When the ePaper initialize block is used, it sets up the Propeller microcontroller to communicate with the ePaper module. The ePaper initialize block installs 1 small font, which allows you to print text and numbers to the ePaper module’s screen. You may want to use a medium or large sized font instead. In order to use different fonts, you will have to install them into the EEPROM memory on your Activity Board.
The EEPROM memory on the Activity Board can hold up to 64 kilobytes (KB) of data. The first 32 KB is used to hold your programs when you click “Save to EEPROM”. The remaining memory — often called upper EEPROM — is used to hold information that can be accessed by the programs you write for your Activity Board.
The chart below illustrates how the EEPROM is used. When you install the ePaper fonts, they use about 23 KB of EEPROM memory:
If you look carefully at the example chart above (though your program may not have ActivityBot calibration data in the EEPROM), when fonts are installed, there are about 7.8 kilobytes available for other uses. In BlocklyProp, that area is accessible via the Memory > EEPROM blocks.
Installing the ePaper fonts does not actually require any circuits, not even the ePaper module itself. The program to install ePaper fonts is only a single block.
Four Fonts, Three Sizes — The default Sans font style does not need the ePaper font loader block. But once you have loaded the ePaper font loader block project to EEPROM, you have the fancy Serif, Script, and Bubble fonts to use. Here are the sizes available to each font:
The width of each character increases by 6 pixels from small (6 pixels wide) to medium (12 pixels wide) to large (18 pixels wide). The height increases by 8 pixels from small (8 pixels tall) to medium (16 pixels tall) to large (24 pixels tall). Because there is a 1 pixel spacer on the right and top of each character, the actual character size is 1 pixel less:
Now that you have loaded fonts to your Propeller board’s EEPROM, you are ready to experiment with those different fonts and sizes. By default, the ePaper print text block will use the Sans font in size small however you have other font and size options.
2.9" ePaper Font Display - Sans Blockly Code Example [1]
2.9" ePaper Font Display - Serif Blockly Code Example [2]
2.9" ePaper Font Display - Script Blockly Code Example [3]
2.9" ePaper Font Display - Bubble Blockly Code Example [4]
By default, the ePaper print text block will use black text on a white background. The ePaper font color block adds another element of fun and functionality!
Links
[1] https://learn.parallax.com/sites/default/files/content/AB-Blockly/Projects/ePaper/Project106697-ePaper-Font-Display-Sans.svg
[2] https://learn.parallax.com/sites/default/files/content/AB-Blockly/Projects/ePaper/Project106698-ePaper-Font-Display-Serif.svg
[3] https://learn.parallax.com/sites/default/files/content/AB-Blockly/Projects/ePaper/Project106700-ePaper-Font-Display-Script.svg
[4] https://learn.parallax.com/sites/default/files/content/AB-Blockly/Projects/ePaper/Project106701-ePaper-Font-Display-Bubble.svg