Very large LED Display

With the small LED 20x15 matrix I noticed significant power loss when using the easy connectors for the LED strips.  I didn't see this problem when I soldered the LED strips, it's a pain but seems like worth the effort.  I used a 5v 20amp power supply with the 20x15 matrix.  With the large LED matrix each LED strip will have a 180 LEDs (8.2 ft).  I am not planning on running all the LEDs while at full power.  White at full power each LED draws up to 60mA.  I did some testing and this seemed very accurate.  I also needed to know how my power supply would handle over current conditions.  I shorted out the 5v side and was happy to see that the cheap chinesse power supply had over current protection (not that I want to exercise this).  

I will have a total of 150x14=2100 LEDs  ( I'm using 300 LED strips).  

   150LEDs x .06mA = 9A  again this is not a condition I will be running.  But I need to know the worst case.  This is also at the brightest level.  I am planning on running it at 150 (highest 255) and avoiding lighting all LEDs at White.

I have decided on using two 5v 60AMP power supplies.  

https://www.ebay.com/itm/5V-12V-24V-48V-Power-Supply-Driver-AC110-220V-TO-DC-Switch-adapter-For-LED-Strip/372130850519?var=&hash=item56a4ba26d7&enc=AQADAAADAFjVrDbVsZ8oH%2F8PNHtt9VX4%2Fw7FZcmMuqsX8uaFEduVSz4vIe%2FNsHnySsSb2Y%2Fh06UBzvwT7x0q8j8223IVcmn9k6O6ojzxe4je7mWSKfxBPHayb5V0vxzw1ZO3tH7ySO%2BRlquKKulIr9PsFBmykHmBEdEZvP%2BQjsS96kGRmf0jLqqiwJ7EQPSsy58HaK5nV4F5CTb7iINV9DRtdS23GjdcJCc8z7yO9ygOQ31FAvfzth26%2FZpaWxFoqR6flCSW1bBh9%2F8YngTTqft%2Bun44qhaONK6NB3UavjefCPRjBkB4Rj5DXMVBLfVSwebtreJTB7EjYtcKdy52GvWhsieW0KDRnz0UZ1TSSHSm3nspmnZDt%2B2hwBN%2BEfX7npL9tIUkuusplMqdc1klLacNDTERFzevFGiW5gmdp60h4baS%2BaBjAtJMcu2ZkP%2F2cTgyz6ZTFbu5%2B0MuKXVtBWJ%2Bic3CigPxMnkvTX%2FgoC%2F9a4PnCGwEiyOEHxLggZSKWUaNilPhFz4BfoXwHWs1EoJxkwc5o9AlWY9%2BKlooLfX7PRvx0C2poDUTTgLkoQBWgEQXrcchgx%2BktT7Q%2BScQUuYboBe1tEi%2F%2BPqi9b3z21gPcWQxplLkZHEU7m70Tho%2B3dZW%2B5y8d51HpYp7tFD%2Fxdu05h8jUfLwYas9pK%2BHIdBY6MFEHcadrV%2FxF7coVLMHuIxizw56RG40RQXX3Jvtc3L8RXCkopWYHqZtQGufDKBs1v2A5o8vPZIYfk7ePhaLQ3EeKpDxcOrx0v92rQ4MZpVXV550S2...

One area I am concerned about is the the environment that the power supplies will be running in.  The barn does not have AC and gets hot and very humid in Maryland.  I am planning on mounting mounting a fan to help cool the power supplies.  At this point I'm leaning towards a 120v fan instead of a 5v fan, mainly because I need this system to work for year after year, and I think the 120v will be more reliable in the long term.

I was looking for a method to enter new phrases that would be displayed.  With the 20x15 display everything was hard coded, this would not work with this display.  I wanted to find a way to enter new phrases with a USB keyboard.  The Arduino could not work directly with the USB keyboard.  I found this device and ordered one.

http://www.hobbytronics.co.uk/usb-host-board-v2?keyword=usb%20host

This would communicate I2C with the arduino and I could order it with the USB keyboard profile already loaded, less work for me to do :D    This worked great, at first I was using a USB keyboard that had a USB port on it, and the device would no recognize it.  I then found a simple USB keyboard (no USB host ports on it) and it worked perfectly, this was also nice an inexpensive.  

hello

One important item I noted.  I need to make sure I have a very strong mounting case to allow "Anyone" to connect the USB keyboard.  I don't want people not familiar with the hardware to have to hold the devices to connect the USB keyboard.  I need to mount this securely in a box.  Now I can get input form a USB keyboard.

Features I need to add to support this.

1.  I will have four "Phrases" being displayed in a rotating pattern.  When I see "xxxx" I will know that new data is coming in.  I will flash  some LEDs, green, as a visual feed back to the operator.  

2.  Need to work out the buffer timing.  The default "USB Host program" checks every 5 min.  I need to create a buffer on the Arduino side, so I can handle not being spread across USB Host buffer.

3.  Need visual feed back that each "phrase has been accepted".

4.  Go back into display mode