My APRS HamHUD-II

My HamHUD-II "Brain Child" of Steve KA9MVA What's a HamHUD? Visit Steve's site for info from the source From there you can download the firmware, schematic, manuals and lots more

Firmware and Windows Loader Please Visit Steve's site Dale's ReadMe.txt file for the Windows Loader

Assembly Here's my HUD PCB after everything but the socket for the MAX232ACPE (need to get the low profile socket still) and extension wires to the LEDs, 'whiz wheel' encoder, and switches Notice the two 10 Ohm resistors at R14? The schematic calls for 1 to 5 Ohms there - two 10 Ohms in parallel give a measured 5.2 Ohms

A view from one side

And the other

Here you can see how I 'tweeked' the header strips

Glue? Yea, glue - hot glue to be exact. If you've noticed, several components on the PCB are left 'hanging' in the air. The regulator, the piezo buzzer and the caps in the lower right corner. Since this device is meant to be used in a mobile environment (read 'lotsa vibration') I figured it would be worth it to 'tack' things down a bit You'll also notice that C7 is tilted - that's to avoid making the assembly too tall You'll also notice that the regulator leads were bent VERY close to it's case. That prevents any potential of the metal tab shorting against R14

Also visible in this image are the red paper washers I use to insulate the stand offs from the infamous "+5V hole" on the LCD display board You see the problem here? Hindsight is wonderful - see below for what I missed here as well!

Below you can see the hole clearly (viewd from the LCD side, oposite from the image above)

And here's another view of what I did about it

Finishing up
Box turned into a case and the 'innards' applied A drop and two of super glue hold the LEDs into their holes

Added wires to the encoder, LEDs, and switches Yup, lotsa loops - idea is to allow at least partial disassembly without unsoldering things These loops may well act as 'antennas' for RFI - we'll see, they may have to be shortened or ferrites added

A knob and a couple screws added OK, call me rebelious - I used a black push button, not the red one - hey, the colors match

Save that LCD On a whim, thought I'd try a plexiglass cover - protect the LCD

Smoke Test! NO SMOKE! The top two lines are blank due to no TNC or GPS being connected IF there has ever been a TNC connected, you can call up the stored callsign and skip the 'callsign callup' by holding in the 'beacon now' button while powering up

And then, about 30 to 45 seconds later SMOKE!

Compare the appearance of this cap with the images above. Pretty dramatic. Made me jump That's what I get for not paying attention to the polarity of an electrolitic. Give Steve's design credit, the HUD kept running inspite of the exploded cap! Also note that I've changed the DB-25 leads. Old I/O cards are way handy!

FINISHED!

Finaly done. Even used the firmware loader to update the firmware to 2.4.010a

This view shows the top side sunshade - helps to prevent glare and helps keep the box cool

This view shows the added rear side sunshade - just a piece of notepaper with several coats of flat black spray enamel

You can see here the 486 CPU fan used to pull cooler air in accross the LCD and out the back of the HUD. With the sun shades, this has so far prevented the LCD from doing the 'fade to black' over heat problem

Finished HamHUD-II being given a check over by a true high temp environment expert

Steve has setup an email reflector for HUD builders/users

Click HERE for the complete KC7ZRU site