Adding variants for other boards.

Author: Nathan Seidle

libraries/Examples/examples/Advanced/Differential_ADC/Differential_ADC.ino

@@ -11,6 +11,11 @@
   A differential ADC port measures -1.0V to 1.0V with
   0 = -1.0V, 8192 = 0V, and 16383 = 1.0V when the ADC is in 14-bit mode.
 
+  Using a trimpot, attach DIFF- to GND and DIFF+ to the center pin of the trimpot.
+  Connect the outer pins of the trimpot to 3.3V and GND.
+  Twisting the trimpot you should see the voltage change from 0 to 1.0V.
+  Switching DIFF-/+ you should see -1.0V to 0V.
+
   SparkFun labored with love to create this code. Feel like supporting open source hardware?
   Buy a board from SparkFun! https://www.sparkfun.com/products/15376
 */

variants/artemis_thing_plus/config/variant.cpp

@@ -70,3 +70,4 @@ const ap3_gpio_pin_t ap3_analog_A4 = 23;
 const ap3_gpio_pin_t ap3_analog_A5 = 24;
 const ap3_gpio_pin_t ap3_analog_A6 = 3;
 const ap3_gpio_pin_t ap3_analog_A7 = 9;
+const ap3_gpio_pin_t ap3_analog_DIFF0 = AP3_ADC_DIFF0_PAD;

variants/artemis_thing_plus/config/variant.h

@@ -57,6 +57,7 @@ extern Uart Serial1;
 #define A5 ap3_analog_A5
 #define A6 ap3_analog_A6
 #define A7 ap3_analog_A7
+#define ADIFF0 ap3_analog_DIFF0
 
 // Promise the existence of analog pin names
 extern const ap3_gpio_pin_t ap3_analog_A0;
@@ -67,6 +68,7 @@ extern const ap3_gpio_pin_t ap3_analog_A4;
 extern const ap3_gpio_pin_t ap3_analog_A5;
 extern const ap3_gpio_pin_t ap3_analog_A6;
 extern const ap3_gpio_pin_t ap3_analog_A7;
+extern const ap3_gpio_pin_t ap3_analog_DIFF0;
 
 #define LED_BUILTIN 18
 

variants/redboard_artemis_atp/config/variant.cpp

@@ -92,3 +92,5 @@ extern const ap3_gpio_pin_t ap3_analog_A12 = 12;
 extern const ap3_gpio_pin_t ap3_analog_A32 = 32;
 extern const ap3_gpio_pin_t ap3_analog_A33 = 33;
 extern const ap3_gpio_pin_t ap3_analog_A35 = 35;
+extern const ap3_gpio_pin_t ap3_analog_DIFF0 = AP3_ADC_DIFF0_PAD;
+extern const ap3_gpio_pin_t ap3_analog_DIFF1 = AP3_ADC_DIFF1_PAD;

variants/redboard_artemis_atp/config/variant.h

@@ -58,6 +58,8 @@ extern Uart Serial1;
 #define A32 ap3_analog_A32
 #define A33 ap3_analog_A33
 #define A35 ap3_analog_A35
+#define ADIFF0 ap3_analog_DIFF0
+#define ADIFF1 ap3_analog_DIFF1
 
 // Promise the existence of analog pin names
 extern const ap3_gpio_pin_t ap3_analog_A29;
@@ -70,6 +72,8 @@ extern const ap3_gpio_pin_t ap3_analog_A12;
 extern const ap3_gpio_pin_t ap3_analog_A32;
 extern const ap3_gpio_pin_t ap3_analog_A33;
 extern const ap3_gpio_pin_t ap3_analog_A35;
+extern const ap3_gpio_pin_t ap3_analog_DIFF0;
+extern const ap3_gpio_pin_t ap3_analog_DIFF1;
 
 #define LED_BUILTIN 5
 

variants/redboard_artemis_nano/config/variant.cpp

@@ -65,3 +65,4 @@ const ap3_gpio_pin_t ap3_analog_A5 = 5;
 const ap3_gpio_pin_t ap3_analog_A14 = 14;
 const ap3_gpio_pin_t ap3_analog_A15 = 15;
 const ap3_gpio_pin_t ap3_analog_A16 = 16;
+const ap3_gpio_pin_t ap3_analog_DIFF0 = AP3_ADC_DIFF0_PAD;

variants/redboard_artemis_nano/config/variant.h

@@ -56,6 +56,7 @@ extern Uart Serial1;
 #define A14 ap3_analog_A14
 #define A15 ap3_analog_A15
 #define A16 ap3_analog_A16
+#define ADIFF0 ap3_analog_DIFF0
 
 // Promise the existence of analog pin names
 extern const ap3_gpio_pin_t ap3_analog_A0;
@@ -66,6 +67,7 @@ extern const ap3_gpio_pin_t ap3_analog_A5;
 extern const ap3_gpio_pin_t ap3_analog_A14;
 extern const ap3_gpio_pin_t ap3_analog_A15;
 extern const ap3_gpio_pin_t ap3_analog_A16;
+extern const ap3_gpio_pin_t ap3_analog_DIFF0;
 
 #define LED_BUILTIN 19