HDMI2SCART

Use with RGBtoHDMI

This device is mainly meant as an accessory for the RGBtoHDMI to drive an analog monitor. It converts the incomming HDMI signal to an analog RGB signal on its SCART output. Note, that it does no scaling or other conversion, so the HDMI source must be capable of providing the necessary 240p/288p signal that is requested by the HDMI2SCART. The RGBtoHDMI already directly supports automatically switching to this output resolution.

General use as an HDMI sink

A second use is to connect it to some regular PC/Mac/Linux machine to use it as display for an emulator. To make this work properly, the emulator must be configured (if this is possible) to generate exactly one display line for each scanline of the emulated machine. The horizontal scaling is not as critical, but integer scaling gives best results. I did manage to set up WinUAE to do this, I can not give advice for other emulators in general.

Power supply

The device uses power that is supplied from the HDMI source. This feature is already pretty well supported, but if you happen to have an older graphics card, you should check this before buying. The Raspberry Pi Zero that is used as base for the RGBtoHDMI works just fine.

Input signal compatiblity

The HDMI2SCART reports a resolution of 1440x288 or 1440x240, depending on the setting of the frequency switch (50/60). This may or may not be translated to 720x288/720x240 by your graphics card. In any case, you need to apply horizontal stretching to get the aspect ratio correct again.

Output signal

The SCART connector provides R,G,B and pure CSYNC, as well as the 2V signaling voltage needed to use the RGB inputs. There is no need for your HDMI source to do anything special with the sync signals, as the HDMI2SCART will generate a standard-conforming CSYNC signal from every combination and polarity of HSYNC and VSYNC.

Audio

When your HDMI source provides an audio signal, this will directly be fed into the SCART output. When you want to provide an analog audio signal instead (as the RGBtoHDMI for example does not support audio), you can plug a 3.5mm stereo cable to the audio input. This will disconnect the HDMI source and use the analog input instead.