Part 1 of 2
I’m traveling this week with a DHAP and the Icom ID-51A dual-band handheld. This combination of hardware permits me to stay connected with my friends on the D-STAR network from wherever I happen to roam – no local digital repeater required. The DHAP is a custom-built enclosure and battery supply for a Raspberry Pi and DV Access Point – a DVAP.
If all this sounds like too much alphabet soup (it is!) let’s first break it down in pieces.
The DVAP is a small USB powered D-STAR transceiver that runs about 10mW of power on UHF. VHF is also available. It’s manufactured by Internet Labs. The concept here is that you plug the DVAP into a USB port on your Windows, Mac or Linux computer, running the proper software and connected to the Internet, and it looks a lot like a D-STAR repeater to your radio — albeit a micro-repeater with only about 100 yards of coverage.
With this arrangement, a user can connect to other repeaters and reflectors on the network. While it’s an effective solution, it’s not elegant or efficient to keep a desktop or laptop computer running all the time just to maintain that connection.
Enter the Raspberry Pi, a single board computer that’s smaller than a pack of cigarettes, costs $35, supports networking, and runs Linux. It didn’t take long for users to see the advantages of this arrangement over the desktop PC and the rapid migration was underway.
You can put all this together for the price of the DVAP and another $50-100 for a Raspberry Pi, memory, associated cables, power brick, and all that jazz. It will work perfectly well setting on your desk or workbench like that, but if you want to take it outside with you, an enclosure to house and organize it all is a really good idea.
Which gets us to the DHAP. Manufactured by Hardened Power Systems, this contraption is a robust enclosure for the DVAP and the Pi that conveniently brings all of the on-board connections out to the front and back panels. NiMH batteries run the show for several hours between charges while a front panel display shows the battery level.
It’s not waterproof, and I suppose you could break it if you tried. But it is a hardened, machined case that’s slightly smaller than a football. Once it’s configured and charged, you just pick it up and carry it with you wherever you go.
Of course, it requires a network connection that can be provided from a hardwired Ethernet cable or via a Wi-Fi network. That Wi-Fi link means it can be easily tethered to your cell phone, which is how I use it on the road, when I bring it home, it automatically connects to my home Wi-Fi.
It’s the ultimate in convenience and portability for the D-STAR enthusiast though it’s not cheap. $300 [US] for the unit with a Raspberry Pi, a little less if you’re bringing your own Pi. And that doesn’t include the DVAP…
More about how I use all this on the road, and a few tips about the DHAP in the next post.