drv_ds1820_simple.c - fixed onewire protocol

 * Do not use HAL_PIN_SetOutputValue() when reading sensor response - output must be open-drain.
 * Use Input_Pullup when reading sensor response instead. That allows to connect sensor w/o adding pullup resistor.
 * Fixed OWReadBit timing, read must be done within 15us, instead of after. Closes: #1582

Author: rpv-tomsk

src/driver/drv_ds1820_simple.c

@@ -69,9 +69,8 @@ static int OWReset(int Pin)
 	HAL_PIN_Setup_Output(Pin);
 	HAL_PIN_SetOutputValue(Pin, 0); // Drives DQ low
 	HAL_Delay_us(OWtimeH);
-	HAL_PIN_SetOutputValue(Pin, 1); // Releases the bus
+	HAL_PIN_Setup_Input_Pullup(Pin);  // Releases the bus
 	HAL_Delay_us(OWtimeI);
-	HAL_PIN_Setup_Input_Pullup(Pin);
 	result = HAL_PIN_ReadDigitalInput(Pin) ^ 0x01; // Sample for presence pulse from slave
 
 	xTaskResumeAll();
@@ -118,11 +117,11 @@ static int OWReadBit(int Pin)
 
 	noInterrupts();
 	HAL_PIN_Setup_Output(Pin);
-	HAL_PIN_SetOutputValue(Pin, 0); // Drives DQ low
-	HAL_Delay_us(OWtimeA);
-	HAL_PIN_SetOutputValue(Pin, 1); // Releases the bus
-	HAL_Delay_us(OWtimeE);
-	HAL_PIN_Setup_Input_Pullup(Pin);
+	HAL_PIN_SetOutputValue(Pin, 0);  // Drives DQ low
+	HAL_Delay_us(1);                 // give sensor time to react on start pulse
+	HAL_PIN_Setup_Input_Pullup(Pin); // Release the bus
+	HAL_Delay_us(OWtimeE);           // give time for bus rise, if not pulled
+
 	result = HAL_PIN_ReadDigitalInput(Pin); // Sample for presence pulse from slave
 	interrupts();	// hope for the best for the following timer and keep CRITICAL as short as possible
 	HAL_Delay_us(OWtimeF); // Complete the time slot and 10us recovery