS(LSB MSB X+2)(LSB MSB X)(..........X data), please try this format and let me know if that work.

Okay, I've tried that, and it gives me the "no welcome screen" message. This was the original issue as I took the working MPU with my upload program that was working on the 0.96" OLED and tried to use it on the 1.8" and it didn't work. I've tried it on multiple 1.8" OLED displays with the same results.

Uploading fonts works fine (as long as I don't use anything over 3.5K in size) on the 1.8" OLED, so I can send data to the firmware. The welcome screen just does not work.

I found the document: the data length of welcome screen on 1.8" module with old version, limitation is 1918 bytes

That was the issue, once I made the image graphic smaller I was able to get it to work. Thanks!

So the different displays have different sizes for the welcome screens? Is this documented anywhere?