Troubleshooting

The Interceptor is not recognized by the computer or software hangs when trying to access it.

Please check that the red LED on the Interceptor is on and the blue one is off (while the Game Boy is turned off). If this is not the case, you should check if the firmware was flashed properly. If indeed only the red light is on and it is still not recognized or software hangs while accessing it, you should try a different USB cable. At this point it is not clear why this matters and maybe this hints at a flaw of the USB design on the current Interceptor PCB, but there have been reports of this being caused by a USB-C-to-USB-A-to-USB-C adapter chain (see #8).

Also make sure that your Interceptor has the most recent firmware version. Especially version 1.2.0 massively improved compatibility as it introduced MJPEG encoding.

I see the standby screen (in color), but when I start the game it turns gray and the game does not show up.

This is very likely a USB problem and an outdated GB Interceptor firmware. The Interceptor only uses the rp2040's USB1.1 port, which is at its limit when streaming video. It is allowed to send a packet of data every millisecond and it may not miss any of these opportunities or the video stream will break and during the game it is slightly more prone to miss its time slot.

Note that the colored standby screen was used on earlier versions of the Interceptor. Please try the most recent firmware version. Especially version 1.2.0 massively improved compatibility and USB bandwidth as it introduced MJPEG encoding.

If that does not help. try to plug it into a USB slot that is not shared with other devices, ideally start with one on the back of your PC before trying any at the front or on USB hubs.

I can pick the Interceptor in some software, but do not get an image.

If you do not even get the "Waiting for game..." screen, this can have several reasons. Here are some items to check:

*Make sure that your Interceptor has the most recent firmware version. Especially version 1.2.0 massively improved compatibility as it introduced MJPEG encoding.

• Try a different USB port, preferably one directly on your PC. The Interceptor is only a USB 1.1 device, but it runs in so-called isochronous mode. This means that the USB bus has to periodically receive new data, which can conflict with other isochronous devices and which can be a problem behind USB hubs. Unfortunately, even ports on your PC can be internally connected to a problematic hub (especially if they are somewhere at the front and not on the back directly connected to your motherboard). Also, keep in mind that a USB1.1 takes up a specific time on the USB bus and not a specific bandwidth. So, even if you plug the Interceptor into a USB3 port, this slow USB1.1 device achieves only little bandwith, but still takes a long time to transfer the data and blocking the USB bus while doing so (actually, it blocks other USB2 devices because USB3 is somewhat seperate). The point is that the Interceptor does not get along well with other devices on the same bus.
• If the software offers options for the video format, please select the following if available:
  • Image format: MJPEG
  • Framerate: 30 fps
  • Resolution: 1280x1152
• Check the Host software compatibility list to see if it is a known problem. If it is not on the list, you might want to try a software from that list first to rule out compatibility problems here. (Please report if that other software worked, so it can be added to the list.)

The Interceptor shows "Sorry, I made a mistake."

This indicates that the Interceptor received an event on the bus that made no sense. Usually this means that the game did something unusual which the Interceptor could not follow. Please report this as an issue here and report exactly what game you played, which Game Boy model you used and at which point in the game this happens.

The Interceptor shows "Sorry, I could not keep up."

This indicates that the Interceptor was not able to follow the game's instructions fast enough. If you were running a Game Boy Color game, this is to be expected and they are not supported by the Interceptor. If it happens during a classical game, please report this as an issue here and report exactly what game you played, which Game Boy model you used and at which point in the game this happens.

The image is mirrored

You are probably viewing the image in the selfie-preview of a video call software (Discord, Zoom, FaceTime etc.). These mirror the image because it feels more comfortable for most users if their preview behaves like viewing themselves in a mirror. Some software allows you to disable this feature, but in all cases other users in the video conference should see your image correctly.

My Game Boy does not start and there is a buzzing sound from the speaker

This has been observed for low batteries in combination with games that use a BA6129 supervisor chip. These are "Ultima Runes of Virtue II", "Top ranking tennis" and some copies of Zelda and Mario 2. The supervisor chip seems to oscillate between its "Game Boy running" and "Voltage too low to run" state. It is not entirely clear how the Interceptor influences this, but the issue is resolved by replacing the batteries with fresh ones. (See this comment and the following tests and discussion for details.)

Semi-transparent objects in the game randomly disappear and reappear

If they appear semi-transparent on the original Game Boy, then they are actually flickering very fast. Because of the lower framerate the Interceptor will randomly pick up frames in which the flickering object is visible or not visible, making them disappear for a few frames and reappearing again. In this case, you should make sure that frame blending is enabled by pressing the mode button. This will mix the internally rendered frames which should result in a similar semitransparent effect as on the original screen.

Also make sure that your Interceptor has the most recent firmware version. Especially version 1.2.0 massively improved the presentation of flickering effects as it allows to show exactly every seconds frame (30fps mode) or even every frame (60fps) if supported by the host software.

How can I receive every single frame at 60fps

The GB Interceptor allows the host software to pick either 30fps or 60fps. The 60fps mode is not 100% compliant with the USB Video Class specifications (i.e. it drops color information), but there are several examples of host software accepting this format (for example OBS). Check the settings for the video source to see if you have an option to request 60fps.

If set to 60fps the standby screen of the Interceptor should show a warning that this might not be compatible. The standby screen is should be visible on every host software and does not run at true 60fps, but as soon as the game starts, the framerate should reach 60fps and if there are incompatibilities with the host software they should show at that point.