Ian Molesworth
Sensiron SHT 7x Temperature and humidity device library
Dependents: temp xj-Nucleo-F303K8-SHT75-TEST
Revision 1:20aa2d4a28bf, committed 2010-10-27
- Comitter:
- nimbusgb
- Date:
- Wed Oct 27 15:51:27 2010 +0000
- Parent:
- 0:f401474a3e96
- Child:
- 2:dd218144f9fe
- Commit message:
Changed in this revision
--- a/sht75.cpp Wed Oct 27 15:27:38 2010 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,180 +0,0 @@
-//
-// Ian Molesworth October 2010
-// SHT 75 class
-//
-//
-// To do:
-//
-//
-
-#include "sht75.h"
-
-void SHT75::reset()
- {
- _data.output();
- _data = 1; // data bus high
- for (int i=0;i<12;i++)
- {
- _clock = 1; // clock high
- wait_us(1);
- _clock = 0; // clock lo
- wait_us(1);
- }
- _clock = 1; // clock high
- wait_us(1);
- _data = 0;
- wait_us(1);
- _clock = 0; // clock lo
- wait_us(1);
- _clock = 1;
- wait_us(1);
- _data = 1;
- wait_us(1);
- _clock = 0;
- wait_us(1);
- }
-
-void SHT75::softReset(void)
- {
- _data.output();
- start();
- write(0x1E);
- wait_ms(12);
- }
-
-void SHT75::start(void)
- {
- _data.output();
- _clock = 1;
- wait_us(1);
- _data = 0;
- wait_us(1);
- _clock = 0;
- wait_us(1);
- _clock = 1;
- wait_us(1);
- _data = 1;
- wait_us(1);
- _clock = 0;
- }
-
-int SHT75::readStatus(void)
- {
- int status;
- status = -1;
- start();
- if (write(0x06) == 0)
- status = read(1); // read with a wait for ack
- read(0); // read without the wait
- return status;
- }
-
-bool SHT75::write(char d)
- {
- auto int i;
- _data.output(); // bus output
- // Writes char and returns -1 if no ACK was sent from remote
- for (i=0;i<8;i++)
- {
- if (d & 0x80)
- _data = 1; // data high
- else
- _data = 0; // data lo
- // shift the data
- d <<= 1;
- wait_us(1);
- _clock = 1; // clock high
- wait_us(1);
- _clock = 0; // clock lo
- }
- _data.input(); // float the bus
- wait_us(1);
- _clock = 1; // clock high
- wait_us(1);
- i = _data;
- _clock = 0; // clock lo
- return i; // leave the bus in input mode and return the status of the ack bit read.
- }
-
-int SHT75::read(char ack)
- {
- auto int i,s;
- auto char c;
- s = 0;
- _data.input(); // bus to input
-
- for (i=0;i<8;i++)
- {
- s <<= 1;
- wait_us(1);
- _clock = 1; // clock high
- wait_us(1);
- c = _data; // get the data bit
- _clock = 0; // clock lo
- if ( c )
- s |= 1;
- }
-
- if (ack == 1)
- _data = 0; // data lo
- else
- _data = 1; // data hi
- _data.output();
- _clock = 1; // clock lo
- wait_us(1);
- _clock = 0; // clock lo
- _data = 1; // data hi
- _data.input();
- return s;
- }
-
-
-// Put the current temperature into passed variable
-bool SHT75::readTempTicks(int* temp)
-{
- int v, value;
- start(); // Start a tx ( leaves data as input )
- if (write(0x03) == 0) // send the read command and get an ack
- {
- for (v=0; v<50; v ++) // wait for ready up to 500 ms
- {
- wait_ms(10); // 10 ms pause
- if ( _data == 0 ) //
- {
- value = read(1); // read a byte
- value <<= 8; // shift it in
- value |= read(1); // read another byte
- read(0);
- // transfer the value
- *temp = value;
- reset();
- return true;
- }
- }
- }
- return false;
- }
-
-bool SHT75::readHumidityTicks(int* humi)
- {
- start();
- if (write(0x05) == 0)
- {
- for (int value=0; value<50; value ++) // wait for ready up to 500 ms
- {
- wait_ms(10); //
- if ( _data == 0 ) //
- {
- value = read(1);
- value <<= 8;
- value |= read(1);
- read(0);
- *humi = value; // transfer the value
- reset();
- return true;
- }
- }
- }
-
- return false;
- }
--- a/sht75.h Wed Oct 27 15:27:38 2010 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,75 +0,0 @@
-/* mbed Sensiron SHT7x temperature and humidity sensor library
-*
-* Sensiron data at http://www.sensirion.com/en/01_humidity_sensors/06_humidity_sensor_sht75.htm
-*
-* Copyright (c) Ian Molesworth October 2010
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to use
-* copy or modify the software for private or non-commercial purposes only.
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-*
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-*/
-
-
-#ifndef SHT75_H
-#define SHT75_H
-
-#include "mbed.h"
-
-const float C1= -4.0; // for 12 Bit humi
-const float C2= +0.0405; // for 12 Bit humi
-const float C3= -0.0000028; // for 12 Bit hum
-const float TL= -39.61; // 3v 14 bit
-const float T1= +0.01; // for 14 Bit @ 5V
-const float T2= +0.00008; // for 14 Bit @ 5V
-
-class SHT75
- {
- public:
- /** Create an SHT object connected to the specified Digital pins
- *
- * @param pclock digital pin to use as clock
- * @param pdata digital pin to use as data bus ( bidirectional )
- */
- SHT75(PinName pclock, PinName pdata): _clock(pclock), _data(pdata) {};
- /** read the temperature ticks value 14 bit resolution
- *
- * @param int *temp pointer to an integer to hold the tick value
- * @returns boolean true if read acknowledges
- */
- bool readTempTicks(int* temp);
- /** read the humidity ticks value 12 bit resolution
- *
- * @param int *temp pointer to an integer to hold the tick value
- * @returns boolean true if read acknowledges
- */
- bool readHumidityTicks(int* temp);
- /** start up reset
- *
- * call to resync or abort current operation.
- * worth calling every now and then to make sure your system is not hung.
- */
- void reset(void);
- void softReset(void);
- int readStatus(void);
-
- private:
- DigitalInOut _data;
- DigitalOut _clock;
-
- void start(void);
- int read(char);
- bool write(char);
- };
-
-#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sht7X.cpp Wed Oct 27 15:51:27 2010 +0000
@@ -0,0 +1,180 @@
+//
+// Ian Molesworth October 2010
+// SHT 75 class
+//
+//
+// To do:
+//
+//
+
+#include "sht7X.h"
+
+void SHT75::reset()
+ {
+ _data.output();
+ _data = 1; // data bus high
+ for (int i=0;i<12;i++)
+ {
+ _clock = 1; // clock high
+ wait_us(1);
+ _clock = 0; // clock lo
+ wait_us(1);
+ }
+ _clock = 1; // clock high
+ wait_us(1);
+ _data = 0;
+ wait_us(1);
+ _clock = 0; // clock lo
+ wait_us(1);
+ _clock = 1;
+ wait_us(1);
+ _data = 1;
+ wait_us(1);
+ _clock = 0;
+ wait_us(1);
+ }
+
+void SHT75::softReset(void)
+ {
+ _data.output();
+ start();
+ write(0x1E);
+ wait_ms(12);
+ }
+
+void SHT75::start(void)
+ {
+ _data.output();
+ _clock = 1;
+ wait_us(1);
+ _data = 0;
+ wait_us(1);
+ _clock = 0;
+ wait_us(1);
+ _clock = 1;
+ wait_us(1);
+ _data = 1;
+ wait_us(1);
+ _clock = 0;
+ }
+
+int SHT75::readStatus(void)
+ {
+ int status;
+ status = -1;
+ start();
+ if (write(0x06) == 0)
+ status = read(1); // read with a wait for ack
+ read(0); // read without the wait
+ return status;
+ }
+
+bool SHT75::write(char d)
+ {
+ auto int i;
+ _data.output(); // bus output
+ // Writes char and returns -1 if no ACK was sent from remote
+ for (i=0;i<8;i++)
+ {
+ if (d & 0x80)
+ _data = 1; // data high
+ else
+ _data = 0; // data lo
+ // shift the data
+ d <<= 1;
+ wait_us(1);
+ _clock = 1; // clock high
+ wait_us(1);
+ _clock = 0; // clock lo
+ }
+ _data.input(); // float the bus
+ wait_us(1);
+ _clock = 1; // clock high
+ wait_us(1);
+ i = _data;
+ _clock = 0; // clock lo
+ return i; // leave the bus in input mode and return the status of the ack bit read.
+ }
+
+int SHT75::read(char ack)
+ {
+ auto int i,s;
+ auto char c;
+ s = 0;
+ _data.input(); // bus to input
+
+ for (i=0;i<8;i++)
+ {
+ s <<= 1;
+ wait_us(1);
+ _clock = 1; // clock high
+ wait_us(1);
+ c = _data; // get the data bit
+ _clock = 0; // clock lo
+ if ( c )
+ s |= 1;
+ }
+
+ if (ack == 1)
+ _data = 0; // data lo
+ else
+ _data = 1; // data hi
+ _data.output();
+ _clock = 1; // clock lo
+ wait_us(1);
+ _clock = 0; // clock lo
+ _data = 1; // data hi
+ _data.input();
+ return s;
+ }
+
+
+// Put the current temperature into passed variable
+bool SHT75::readTempTicks(int* temp)
+{
+ int v, value;
+ start(); // Start a tx ( leaves data as input )
+ if (write(0x03) == 0) // send the read command and get an ack
+ {
+ for (v=0; v<50; v ++) // wait for ready up to 500 ms
+ {
+ wait_ms(10); // 10 ms pause
+ if ( _data == 0 ) //
+ {
+ value = read(1); // read a byte
+ value <<= 8; // shift it in
+ value |= read(1); // read another byte
+ read(0);
+ // transfer the value
+ *temp = value;
+ reset();
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+bool SHT75::readHumidityTicks(int* humi)
+ {
+ start();
+ if (write(0x05) == 0)
+ {
+ for (int value=0; value<50; value ++) // wait for ready up to 500 ms
+ {
+ wait_ms(10); //
+ if ( _data == 0 ) //
+ {
+ value = read(1);
+ value <<= 8;
+ value |= read(1);
+ read(0);
+ *humi = value; // transfer the value
+ reset();
+ return true;
+ }
+ }
+ }
+
+ return false;
+ }
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sht7X.h Wed Oct 27 15:51:27 2010 +0000
@@ -0,0 +1,100 @@
+/* mbed Sensiron SHT7x temperature and humidity sensor library
+*
+* Sensiron data at http://www.sensirion.com/en/01_humidity_sensors/06_humidity_sensor_sht75.htm
+*
+* Copyright (c) Ian Molesworth October 2010
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to use
+* copy or modify the software for private or non-commercial purposes only.
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+*/
+
+
+#ifndef SHT75_H
+#define SHT75_H
+
+#include "mbed.h"
+
+const float C1= -4.0; // for 12 Bit humi
+const float C2= +0.0405; // for 12 Bit humi
+const float C3= -0.0000028; // for 12 Bit hum
+const float TL= -39.61; // 3v 14 bit
+const float T1= +0.01; // for 14 Bit @ 5V
+const float T2= +0.00008; // for 14 Bit @ 5V
+
+/** SHT7x class
+*
+* Example:
+* @code
+* //initialise the device read temperature ticks, read humidity ticks and then
+* calculate the liniarised humidity value.
+* #include "mbed.h"
+* #include "SHT7X.h"
+00035 *
+00036 * Servo myservo(p21);
+00037 *
+00038 * int main() {
+00039 * while(1) {
+00040 * for(int i=0; i<100; i++) {
+00041 * myservo = i/100.0;
+00042 * wait(0.01);
+00043 * }
+00044 * for(int i=100; i>0; i--) {
+00045 * myservo = i/100.0;
+00046 * wait(0.01);
+00047 * }
+00048 * }
+00049 * }
+00050 * @endcode
+00051 */
+class SHT75
+ {
+ public:
+ /** Create an SHT object connected to the specified Digital pins
+ *
+ * @param pclock digital pin to use as clock
+ * @param pdata digital pin to use as data bus ( bidirectional )
+ */
+ SHT75(PinName pclock, PinName pdata): _clock(pclock), _data(pdata) {};
+ /** read the temperature ticks value 14 bit resolution
+ *
+ * @param int *temp pointer to an integer to hold the tick value
+ * @returns boolean true if read acknowledges
+ */
+ bool readTempTicks(int* temp);
+ /** read the humidity ticks value 12 bit resolution
+ *
+ * @param int *temp pointer to an integer to hold the tick value
+ * @returns boolean true if read acknowledges
+ */
+ bool readHumidityTicks(int* temp);
+ /** start up reset
+ *
+ * call to resync or abort current operation.
+ * worth calling every now and then to make sure your system is not hung.
+ */
+ void reset(void);
+ void softReset(void);
+ int readStatus(void);
+
+ private:
+ DigitalInOut _data;
+ DigitalOut _clock;
+
+ void start(void);
+ int read(char);
+ bool write(char);
+ };
+
+#endif