|
|
|
|
|
|
|
|
One
of the requirements for running a remote observatory is having the ability to
monitor temperature and weather conditions at the remote site. To accomplish
this, we have begun the installation of a 1-Wire™ ® Weather Station
manufactured by AAG of Mexico.
This weather station is based on the 1-Wire™ ® technology developed by Dallas
Semiconductor. This technology allows tiny sensors to communicate, and drawn
their power from a single wire plus ground. Each sensor has a unique ID encoded
into the chip allowing multiple sensors to communicate along the same bus.
Our initial configuration will consist of a mast mounted weather station providing wind speed, wind direction and outdoor temperature. Additionally mounted to the mast, using the rain gauge modification kit from AAG, we have modified a Davis® rain Gauge to provide rain fall readings. Inside the observatory, two additional temperature sensors will provide temperature readings in the control room and main building. These readings will be periodically uploaded to the website providing real time monitoring of conditions at the observatory. The weather station will controlled by "Wserver" software written by Arne Henriksens
The initial configuration went online April 19 2002. The project has progressed to include a humidity sensor, barometer, lightning sensor, and several additional temperature sensors, as noted in the updates below.
Project Updates |
||
| 4/18/02 |  |
Phase 1 of the weather station went online at 11:45pm EST after we received the backordered DS9097U serial adaptor, and installed the weather station by flashlight. The internal temperature probe did not arrive in time to install with the other instruments. External unshielded temperature, wind speed, wind direction, and rainfall are now functional and online after a cross wired connection in the rain gauge module was corrected. Note: The picture on the left is an updated photo with the lightning sensor mounted. on the mast. |
| 4/19/02 |  |
Web site uploads have been activated, and the html page has been customized to our current web format. We are currently having trouble configuring a current condition overview on the home page. A link directly to the detailed weather page has been established in the interim. |
| 4/26/02 | Temperature sensor was installed in the control room to monitor environmental conditions of the computers and equipment. | |
| 4/28/02 | Temperature sensor was installed in the main hallway to monitor temperature conditions in the main section of the building. | |
| 5/11/02 |  |
Lightning sensor went online today after completing construction of the housing for the circuit and antenna. The circuit board and a DS2423 counter chip was obtained from Jim Jennings at www.jjware.com and the remaining. parts were ordered from www.mouser.com The board was assembled in about 30 minutes. A 12" disposable grill igniter was used to simulate lightning strikes to verify the circuit's operation. The circuit uses two darlington transistors to increase the gain of the lightning pulse, triggering an optocoupler (used for circuit isolation), resulting in an increment of the DS2423 counter. The housing was made from an exterior electric junction box, with an 11" piece of 3/4" pvc conduit to protect the antenna. A 1" pvc pipe plug fit both the flared end of the conduit, and the side opening in the junction box. The unit is attached to the top of a 1 1/4" aluminum mast by a 1 1/4" electric pipe conduit threaded coupler with the threads filed down to create a tight fit on the mast, and fixed with silicone sealant. The circuit board was attached inside the box with double sided tape, and the wires run out the bottom of the assembly. A 9 volt battery sits perfectly upright in the housing and a weather tight cover seals the assembly inside. A drop of silicone sealant was affixed to the top of the antenna to keep it secured inside the the pipe. The photo of the mounted weather station above shows the lightning sensor mounted to the top of the mast. |
| 5/27/02 |  |
Outdoor humidity sensor and barometer have been added to the weather station. Photo shows recently assembled sensor boards being "burned in" for 72 hours before being added to the station. The humidity sensor will be coated in a weather proof coating before it is mounted in a shielded enclosure. The shield will protect the onboard temperature probe from direct exposure to the sun to provide a more accurate outdoor temperature reading. The barometer will be mounted in a small enclosure and located in the control room. |
| 9/3/02 |  |
In order to better manage the 1 wire network, A 1 wire hub was constructed and put online. The hub consists of three DS2409 switching chips which through software can be turned on and off thus separating each cable run to reduce reflections in the network. The three chips have a main and aux port giving 6 available runs. Each segment, has through the socket connection, the ability to supply either 12 volt power or 5 volt power to the devices on the segment. This allows for greater flexibility in the design of the network. The hub was designed by Simon Atkin |
