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[aprssig] Latest HamHUD II+ Pictures and Details

Jason Rausch jason at ke4nyv.com
Mon Jun 29 03:26:47 UTC 2009

PREFACE:  I posted this message on the HamHUD SIG several night ago and so far it has a luke-warm response.  Steve KA9MVA is working on a whiz-bang HamHUD 4, but at the same time I am working on this version for those who simply want a "head-end" that can be tied to any 2M radio and have HamHUD functionality.  I figured it was worth posting here to keep the APRS community in the loop...

Now that I am pretty much settled into my new job and house, I have picked back up on this project. I received the latest boards the other night and built up a prototype to test and photograph. So far, I am pleased with the results and the test unit is working well.

This version has a built-in modem. Its a modified OpenTracker
1+ design flashed with the 4800 baud KISS firmware. This made for a perfect
match with the HamHUD II platform.  I have taken great care NOT to refer to the internal modem as a TNC because then it gives the false sense that its a full-blown internal TNC with connected mode, ect.  True, the hardware is a full OpenTracker 1+ (minus temp sensor), but when flashed with the KISS firmware makes for a great basic KISS modem.

I did some major design changes between the last version and this one. The
biggest change was swapping everything but the LCD and user interface to the back side of the main PCB. This was done to allow the LCD to lay closer to the main PCB. With the parts on the same side as the LCD, the spacing had to be greater to accomodate the height of the PIC, voltage reg. and a fee other taller components. Even though it's 90% surface mount, I just could'nt make it work.

This time, the gap between the LCD and main board is exactly the thickness of an FR4 PCB. In fact, I used an old RTrak prototype board to do the spacing for me.

The power/communications interface is a common DB9 Male and is located on the right side edge of the board. The pinout stayed the same, the only difference is, the bottom row (four pins) is on the LCD/UI side of the PCB.  I decided to abandon the less common DB15 used on the RevE HamHUD.

The case being used is the same height and width of the RevE case, only half as thick. It makes for a smaller unit that can be easily flush mounted to any surface or tucked into other places that the old RevE was just too deep for, like over head, above the rear view mirror. I don't have a milled front panel yet to show off, but I have one marked off and ready for hand milling. I will also be sending several cases off to Jim at APRSWorld, LLC for some milled prototype cases. Jim always does an awesome job, so I expect him to be the milling shop for this project.

Enough yapping, here are some pictures:


Another component I am working on is the matching breakout board for the HH2+. This board is much like the original, but instead of a two serial connectors for TNC and GPS, there is only one for the GPS and a DB9 Female for the radio interface (TX audio, RX audio and PTT).

On the old RevE, we had a single switched +5VDC output. On the new HH2+, there is a switched +5VDC and a switched source voltage output. That means, whatever you put in to power the HamHUD, the same voltage level comes back out on this switched source pin. This was done with the new breakout board in mind. The breakout board has a built-in 10A relay that is controlled by the HH2+'s switched voltage. We also added two PowerPoles to the board. One is source voltage (red and black) for both the HH2+ and the radio. The other (blue and black) is the switched output used to remotely power up/down the data radio.

As with the original version, the switched +5VDC is also ran to the GPS port to remotely power the GPS on and off. With a flick of the HH2+'s front switch, you can power on the HH, radio and GPS all at once.

Here are some pictures of the breakout board:


Ever since the RevE kits ran out, there has been an underground demand for either a HamHUD in the current state or somthing new, such as this II+ version, so I hope the demand has sustained.

The point I want to press here is, this new version will essentially be a lower cost version of the RC-710 head unit.  The RC-710 is meant for the end user to tie to any 2M radio for APRS function.  The HamHUD has always been in this catergory, the road block was the need for an additonal piece of hardware, the TNC or modem.  With it built in now, there is nothing more needed than the radio and a GPS.

Bob is always pushing the two-way functions of APRS and in the HamHUD community, we echo this.  The challenge has always been displaying this two-way data.  We can't take away the fact that the D700/710 does this well, but this option requires you to buy a whole new radio as well.  The HamHUD is a great alternative.  Having all of the important information up front is there, current network traffic, messaging, weather data, objects, hooking objects, ect.

The HamHUD even supports waypoint output, so you can keep your GPS mapping of other stations.  There might even be an upgrade down the road to support the Kenwood output format for the AvMap users.  At this point, the $GPWPL string is supported and that covers just about every GPS out there with a NMEA serial interface.

I do not have a set date on having these ready, but I am getting much closer to that point. Since the board is 90% SMT, this will all be done at a pick and place SMT shop. The remainder will be done in-house, including the initial flashing of the HH PIC and OT1+ processor to the KISS firmware. We are entertaining the idea of a partial kit where the end user installs all of the through-hole parts, about eight and then installs the whole unit into the pre-milled case.


Jason KE4NYV
RPC Electronics

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