Not long ago I did some pointless mods to my Dingoo game device. I added a power LED and a good old fashioned serial port. I called them pointless because the LED just tells you it’s on, and usually you can tell that from other hints. As for the serial port, at the time I put it in, I didn’t even have a way to connect to it, so that was even more pointless. At the time.
Since then, I’ve ended up using the serial port quite a bit – I had an FTDI prototype chip in my parts bin, and made a USB to Serial converter to connect the port on my Dingoo, then installed Minicom on my linux laptop. This has come in handy a few times as I’ve been hacking around with the linux kernel and trying to learn more about the boot sequence. I’ve baffed up the Dingoo a few times such that the serial port was the only way to access it.
As for the LED, when I wired it in originally I just connected it directly between Vcc and Ground. The LED is rated for 3.2 to 3.5 vdc; the battery in the Dingoo is rated at 3.7v nominally. I’ve seen its output as high as 4v though. Needless to say, the blue LED was fried in only a matter of days. Ooops.
So I had to go back in again tonight, and while I was replacing the blue LED (and adding a resistor to limit the current) I took a couple pics.