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document SPI and bitmap

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devsaurus 2015-03-11 22:20:28 +01:00
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README.md
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@ -346,24 +346,50 @@ The integration in nodemcu is developed for SSD1306 based display attached via t
U8glib v1.17
#####I2C connection
Hook up SDA and SCL to any free GPIOs. Eg. [lua_examples/graphics_test.lua](https://github.com/devsaurus/nodemcu-firmware/blob/dev/lua_examples/graphics_test.lua) expects SDA=5 (GPIO14) and SCL=6 (GPIO12). They are used to set up nodemcu's I2C driver before accessing the display:
Hook up SDA and SCL to any free GPIOs. Eg. `lua_examples/u8glib/graphics_test.lua` expects SDA=5 (GPIO14) and SCL=6 (GPIO12). They are used to set up nodemcu's I2C driver before accessing the display:
```lua
sda = 5
scl = 6
i2c.setup(0, sda, scl, i2c.SLOW)
```
#####SPI connection
The HSPI module is used, so certain pins are fixed:
* HSPI CLK = GPIO14
* HSPI MOSI = GPIO13
* HPSI MISO = GPIO12 (not used)
All other pins can be assigned to any available GPIO:
* CS
* D/C
* RES (optional)
Also refer to the initialization sequence eg in `lua_examples/u8glib/graphics_test.lua`:
```lua
spi.setup(1, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, spi.DATABITS_8, 0)
```
#####Library usage
The Lua bindings for this library closely follow u8glib's object oriented C++ API. Based on the u8g class, you create an object for your display type:
The Lua bindings for this library closely follow u8glib's object oriented C++ API. Based on the u8g class, you create an object for your display type.
SSD1306 via I2C:
```lua
sla = 0x3c
disp = u8g.ssd1306_128x64_i2c(sla)
```
SSD1306 via SPI:
```lua
cs = 8 -- GPIO15, pull-down 10k to GND
dc = 4 -- GPIO2
disp = u8g.ssd1306_128x64_spi(cs, dc)
```
This object provides all of u8glib's methods to control the display.
Again, refer to [lua_examples/graphics_test.lua](https://github.com/devsaurus/nodemcu-firmware/blob/dev/lua_examples/u8g_graphics_test.lua) to get an impression how this is achieved with Lua code. Visit the [u8glib homepage](https://code.google.com/p/u8glib/) for technical details.
Again, refer to `lua_examples/u8glib/graphics_test.lua` to get an impression how this is achieved with Lua code. Visit the [u8glib homepage](https://code.google.com/p/u8glib/) for technical details.
#####Fonts
u8glib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image, you'd need to include them in [app/include/user_config.h](https://github.com/devsaurus/nodemcu-firmware/blob/dev/app/include/user_config.h) and recompile. Simply add the desired fonts to the font table:
u8glib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image, you'd need to include them in `app/include/user_config.h` and recompile. Simply add the desired fonts to the font table:
```c
#define U8G_FONT_TABLE \
U8G_FONT_TABLE_ENTRY(font_6x10) \
@ -371,6 +397,9 @@ u8glib comes with a wide range of fonts for small displays. Since they need to b
```
They'll be available as `u8g.<font_name>` in Lua.
#####Bitmaps
Bitmaps and XBMs are supplied as strings to `drawBitmap()` and `drawXBM()`. This off-loads all data handling from the u8g module to generic methods for binary files. See `lua_examples/u8glib/u8g_bitmaps.lua`. Binary files can be uploaded with [nodemcu-uploader.py](https://github.com/kmpm/nodemcu-uploader).
#####Unimplemented functions
- [ ] Cursor handling
- [ ] disableCursor()
@ -379,12 +408,7 @@ They'll be available as `u8g.<font_name>` in Lua.
- [ ] setCursorFont()
- [ ] setCursorPos()
- [ ] setCursorStyle()
- [x] Bitmaps
- [x] drawBitmap()
- [x] drawXBM()
- [ ] General functions
- [x] begin()
- [ ] print()
- [ ] setContrast()
- [ ] setPrintPos()
- [ ] setHardwareBackup()