Revision 3:6937e130feca, committed 2016-05-28

Comitter:

sam_grove

Date:

Sat May 28 11:11:34 2016 +0000

Parent:

2:df22ddf10d75

Child:

4:1b4e37ce64f8

Commit message:

Remove warnings about implicit conversion from float to double and unify DHT11 and DHT22 init command sequence

Changed in this revision

--- a/DHT.cpp	Fri Aug 15 20:55:43 2014 +0000
+++ b/DHT.cpp	Sat May 28 11:11:34 2016 +0000
@@ -77,13 +77,12 @@
     // start the transfer
     DHT_io.output();
     DHT_io = 0;
-    // only 500uS for DHT22 but 18ms for DHT11
-    (_DHTtype == 11) ? wait_ms(18) : wait(1);
+    wait_ms(18);
     DHT_io = 1;
     wait_us(30);
     DHT_io.input();
     // wait till the sensor grabs the bus
-    if (ERROR_NONE != stall(DHT_io, 1, 40)) {
+    if (ERROR_NONE != stall(DHT_io, 1, 100)) {
         return ERROR_NOT_PRESENT;
     }
     // sensor should signal low 80us and then hi 80us
@@ -166,22 +165,22 @@
 
 float DHT::ConvertCelciustoKelvin(float const celsius)
 {
-    return celsius + 273.15;
+    return celsius + 273.15f;
 }
 
 // dewPoint function NOAA
 // reference: http://wahiduddin.net/calc/density_algorithms.htm
 float DHT::CalcdewPoint(float const celsius, float const humidity)
 {
-    float A0= 373.15/(273.15 + celsius);
+    float A0= 373.15f/(273.15f + celsius);
     float SUM = -7.90298 * (A0-1);
-    SUM += 5.02808 * log10(A0);
-    SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ;
+    SUM += 5.02808f * log10(A0);
+    SUM += -1.3816e-7 * (pow(10, (11.344f*(1-1/A0)))-1) ;
     SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ;
     SUM += log10(1013.246);
     float VP = pow(10, SUM-3) * humidity;
-    float T = log(VP/0.61078);   // temp var
-    return (241.88 * T) / (17.558-T);
+    float T = log(VP/0.61078f);   // temp var
+    return (241.88f * T) / (17.558f-T);
 }
 
 // delta max = 0.6544 wrt dewPoint()