[DARARepeater] Special Hamvention Display Work Party - Tonight 7PM

[George]

Just making sure the group got this

 

George

 

 

From: Greg AB8RG [mailto:ab8rg at yahoo.com] 
Sent: Monday, April 11, 2016 5:04 PM
To: dararepeater at mailman.qth.net
Cc: George Ewing WD8NHI
Subject: Re-Send: Special Hamvention Display Work Party - Tonight 7PM

 

We are meeting at the DARA B-Road Clubhouse tonight (April 11, 2016) at 7 PM. Please read details below before deciding to show up.

 

Special Hamvention Display Work Party

 

The Hamvention Display is nearing completion and will be available for a demonstration tomorrow night (Tuesday 12 April). Below highlights the current status of the display and the work remaining to be completed tonight.  Please look at the categories and pick the one(s) you would be good at and plan to help us tonight.  This evenings work is dedicated to the display. If you want to socialize, please wait until this Thursday's meeting. Thank you for your consideration.

 

The status of the Hamvention Display System:

 

The pole is fabricated with angle bracket and is drilled with through holes to mount the panels to the pole with bolts.

 

Five panels with five digits each have been constructed. The frames for the panels are equipped with one foot wide angle iron on the top frame rail and the bottom frame rail and is used to mount the frames to the pole. A full rear cover board, made of 1/4" Luan plywood mounts to the frame on the rear with 12 wood screws. The screw hole locations are pre-drilled in the rear cover board.

 

Of the five panels, four are fully operational and each panel has been thoroughly tested with several test barcodes using the barcode scanner and Arduino. As we tested the panels, we noted the failed display digits and moved them to the fifth frame creating a hangar queen. A hangar queen is a grounded aircraft which is kept so that its parts can be used in other aircraft. The fifth display panel is not needed for the demo, however it is the complete spare panel that would be used in event of a failure during Hamvention. We plan to make all repairs to the spare panel within a week, making it available for Hamvention use.

 

As a side note, while testing the panels we also determined the maximum CAT5 cable length that can be used directly couple an Arduino to a display panel. The answer is 15 feet. Any more than 15 feet of CAT5 cable results in digit errors. This is not a limitation for the Hamvention Display System because we are using a line driver / line receiver system to extend the separation of the Arduino and the display panels. The 15 ft result is provided as information to any users of the 74HC595 shift register with an Arduino UNO driving five shift register boards directly with 2 ft jumpers between the boards.

 

Work needed tonight for the Hamvention Display System:

 

Construct a power harness for the pole: 

A 12 volt 20 amp power cable will start at the Astron supply and end at a terminal box at the panels. The terminal box will have a terminal strip, a 4 fuse block, and 4 short PowerPole pigtails to accept the display panel pigtails also with PowerPole pigtails. The cable running along the pole will be enclose in split loom from Tom N8ZM.

 

Finishing  touches on the display panels: 

The panels are complete, except PowerPole connectors need to be crimped on to the 12 volt power pigtails already installed in the display panel. Also, the rear cover board needs to be installed. The rear panel screw locations are pre-drilled in the cover boards. When installing a cover boards, use a pilot drill for the #6x1" screws and serial number the cover to the frame. Do not use a power drill to install the screws, use a hand screwdriver. The frames will split or strip if power tools are used.

 

Arduino to display panel interface: 

A "fan out" board splits the five Arduino to shift register signals to each of the four display panels. The "fan out" board needs to be mounted in a small box on the pole near the display panels. The CAT5 pigtails from the display panels terminate at the fan-out box.

 

Assemble and test the Hamvention Display System:

Several hams are needed to mount 4 panels to the pole (with 4 bolts). The panel CAT5 cables (4) are connected to the fan-out box. The PowerPoles (4) make the connection of the display to the power harness. Several hams raise the Hamvention Display System pole, "Battle of Iwo Jima" style, and hold it vertical while test barcodes are transmitted to the four displays simultaneously and verified for correctness.

 

Disassemble and prepare for transport to HARA Arena:

After a successful test several hams are needed to break down the Hamvention Display System and prepare it for transport to HARA Arena for the demo.

 

Summary:

The Hamvention Display System is nearing an exciting moment. The work by all the volunteers is reaching an important milestone. The Hamvention Display System almost alive.

 

73, Greg AB8RG

 

 

Sent from Yahoo Mail. Get it now <https://yho.com/146xkg> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/dararepeater/attachments/20160411/5a037013/attachment-0001.html>