From ceb423c007c42203993662d0b06924801e4462e7 Mon Sep 17 00:00:00 2001
From: bg- <bg->
Date: Mon, 28 May 2007 16:24:58 +0000
Subject: [PATCH] * Add sht11_off.

---
 platform/sky/dev/sht11.c | 29 +++++++++++++++++++++++++----
 platform/sky/dev/sht11.h | 13 ++++++++++++-
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/platform/sky/dev/sht11.c b/platform/sky/dev/sht11.c
index eb4481588..1691c7c3f 100644
--- a/platform/sky/dev/sht11.c
+++ b/platform/sky/dev/sht11.c
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
  * SUCH DAMAGE. 
  *
- * @(#)$Id: sht11.c,v 1.1 2007/04/04 12:48:50 bg- Exp $
+ * @(#)$Id: sht11.c,v 1.2 2007/05/28 16:25:29 bg- Exp $
  */
 
 /*
@@ -194,6 +194,10 @@ crc8_add(unsigned acc, unsigned byte)
 }
 #endif /* CRC_CHECK */
 
+/*
+ * Power up the device. The device can be used after an additional
+ * 11ms waiting time.
+ */
 void
 sht11_init(void)
 {
@@ -207,6 +211,17 @@ sht11_init(void)
   P1DIR |= BV(PWR) | BV(SCL);
 }
 
+/*
+ * Power of device.
+ */
+void
+sht11_off(void)
+{
+  P1OUT &= ~BV(PWR);
+  P1OUT &= ~(BV(SDA) | BV(SCL));
+  P1DIR |= BV(PWR) | BV(SCL);
+}
+
 /*
  * Only commands MEASURE_HUMI or MEASURE_TEMP!
  */
@@ -246,12 +261,18 @@ scmd(unsigned cmd)
   return -1;
 }
 
+/*
+ * Call may take up to 210ms.
+ */
 unsigned
 sht11_temp(void)
 {
   return scmd(MEASURE_TEMP);
 }
 
+/*
+ * Call may take up to 210ms.
+ */
 unsigned
 sht11_humidity(void)
 {
@@ -260,7 +281,7 @@ sht11_humidity(void)
 
 #if 0 /* But ok! */
 unsigned
-sget_sreg(void)
+sht11_sreg(void)
 {
   unsigned sreg, rcrc;
 
@@ -290,8 +311,8 @@ sget_sreg(void)
 #endif
 
 #if 0
-unsigned
-sset_sreg(unsigned sreg)
+int
+sht11_set_sreg(unsigned sreg)
 {
   sstart();			/* Start transmission */
   if (!swrite(STATUS_REG_W))
diff --git a/platform/sky/dev/sht11.h b/platform/sky/dev/sht11.h
index 5d0dec87e..7231dc0dc 100644
--- a/platform/sky/dev/sht11.h
+++ b/platform/sky/dev/sht11.h
@@ -26,15 +26,26 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
  * SUCH DAMAGE. 
  *
- * @(#)$Id: sht11.h,v 1.1 2007/04/04 12:48:50 bg- Exp $
+ * @(#)$Id: sht11.h,v 1.2 2007/05/28 16:24:58 bg- Exp $
  */
 
 #ifndef SHT11_H
 #define SHT11_H
 
 void sht11_init(void);
+void sht11_off(void);
 
 unsigned sht11_temp(void);
 unsigned sht11_humidity(void);
+unsigned sht11_sreg(void);
+int      sht11_set_sreg(unsigned);
+
+/*
+ * Relative Humidity in percent (h in 12 bits resolution)
+ * RH = -4 + 0.0405*h - 2.8e-6*(h*h)
+ *
+ * Temperature in Celsius (t in 14 bits resolution at 3 Volts)
+ * T = -39.60 + 0.01*t
+ */
 
 #endif /* SHT11_H */