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Dependents: temp_hum IAC_send Smart_Home_sensors
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DHT
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Components
Revision 4:6937e130feca, committed 2016-05-28
- Comitter:
- sam_grove
- Date:
- Sat May 28 11:11:34 2016 +0000
- Parent:
- 2:df22ddf10d75
- Commit message:
- Remove warnings about implicit conversion from float to double and unify DHT11 and DHT22 init command sequence
Changed in this revision
| DHT.cpp | Show annotated file Show diff for this revision Revisions of this file |
diff -r df22ddf10d75 -r 6937e130feca DHT.cpp
--- 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()