shmups.system11.org

As a followup, I was wrong about the shielding. I was trying to update my DCHDMI from v4.0 to 4.2 without taking everything apart and swapping my GDEMU for the original GD-ROM, but the WiFi connection was just so spotty. I tried routing the antenna out the rear vent (which did require enough disassembly to pull off the upper EM shield), but, even after reassembling everything, and placing the Dreamcast within 6 feet of my access point (line-of-sight, too), I still had connection issues.

I had a laptop next to me, with a terminal constantly pinging the DCHDMI's IP. I tried moving the antenna around, and noticed that, as long as I was touching it with my finger, I could get a consistent ping, and removing my finger returned to the spotty responses. With my finger on the antenna, I was able to check for and download the updates without issue.

After messing around with a couple options, I was able to get a reliable ping with the GDEMU (without the stupid foil shielding I had tried before) and with modem installed, by putting the antenna back in its normal spot, wrapping (point being to touch the solder point) it in enough aluminum foil to cover that shelf of plastic over the modem, from the solder point on the DCHDMI's antenna to the shelf's forward edge, and taping it down.

I didn't test the DCHDMI itself much after this point, but, during the brief period I was testing the network connectivity, I didn't encounter the slow startup problems I had been encountering (DC would get all the way into GDMenu, and then I'd have to wait another 30 to 60 seconds before I got any video out of the DCHDMI).

At this point, I'm convinced that either my antenna is faulty or the DCHDMI just needs a bigger one. I think an external one could be added by drilling a hole into the back of the upper shell, just above the modem.

The first 100 units I shipped of the DCHDMI had the wifi antenna "bridged" which helped solved this issue. However when you bridge the antenna, it severely hurts the reception distance.

Anyways, the problem is not the wifi antenna but the EMI created by the GDEMU. Here is some interesting findings from christof:

https://github.com/chriz2600/DreamcastH ... ctivity.md

Thank you; not sure I would've found that on my own. I'll give the alternate placement a shot when I get home.

The install docs were updated with the antenna placement when this information was found out.

http://dansprojects.com/dchdmi_install.html