doc: improve & complete documentation on many sensors

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/lcd/jhd1313m1.h

@@ -32,7 +32,14 @@ namespace upm {
  * @brief C++ API for Jhd1313m1 i2c controller for HD44780 based displays with
  * an RGB backlight such as the Grove RGB i2c LCD display
  *
+ * The Jhd1313m1 has two i2c addreses, one belongs to a controller very similar
+ * to the upm::Lcm1602 LCD driver which controls the HD44780 based display and the
+ * other controls solely the backlight. This module was tested with the Seed
+ * [Grove LCD RGB Backlight v2.0 display]
+ * (http://www.seeedstudio.com/depot/Grove-LCD-RGB-Backlight-p-1643.html?cPath=34_36)
+ *
  * @snippet rgb-lcd.cxx Interesting
+ * @image html grovergblcd.jpeg
  */
 class Jhd1313m1 : public I2CLcd {
     public:

src/lcd/lcm1602.h

@@ -37,9 +37,13 @@ namespace upm {
  *
  * This supports all sizes of HD44780 displays from 16x2 to 4x20, the
  * controller has no idea of the actual display hardware so will let you write
- * further than you can see
+ * further than you can see. These displays with such controllers are available
+ * from various manufacturers with different i2c addresses. The adafruit
+ * [TC1602A-01T](https://www.adafruit.com/datasheets/TC1602A-01T.pdf) seems to
+ * the best documented example.
  *
  * @snippet lcm-lcd.cxx Interesting
+ * @image html lcm1602.jpeg
  */
 class Lcm1602 : public I2CLcd {
     public:

src/lcd/ssd1308.h

@@ -148,7 +148,15 @@ typedef enum {
 /**
  * @brief C++ API for SSD1308 i2c controlled OLED displays
  *
- * @snippet lcm-lcd.cxx Interesting
+ * The [SSD1308](http://garden.seeedstudio.com/images/4/46/SSD1308_1.0.pdf) is
+ * a 128x64 Dot matrix OLED/PLED segment driver with controller. This
+ * implementation was tested using the
+ * [Grove LED 128×64 Display module]
+ * (http://www.seeedstudio.com/wiki/Grove_-_OLED_Display_0.96%22)
+ * which is an OLED monochrome display
+ *
+ * @snippet oled-1308.cxx Interesting
+ * @image html ssd1308.jpeg
  */
 class SSD1308 : public I2CLcd {
     public:

src/lcd/ssd1327.h

@@ -145,10 +145,23 @@ typedef enum {
     PAGE          =  2
 } displayAddressingMode;
 
+/**
+ * @brief C++ API for SSD1327 i2c controlled OLED displays
+ *
+ * The [SSD1327](http://garden.seeedstudio.com/images/8/82/SSD1327_datasheet.pdf)
+ * is a 96x96 Dot matrix OLED/PLED segment driver with controller. This
+ * implementation was tested using the
+ * [Grove LED 96×96 Display module]
+ * (http://www.seeedstudio.com/wiki/Grove_-_OLED_Display_1.12%22)
+ * which is an OLED monochrome display
+ *
+ * @snippet oled-1327.cxx Interesting
+ * @image html ssd1327.jpeg
+ */
 class SSD1327 : public I2CLcd {
     public:
         /**
-         * SSD1308 Constructor, calls libmraa initialisation functions
+         * SSD1327 Constructor, calls libmraa initialisation functions
          *
          * @param bus i2c bus to use
          * @param address the slave address the lcd is registered on