WiringPi: Bring back all of the stuffs I removed to do with peripherals
Imported from the official WiringPi repository, version 2.60.
Signed-off-by: Deokgyu Yang <secugyu@gmail.com>
Change-Id: I82dc00ab9f038f9bc4c6a9c4ca3affe5a5d33ae1
diff --git a/devLib/maxdetect.c b/devLib/maxdetect.c
new file mode 100644
index 0000000..74ff70e
--- /dev/null
+++ b/devLib/maxdetect.c
@@ -0,0 +1,238 @@
+/*
+ * maxdetect.c:
+ * Driver for the MaxDetect series sensors
+ *
+ * Copyright (c) 2013 Gordon Henderson.
+ ***********************************************************************
+ * This file is part of wiringPi:
+ * https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ * wiringPi is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * wiringPi is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <sys/time.h>
+#include <stdio.h>
+//#include <stdlib.h>
+//#include <unistd.h>
+
+#include <wiringPi.h>
+
+#include "maxdetect.h"
+
+#ifndef TRUE
+# define TRUE (1==1)
+# define FALSE (1==2)
+#endif
+
+
+/*
+ * maxDetectLowHighWait:
+ * Wait for a transition from low to high on the bus
+ *********************************************************************************
+ */
+
+static int maxDetectLowHighWait (const int pin)
+{
+ struct timeval now, timeOut, timeUp ;
+
+// If already high then wait for pin to go low
+
+ gettimeofday (&now, NULL) ;
+ timerclear (&timeOut) ;
+ timeOut.tv_usec = 1000 ;
+ timeradd (&now, &timeOut, &timeUp) ;
+
+ while (digitalRead (pin) == HIGH)
+ {
+ gettimeofday (&now, NULL) ;
+ if (timercmp (&now, &timeUp, >))
+ return FALSE ;
+ }
+
+// Wait for it to go HIGH
+
+ gettimeofday (&now, NULL) ;
+ timerclear (&timeOut) ;
+ timeOut.tv_usec = 1000 ;
+ timeradd (&now, &timeOut, &timeUp) ;
+
+ while (digitalRead (pin) == LOW)
+ {
+ gettimeofday (&now, NULL) ;
+ if (timercmp (&now, &timeUp, >))
+ return FALSE ;
+ }
+
+ return TRUE ;
+}
+
+
+/*
+ * maxDetectClockByte:
+ * Read in a single byte from the MaxDetect bus
+ *********************************************************************************
+ */
+
+static unsigned int maxDetectClockByte (const int pin)
+{
+ unsigned int byte = 0 ;
+ int bit ;
+
+ for (bit = 0 ; bit < 8 ; ++bit)
+ {
+ if (!maxDetectLowHighWait (pin))
+ return 0 ;
+
+// bit starting now - we need to time it.
+
+ delayMicroseconds (30) ;
+ byte <<= 1 ;
+ if (digitalRead (pin) == HIGH) // It's a 1
+ byte |= 1 ;
+ }
+
+ return byte ;
+}
+
+
+/*
+ * maxDetectRead:
+ * Read in and return the 4 data bytes from the MaxDetect sensor.
+ * Return TRUE/FALSE depending on the checksum validity
+ *********************************************************************************
+ */
+
+int maxDetectRead (const int pin, unsigned char buffer [4])
+{
+ int i ;
+ unsigned int checksum ;
+ unsigned char localBuf [5] ;
+ struct timeval now, then, took ;
+
+// See how long we took
+
+ gettimeofday (&then, NULL) ;
+
+// Wake up the RHT03 by pulling the data line low, then high
+// Low for 10mS, high for 40uS.
+
+ pinMode (pin, OUTPUT) ;
+ digitalWrite (pin, 0) ; delay (10) ;
+ digitalWrite (pin, 1) ; delayMicroseconds (40) ;
+ pinMode (pin, INPUT) ;
+
+// Now wait for sensor to pull pin low
+
+ if (!maxDetectLowHighWait (pin))
+ return FALSE ;
+
+// and read in 5 bytes (40 bits)
+
+ for (i = 0 ; i < 5 ; ++i)
+ localBuf [i] = maxDetectClockByte (pin) ;
+
+ checksum = 0 ;
+ for (i = 0 ; i < 4 ; ++i)
+ {
+ buffer [i] = localBuf [i] ;
+ checksum += localBuf [i] ;
+ }
+ checksum &= 0xFF ;
+
+// See how long we took
+
+ gettimeofday (&now, NULL) ;
+ timersub (&now, &then, &took) ;
+
+// Total time to do this should be:
+// 10mS + 40µS - reset
+// + 80µS + 80µS - sensor doing its low -> high thing
+// + 40 * (50µS + 27µS (0) or 70µS (1) )
+// = 15010µS
+// so if we take more than that, we've had a scheduling interruption and the
+// reading is probably bogus.
+
+ if ((took.tv_sec != 0) || (took.tv_usec > 16000))
+ return FALSE ;
+
+ return checksum == localBuf [4] ;
+}
+
+
+/*
+ * readRHT03:
+ * Read the Temperature & Humidity from an RHT03 sensor
+ * Values returned are *10, so 123 is 12.3.
+ *********************************************************************************
+ */
+
+int readRHT03 (const int pin, int *temp, int *rh)
+{
+ static struct timeval then ; // will initialise to zero
+ static int lastTemp = 0 ;
+ static int lastRh = 0 ;
+
+ int result ;
+ struct timeval now, timeOut ;
+ unsigned char buffer [4] ;
+
+// The data sheets say to not read more than once every 2 seconds, so you
+// get the last good reading
+
+ gettimeofday (&now, NULL) ;
+ if (timercmp (&now, &then, <))
+ {
+ *rh = lastRh ;
+ *temp = lastTemp ;
+ return TRUE ;
+ }
+
+// Set timeout for next read
+
+ gettimeofday (&now, NULL) ;
+ timerclear (&timeOut) ;
+ timeOut.tv_sec = 2 ;
+ timeradd (&now, &timeOut, &then) ;
+
+// Read ...
+
+ result = maxDetectRead (pin, buffer) ;
+
+ if (!result) // Try again, but just once
+ result = maxDetectRead (pin, buffer) ;
+
+ if (!result)
+ return FALSE ;
+
+ *rh = (buffer [0] * 256 + buffer [1]) ;
+ *temp = (buffer [2] * 256 + buffer [3]) ;
+
+ if ((*temp & 0x8000) != 0) // Negative
+ {
+ *temp &= 0x7FFF ;
+ *temp = -*temp ;
+ }
+
+// Discard obviously bogus readings - the checksum can't detect a 2-bit error
+// (which does seem to happen - no realtime here)
+
+ if ((*rh > 999) || (*temp > 800) || (*temp < -400))
+ return FALSE ;
+
+ lastRh = *rh ;
+ lastTemp = *temp ;
+
+ return TRUE ;
+}