SoftwareBitBang bit slope bugfix (important) no more pulldown resisto…

…r :)

strategies/SoftwareBitBang/SoftwareBitBang.h

@@ -133,7 +133,7 @@ class SoftwareBitBang {

      uint16_t response = FAIL;
      uint32_t time = micros();
      /* Transmitter emits a bit SWBB_ACCEPTANCE / 4 long and tries
      /* Transmitter emits a bit SWBB_BIT_WIDTH / 4 long and tries
         to get a response cyclically for SWBB_TIMEOUT microseconds.
         Receiver synchronizes to the falling edge of the last incoming
         bit and transmits ACK or NAK */
@@ -144,6 +144,7 @@ class SoftwareBitBang {
          pinModeFast(_output_pin, OUTPUT);
          digitalWriteFast(_output_pin, HIGH);
          delayMicroseconds(SWBB_BIT_WIDTH / 4);
          digitalWriteFast(_output_pin, LOW); // Avoid 1 to 0 bit transition slope -\_
          pullDownFast(_output_pin);
        }
      }
@@ -186,10 +187,12 @@ class SoftwareBitBang {
    void send_response(uint8_t response) {
      pullDownFast(_input_pin);
      uint32_t time = micros();
      /* Transmitter emits a bit SWBB_ACCEPTANCE / 4 long and tries
      /* Transmitter emits a bit SWBB_BIT_WIDTH / 4 long and tries
         to get a response cyclically for SWBB_TIMEOUT microseconds.
         Receiver synchronizes to the falling edge of the last incoming
         bit and transmits ACK or NAK */
      while((uint32_t)(micros() - time) < (SWBB_BIT_WIDTH) && !digitalReadFast(_input_pin))
        time = micros(); // Wait for the last high ending
      while((uint32_t)(micros() - time) < (SWBB_BIT_WIDTH / 2.25) && digitalReadFast(_input_pin));
      pinModeFast(_output_pin, OUTPUT);
      send_byte(response);
@@ -203,6 +206,7 @@ class SoftwareBitBang {
      pinModeFast(_output_pin, OUTPUT);
      for(uint16_t b = 0; b < length; b++)
        send_byte(string[b]);
      digitalWriteFast(_output_pin, LOW); // Avoid 1 to 0 bit transition slope -\_
      pullDownFast(_output_pin);
    };