HSMM-MESH™ Outdoor enclosure

Here in the Midwest, we are subjected to the entire gamut of weather conditions that mother nature can throw at us.  Extreme cold (-20°F), extreme hot (>100°F), snow, ice, rain, straight-line winds in excess of 100 MPH, etc.  Especially for the nodes that are to be permanently installed outside, I want to house them in an enclosure to ensure that the electronics inside have the best chance of surviving.

In order to find a suitable enclosure to mount a HSMM-MESH™ node outside, I first started by defining some requirements:

• Shall be weatherproof
• Shall be shielded
• Shall be large enough to mount at least one WRT54G series router and any required accessories
• Should be economical
• Should be easy to install/replace entire unit
• Should have bulkhead N-connector mounts
• Should have waterproof Ethernet feed-through

Next was looking at what others have used for outdoor enclosures.

• Sprinkler box - 
• http://hsmm-mesh.org/component/content/article/51-mesh-node-examples.html
• http://www.w5adc.com/HSMM%20Enclosure%20Implementation.htm
• PVC electrical box - 
• http://hsmm-mesh.org/documentation/121-drop-boxes.html
• Surplus NEMA box - 
• http://hsmm-mesh.org/hsmm-mesh-forums/view-postlist/forum-7-austin/topic-237-south-austin-k5amd-oak-hill.html

I like that the sprinkler box is easily found at local hardware stores but it's lack of shielding and appropriate mounting is a problem.  It might still be useful for temporary nodes that you need easy access and semi-weatherproof, however.

The PVC box is another nice temporary node enclosure but I don't know how it will survive long-term in the sun and again, is not shielded.

Surplus NEMA boxes will work, however I don't have a good source for one.  eBay shows enclosures for $100 on up, which wouldn't satisfy the economical constraint.


I'm not sure if I found the die-cast enclosure by searching on my own or found others using them but I found an enclosure that seemed to satisfy all of my constraints and easy on the pocket book too.

What I found was a  Tycon TPENC-DC-10x8x3 Outdoor Die Cast Enclosure

• 10" x 8" x 3"
• IP67 waterproof
• 3 cutouts for N-connectors
• 2 cutouts for Ethernet glands (one gland included)
• Aluminum construction (shielded)
• Painted off-white
• Only $35 (depending on source)*

* As far as I can tell, these are mass-produced overseas and sold under various names and configurations at multiple vendors.

I was impressed enough that I went ahead and bought one to evaluate.

Temperature testing:

After mounting a WRT54GL in the case, I put it in my deep freeze to simulate extreme cold conditions.  I did a 24-hour cold soak with the freezer set to 0°F, the temperature inside the WRT case never got below 21°F, which is still within the specified operating range of the WRT54 routers.  A spray of conformal coating prior to installation should mitigate any issues there.

Sitting in the box downstairs, ambient temperature 68°F, inside the case got to 81°F

I haven't put it in an oven yet with the router running to see how it reacts to heat.

All tests did not have a fan circulating air within the box (I did put a heatsink on the processor) and the router was still mounted inside it's blue/black plastic case.

Sources:

Willigear WOE-001

http://www.wiligear.com/?q=products/accessories/outdoor-enclosure

Titan Wireless:

http://www.titanwirelessonline.com/Die-Cast-Outdoor-Enclosure-2-N-Hole-p/en-tw2n.htm

Amazon (non-Prime):

http://www.amazon.com/Die-Cast-Hinged-Outdoor-Enclosure/dp/B004EI0KKE

Search for "Die Cast Hinged Outdoor Enclosure" and you should see plenty of hits.

Look for a post on how I mounted a router in one of these boxes soon.

Antenna Data!

Over the past few months, I have been collecting data on different kinds and styles of antennas and am finally getting around to publishing the information.  I've created a separate page on this blog to keep the data and will update it when I get more antennas tested.

KC0ALC-1 Digipeater

KC0ALC-103 HSMM-MESH™ router

The current iteration of my digipeater is a WRT54GSv1 router, running APRS4R which is written in Ruby.  The Ruby packages for OpenWRT takes up more than the available memory space on other routers (G and GL versions) so I'm using a GSv1 that has more flash and memory to handle both APRS4R and HSMM-MESH™ firmware.   Previously, I had been using a WRT54Gv2 router with the USB modification and had the OS running on a flash drive, later on an external 2.5" hard drive.  The USB sticks would die after a month or two of usage and the hard drive required a USB hub to provide enough power so I decided to upgrade it to a GSv1.

The TNC is a TNC-X v1, KISS only TNC that I bought at a swapmeet for $5 and the radio is a FM-2030, a 70s vintage mobile radio that I had no other use for.

The TNC is connected to the router via one of the built-in serial ports on the WRT router.  I found a TTL-RS232 converter chip laying around that works on a 3.3V Vcc voltage (ICL3232) so I wouldn't have to add any other voltage regulators. I made up a simple interface-board, dead-bug style, for the converter and used a couple of DB9 cables to provide external

Other additions to the router include a heat sink on the main processor and a fan inside the case to circulate air.  The fan is a 12V fan I found in a junk box with a current limiting resistor to slow it down.  Since this router will be running 24/7 I wanted to minimize the thermal stress on the components.

APRS4R is running as a fill-in digipeater (only responds to WIDE1-1 packets) and also a transmit I-Gate, limited only to the polygon weather alerts coming through the APRS-IS servers.  I further limit the packets to my county and surrounding counties via the APRS-IS filtering I have set up.  I'm using APRS4R right now mostly for the ability to share the APRS data and have other computers connect to the digipeater and use it as a TNC interface.  I have the port forwarded through my home router so I can access my TNC wherever I have an Internet connection and also available to any HSMM-MESH™ routers that are connected to the router.

APRS4R also needs regular restarts to behave correctly (due to a memory leak issue, I believe) so I have a cron job reboot the router at specified intervals.

Here is an overall system diagram:

Some pertinent links:

• http://www.dimebank.com/cak/k6dbg/k6dbg_igate.html
• KC0ALC-1 on aprs.fi