Temp/Humidity/Solar Newbie problems

j4powell

New Member
I recently purchased the basic components to experiment with one-wire. T/H/S sensor, cable and Serial adapter along with Tim's book.

I was happy to get the Temp sensor working with the simple weather code from the book.

I'm not having any luck with the humidity or solar sensor. The Humidity/Solar DS2438 shows up ok with OneWireLister. When I add the Humidity code to simple weather - it runs but gives no results. I've added in the solar code from the bonus downloads and same thing - it runs without error - just no results. I have tried with and without external power, with and without the internal jumper. In every case , Simpleweather with debug on gives me the following:

Found Adapter: DS9097U on Port COM1
Resetting 1-wire bus
Temp Device Supports High Resolution
Time = Sun Oct 21 13:29:42 EDT 2007
Temperature: Device = DS1920 ID = 6D000801550A7110
Temperature = 75.0875 deg F 23.937502 Deg C
Humidity: Device = DS2438 ID = E6000000B6592A26
Supply Voltage = 0.0 Volts
Sensor Output = 0.0 Volts
Temperature = 0.0 C / 32.0 F
Uncomp RH = NaN%
Hum Gain = 1.0
Hum Offset = 0.0
Calibrated RH = NaN%

Humidity = NaN %


Solar: Device = DS2438 ID = E6000000B6592A26
Supply Voltage = 0.0 Volts
Sensor Output = 0.0 Volts
Gain = 1.0
Offset = 0.0
Comp Solar = 0.0%

Solar Level = 0.0%

Any hints on where to look next? It seems like the DS2438 is responding but if the response is correct, it has zero supply voltage.
 
Update and clarification. I spent some more time time going through the forum and discovered OneWireViewer as a diagnostic tool.

With OWV I also see the temp sensor and Humidity/Solar Sensor. Temp sensor reports OK 72degF. Humidity sensor temp output reports 32deg F - (zero C), never changing. Humidity reports zero, ad2 ( The solar sensor I believe) reports zero.

The external power I'm using is just a 12vdc wall wart connected to the screw terminals.

The results don't change regardless of external power or not, with or without jumper.

Thanks in advance for any help or suggestions.

John Powell
 
John,

Is JP1 installed on the board? According to the schematic, which is worded not so clearly,

"remove the jumper for parasitic power operation".
"install the jumper for external power operation".

In this context, "parasitic power" really means getting power off the RJ45 cable.

On this board, the DS18S20 is connected in "parasite mode", with vdd-gnd connected.
It will work without power.

And if you haven't already, get your meter out and make sure the wart is really putting out 12vdc on the screw terminals.
 
Update and clarification. I spent some more time time going through the forum and discovered OneWireViewer as a diagnostic tool.

With OWV I also see the temp sensor and Humidity/Solar Sensor. Temp sensor reports OK 72degF. Humidity sensor temp output reports 32deg F - (zero C), never changing. Humidity reports zero, ad2 ( The solar sensor I believe) reports zero.

The external power I'm using is just a 12vdc wall wart connected to the screw terminals.

The results don't change regardless of external power or not, with or without jumper.

Thanks in advance for any help or suggestions.

John Powell

John,

What happens if you remove the external power and remove the jumper on the board?

Eric
 
Hello Gents - thanks for your replies... I tried the module without external power first, first with the jumper, then without as I read the instructions more closely.

Yes the wall wart is producing 12v (ok 11.3 on the screw terms)

If I remove the jumper and external power then run OneWireViewer I get the same result.

DS1920 works fine - reports 70.7 deg F
DS2438 shows in list, reports temp of 32F (which would convert to 0C), no result in the Humidity Tab and 0 volts out on all three AD readouts on the A to D tab.

See attached file for screen shot.
 

Attachments

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It looks like your DS2438 has gone belly up. Please contact me at support @ hobby-boards.com with your order # and I will get you the details you need to get this resolved.

Eric
 
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