Siva kumar

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11 years, 9 months ago.

How to send data to the SSD1305 LCD driver

Hello, I am working on a project that employs the SSD1305 LCD driver. It is interfaced via SPI protocol. Going through the Datasheet I understood about the different addressing modes and SPI commands, but I am still confused about how to send the data to the GDDRAM.

I got the sample codes from spk_oled_ssd1305. But I am still unclear, how the data is sent to the RAM,

1. If I have to send a character or a string, should it be send as ASCII characters, since each segment is of 8 bits?

2. If I have to display an Image, how can I do it?

I am a newbie to such kind of development. Any suggestion would be a great help.

Thanks and Regards Siva

Question relating to:

Last updated: 30 Jun 2012

2 Answers

Wim Huiskamp
11 years, 9 months ago.

Graphics LCD controllers like the SSD1305 typically only support displaying of the pixels that are stored in their memory. You must load that memory with bitmaps representing lines, pictures or symbols. Simple libraries will only support writing individual pixels to the screenmemory. In that case you must translate the imagefile or character that you want to show into many individual write operations. However, more advanced libraries will have support for writing an ASCII character or even complete string. The library uses a bitmap fonttable to translate the ASCII code into the required individual pixels. You can sometimes change the fonttable to get different size or type of font. Advanced libs will also support displaying of bitmap images by providing a filename or a pointer to an image in mbed memory. So the features you get and they way you need to call them depends on the lib you choose. Study the API to select the best one for your needs.

Oliver Broad
11 years, 9 months ago.

The datasheet looks pretty incomprehensible, but to me it looks as if you're writing to the display RAM directly, meaning you're able to write raw bitmap data directly.