GCN Wavebird Receiver Power Draw

[PityOnU]

I recently purchased a Gamecube controller to PC USB adapter and am enjoying it immensely when used in conjunction with Dolphin.

However, I am encountering an issue and I figured this would be the place to post about it.

When I use 2 wired controllers, 1 wired controller, or 1 Wavebird controller, the adapter works great. However, when I plug in the receivers for 2 Wavebird controllers, my computer stops registering input from either. The lights on the receivers still light up, just no registered input.

As far as I can tell, this has something to do with the power consumption of the wireless receivers when compared to a wired controller.

I am curious if anyone knows the power draw of the wireless receivers, or the wired controllers themselves for that matter. I'm trying to determine whether the limitation is coming from the power supplied via my USB port (although it is a USB 3.0 port and should be able to deliver more than the required amount), or whatever is the equivalent of a voltage regulator in the adapter itself (to change 5V from USB to 3.3V for the controllers).

If it is the former, I will look into getting a Y-adapter and testing that. If it's the latter, I will need to find a beefier regulator somewhere and do some high-stakes soldering.

 

[Madridi]

Most likely irrelevant, but just to make sure your bases are covered: both receivers are set to different frequencies right?

 

[PityOnU]

Most likely irrelevant, but just to make sure your bases are covered: both receivers are set to different frequencies right?

Of course! The two controllers I was testing are actually from different hardware revisions (at least it seems that way) and used different wireless bands - i.e. the receiver from one set at channel 16 will not pick up data from the other if it is set on channel 16. The controllers only register on their respective receiver.

Unrelated - GBATemp is horribly, horribly broken in IE11 on Windows 8.1. It may be a misconfiguration on my end, but it only started happening recently and I've always used the IE+Windows super-combo move.

 

[PityOnU]

If anyone is interested, I had the adapter apart today and prodded around with an oscilloscope.

The entire board (the USB HID IC and the controllers/receivers) runs on 3.3V coming from a Holtek 7533-1 voltage regulator in a SOT89 package. The part is only rated to supply 100mA at 3.3V, and with one Wavebird receiver that's no problem. Plug in the second receiver, however, and the power draw is too much and the main power rail of the board gets pulled down to 2.8V. (Fun fact: the Wavebird receivers still function at this point, it's just the main IC in the adapter that doesn't.)

After some quick research I've found Holtek makes the 7333 in a SOT89 package that has the exact same dimensions but can output up to 250mA at 3.3V. I'm going to get a sample of the part from somewhere and swap it out, hopefully that should do the trick.

Mayflash should have done it from the start, though. The entire board (with Wavebirds included) only registers as pulling 300mA over USB which gives plenty of headroom.

EDIT: Also, I mistyped the title of this thread. It should be "Wavebird Receiver Power Draw"