add a check to ensure encoder mode is supported

Author: Richard Unger

src/encoders/stm32hwencoder/STM32HWEncoder.cpp

@@ -29,6 +29,10 @@ int STM32HWEncoder::hasIndex() { return 0; }
 void STM32HWEncoder::init() {
     // GPIO configuration
     TIM_TypeDef *InstanceA = (TIM_TypeDef *)pinmap_peripheral(_pinA, PinMap_TIM);
+    if (!IS_TIM_ENCODER_INTERFACE_INSTANCE(InstanceA)) {
+        initialized = false;
+        return;
+    }
     TIM_TypeDef *InstanceB = (TIM_TypeDef *)pinmap_peripheral(_pinB, PinMap_TIM);
     if (InstanceA != InstanceB) {
         initialized = false;
@@ -37,6 +41,9 @@ void STM32HWEncoder::init() {
     pinmap_pinout(_pinA, PinMap_TIM);
     pinmap_pinout(_pinB, PinMap_TIM);
 
+    // TODO check width:
+    //IS_TIM_32B_COUNTER_INSTANCE(InstanceA);
+
     // set up timer for encoder
     encoder_handle.Init.Period = cpr - 1;
     encoder_handle.Init.Prescaler = 0;