__NOTOC__
[[Image:Hih4030.jpg|thumb|right|Honeywell HIH-4030]]
===Overview===

The Honeywell HIH-4030 is a simple relative humidity sensor. It outputs an analog voltage and needs an additional temperature sensor for compensation. The sensor was flown only once for testing...

{|border="1"
|-valign="top"
||Module name||meteo/humid_hih
|-
|Sensor type
|humidity
|-
|Range
| 0 .. 100 %RH
|-

|Resolution
|? %RH
|-
|Refresh rate
|4Hz
|}

[http://www.sparkfun.com/datasheets/Sensors/Weather/SEN-09569-HIH-4030-datasheet.pdf Product data sheet]


===Hardware===
Supply the sensor with 5V and connect the output with an ADC input through a 68kOhm/36kOhm resistor bridge. Standard pin is ADC_3 (AD0.6) on ADC1/J10 for the Tiny/TWOG. We used the temperature sensor part of the SHT75 for compensation.

Supplier:

[http://www.sparkfun.com/products/9569 Sparkfun]

==== Wiring ====
{|border="1"
|-valign="top"
||'''Tiny/TWOG ADC1 pin'''||'''Tiny/TWOG ADC1'''||'''HIH-4030'''
|-
|1
|GND
|GND
|-
|2
| +5V
|5V
|-
|3
|
|
|-
|4
|
|
|-
|5
|ADC3 (P0.30)
|OUT (through resistor bridge)
|}


===Usage===

To use the humidity sensor add:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
  <modules>
    <load name="humid_hih.xml"/>
  </modules>
</source>
}}

The ADC pins can be configured through defines, e.g.:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
  <modules>
    <load name="humid_hih.xml">
      <define name="ADC_CHANNEL_HUMID_HIH" value="ADC_4"/>
    </load>
  </modules>
</source>
}}


===Result message===

The raw data (humid) and the converted result (fhumid/ftemp) is written to the log file. The message is automatically sent when new data is received, it does not have to be added to the telemetry file.
{{Box Code|conf/messages.xml|
<source lang="xml">
  <message name="HIH_STATUS" id="96">
    <field name="humid" type="uint16"/>
    <field name="fhumid" type="float" unit="rel_hum" format="%.2f"/>
    <field name="ftemp" type="float" unit="deg_celsius" format="%.2f"/>
  </message>
</source>
}}


Sample log file lines
 (none)

[[Category:User_Documentation]] [[Category:Modules]]