Automatic RetroTINK 4K Profiles using a Raspberry Pi

MOTIVATION

The RetroTINK 4K can be controlled via USB serial connection which makes it relatively easy to interface with using an SBC like a Raspberry Pi. This project was created to interface the gscartsw and Monoprice HRM-2218F with the RetroTINK 4K, enabling automatic profile switching when a console is powered on.

CREDIT

• Arthrimus published this video and it inspired me
  • You should probably just buy the SVS once it is released instead of using this software
• Mike Chi made the incredible RetroTINK 4K, and made it very easy to interface with
• superg for the amazing gscartsw

DESCRIPTION

This service detects input changes on the HRM-2218F and gscartsw and automatically loads one of 12 profiles on the RetroTINK 4K (the same 12 profiles which are mapped to the 12 numbered buttons on the remote). The 8 HRM-2218F HDMI inputs are mapped to profiles 1-8 and the lower 4 SCART inputs (the 4 inputs farthest from the 2 outputs) on the gscartsw are mapped to profiles 9-12 while the upper 4 SCART inputs are not used.

REQUIREMENTS

• A [RetroTINK 4K] (either PRO or CE should work)
• A [gscartsw]
• A [Monoprice HRM-2218F] (discontinued, try eBay)
• A [Raspberry Pi]
  • I recommend Raspberry Pi Zero WH or Raspberry Pi Zero 2 WH
  • Non-WiFi versions will also work, but SSH will make things easier
  • The pre-soldered header is nice to have, but not required
  • Any other Raspberry Pi (except for the Pico) should also work
  • Other SBCs should also work, but you may need to modify the provided scripts
• A Micro SD card for the Raspberry Pi's OS
• A computer to program the Micro SD card
• A soldering iron if connecting the Pi to the [gscartsw]
• Solder
• Wire and Wire Cutters or DuPont Connectors and DuPont Wire for the [gscartsw]'s unpopulated EXT header
  (READ this before deciding how to proceed)
• An RS-232 to USB cable to interface with the [HRM-2218F] (an FTDI chipset is recommended)
• A [USB Hub] that can be connected to the Pi
• A USB-C Y Cable to power the [RetroTINK 4K] and communicate with it over USB at the same time
  (make sure to connect the power-only side to the [RetroTINK 4K]'s USB-C power supply)
• A USB-C Cable to connect the [USB Hub] to the data side of the USB-C Y Cable
• A Micro USB or USB-C Cable to power the Pi
• Two [5v 2A USB PSUs]

BUILD INSTRUCTIONS

• Download and install Raspberry Pi Imager (use this link if on Ubuntu).
• Use Raspberry Pi Imager to install Raspberry Pi OS to a Micro SD card (I used Debian Bookworm, the latest release as of 1/1/2025).
• Download ctrl_monoprice_4067.c and Makefile from this repo, and copy the files to /home/pi, then run the following commands on the Pi:
  • cd /home/pi
  • make
• Download read_gscartsw.sh from this repo
  • Follow the instructions in README.md to connect your gscartsw to your device and edit read_gscartsw.sh if required, then copy read_gscartsw.sh to /home/pi and run the following commands on the Pi:
    • cd /home/pi
    • chmod +x read_gscartsw.sh
• Download rt4k_auto.sh and rt4k_auto.service from this repo, and copy the files to /home/pi, then run the following commands on the Pi:
  • cd /home/pi
  • chmod +x rt4k_auto.sh
  • sudo -s
  • cp rt4k_auto.service /etc/systemd/system
  • systemctl enable rt4k_auto.service
  • systemctl start rt4k_auto.service
  • exit
• Connect your [Raspberry Pi], [USB Hub], [RetroTINK 4K], [gscartsw], [HRM-2218F] and both [5v 2A USB PSUs] as shown below in the hookup diagram

HOOKUP DIAGRAM

                PWR | <------- USB Cable -------> [5v 2A USB PSU #1]
[Raspberry Pi] GPIO | <------- 4x Wires --------> [gscartsw]
                USB | <------- USB Cable -------> [USB Hub]

                                 |--- Power ----> [5v 2A USB PSU #2]
          | <----- USB-C Y Cable |--- Data -----> [RetroTINK 4k]
[USB Hub] |
          | <------ USB to RS-232 Adapter ------> [HRM-2218F]

DEBUGGING

Run sudo systemctl status rt4k_auto.service to view the service's logs

EXTENDING THIS PROJECT

rt4k_auto.sh is relatively simple to extend, more devices and more types of devices can be added as needed.

Both ctrl_monoprice_4067 and read_gscartsw.sh are implemented to work the same way when run:

• Write a single number: [0-8] as output to stdout
  (all other output goes to stderr)
• 0 indicates: NO ACTIVE INPUT, [1-8] specifies the active input

By writing additional programs or scripts that follow this protocol, new devices can be polled in the main loop of rt4k_auto.sh. The only current limitation is that no more than 12 profiles can currently be selected .

FUTURE DIRECTIONS

Using the new SVS Commands would provide more than 12 automatic profile options.

NOTES

The HRM-2218F has excellent MiSTer DirectVideo DV1 SPD Infoframe compatibility.

LICENSE

This software is licensed under the MIT License.