28018 Parallax Inc, 28018 Datasheet - Page 8

• Manufacturer Part Number: 28018
• Description: MODULE SENSOR TEMP+HUMIDITY
• Manufacturer: Parallax Inc
• Series: Sensirion SHT11r

Specifications of 28018

• Output Type: Digital - 2-Wire
• Sensor Type: Humidity and Temperature
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

' reset SHT11/15 with soft reset
'
SHT_Soft_Reset:
In high humidity applications, the SHT11 heater can be switched on briefly to prevent condensation.
Another use of the heater is to test the operation of the sensor: by reading before enabling the heater
and immediately after the sensor can be verified by noting a higher temperature and lower humidity.
The following subroutines can be used to switch the SHT11 heater on and off.
Heater_On:
Heater_Off:
Parallax, Inc. • Sensirion SHT11 Sensor Module (#28018) • 07/2003
8
GOSUB SHT_Connection_Reset
ioByte = ShtReset
ackBit = NoAck
GOSUB SHT_Write_Byte
PAUSE 11
RETURN
status = %00000100
GOSUB SHT_Write_Status
RETURN
status = %00000000
GOSUB SHT_Write_Status
RETURN
' reset the connection
' reset command
' only one byte to send
' send it
' wait at least 11 ms
' heater bit = On
' heater bit = Off