[display] Improved SSD1306, Support for SH1106

[TomSaw]

Support SH1106

Various SSD1306 Displays sold today do actually integrate the cheaper SH1106. This thing is said to be compatible with SSD1306 what's not 100% the case: SH1106 does only support Page MemoryMode. thus requires a different writeDisplay() routine than actually used for modm::Ssd1306.

Current result using modm::Ssd1306 with SH1106 looks lke this

When sending a frame, one has to alternate between setting the incremented page-address and sending page-data.

However, SSD1306 can also be driven in MemoryMode::PAGE but would result in worse performance vs. transmitting the whole frame at once.

Solutions

1. Create a class Sh1106 inheriting Ssd1306 and override for the differences.
2. Pass MemoryMode as template parameter to Ssd1306 and specialize for the differences.
3. Pass Ssd1306_I2cWriteTransaction as template parameter and handle the differences there.

I've choosen 1. because:

• SH1106 is a different IC and deserves it's own class. The compatibility to SSD1306 is expressed by the strong inheritance on Ssd1306
• Solution 3. sounds elegant but results in more complex code cause way more binding is required between SSD1306 and Ssd1306_I2cWriteTransaction.
• One does not want to drive SSD1306 in MemoryMode::PAGE due to worse performance. This excludes 2. and 3 additionally

Improved SSD1306

Structure

• Detailed Registers in own header ′ssd1306_register.hpp′
• Renamed DataTranmissionAdapter -> Ssd1306_I2cWriteTransaction for clarification
• removed numerous cumbersome WriteData() methods

Performance

• Bulk data transmissions
  • Much faster Initialize() and slightly faster writeDisplay()
  • Size of commandBuffer could be halfed
• Simplified Ssd1306_I2cWriteTransaction

Changes on MonochromeGraphicDisplay

• Flipped buffer[x][y] to buffer[y][x] to be compatible with SH1106
  Current layout of the buffer is not compatible with the memory of SH1106. For SH1106 we need the rows ( x-dimension) being ordered behind each other rather than the columns.
  SH1106 unfortunately offers no other options to adjust the mapping. Kindly Ssd1306 comes to meet these constraints and archieve max performance for both displays. We can switch from MemoryMode::VERTICAL -> MemoryMode::HORIZONTAL so both displays expect the rows in a line and the common ′buffer′s dimensions could be flipped.

[TomSaw]

Cool. This think looks fine to me. Could you please review @salkinium !?

[salkinium]

Very nice! Perhaps split into two commits, one for the display changes and one for the driver code.

[TomSaw]

Clean. if you're happy, merge pls!

[TomSaw]

Ready to merge, sir!