Merge pull request #4 from talbotmcinnis/DefaultPinForSwitchMultiPos

Default pin for switch multi pos

Author: talbotmcinnis

releasenotes.md

@@ -1,3 +1,11 @@
+## v0.3.2
+- Added new feature for SwitchMultiPos, allowing a "default" state to be specified for controls that can have a default state.  For example, A-10 Emergency Trim without a center detent
+```c++
+// Center pos is not connected, so define PIN_NC so that it will return to center when no other pin is active
+const byte efcpEmerTrimPins[5] = {DcsBios::PIN_NC, 2, 1, 3, 0};
+DcsBios::SwitchMultiPos efcpEmerTrim("EFCP_EMER_TRIM", efcpEmerTrimPins, 5);
+```
+
 ## v0.3.1
 
 - Fix AnalogMultiPos as per [Analog Multipos does not send commands (github.com)](https://github.com/talbotmcinnis/dcs-bios-arduino-library/issues/2)

src/DcsBios.h

@@ -25,6 +25,10 @@
 #define PRR0 PRR
 #endif
 
+namespace DcsBios {
+	const unsigned char PIN_NC = 0xFF;
+}
+
 /*
 The following is an ugly hack to work with the Arduino IDE's build system.
 The DCS-BIOS Arduino Library is configured with #defines such as DCSBIOS_RS485_MASTER or DCSBIOS_RS485_SLAVE <address>.

src/internal/Switches.h

@@ -140,12 +140,17 @@ namespace DcsBios {
 		char lastState_;
 		bool reverse_;
 		char readState() {
-			unsigned char i;
-			for (i=0; i<numberOfPins_; i++) {
-				if (digitalRead(pins_[i]) == LOW && reverse_ == false) return i;
-				else if (digitalRead(pins_[i]) == HIGH && reverse_ == true) return i;
+			unsigned char ncPinIdx = lastState_;
+			for (unsigned char i=0; i<numberOfPins_; i++) {
+				if( pins_[i] == PIN_NC)
+					ncPinIdx = i;
+				else
+				{
+					if (digitalRead(pins_[i]) == LOW && reverse_ == false) return i;
+					else if (digitalRead(pins_[i]) == HIGH && reverse_ == true) return i;
+				}
 			}
-			return lastState_;
+			return ncPinIdx;
 		}
 		void resetState()
 		{
@@ -172,7 +177,8 @@ namespace DcsBios {
 			numberOfPins_ = numberOfPins;
 			unsigned char i;
 			for (i=0; i<numberOfPins; i++) {
-				pinMode(pins[i], INPUT_PULLUP);
+				if( pins[i] != PIN_NC)
+					pinMode(pins[i], INPUT_PULLUP);
 			}
 			lastState_ = readState();
 		}