Documenting potential hardware modification ideas for the Astro City Mini and other mini variants. Using this thread to get input on design and feasibility.
Project Idea - Use the Astro City Mini to mirror the display from a real arcade cabinet. The real arcade will have a JAMMA inline PCB, with a wireless video transmitter - probably something adapted from FPV gear that is readily available. The Astro City Mini will have its mainboard removed and replaced with PCB containing the wireless video receiver and the LCD driver.
Implementation Details -
Astro City Mini Display - From the only teardown video I can find (
View: https://www.youtube.com/watch?v=GNz5OnHzjb8
) - It appears the LCD inside the mini uses a 24 pin connector, based on the silkscreen on the PCB. The only thing I can find that uses a similar looking connector are a handful of cell phone LCDs. Those LCDs look like they can use a couple of different standards as far as the display protocol goes. In the 24-pin count connector I am only seeing MIPI based displays, so going to assume its an MIPI display. MIPI can be used for cameras MIPI CSI and for displays MIPI DSI, so going to make another assumption that it is MIPI DSI. MIPI, being a high speed serial protocol, has several lanes that it can operate over. I have seen mention of 2 lane and 4 lane screens, with 4-lane typically mentioning 4K. That seems out of the realm of the mini, so assuming 2 lane. The pinout on these displays seems all over the place, so no standard there we can rely on. Based on this site (https://andybrown.me.uk/2012/06/05/nokia-lcd-for-arduino-mega-1/) we might have this connector:
Connector-
24R-JANK-GSAN-TF
https://www.jst-mfg.com/product/detail_e.php?series=120
https://www.jst.com/wp-content/uploads/2021/03/eJAN.pdf
24-pin FPC connector (Flexible Printed Circuit)
MIPI display (MIPI DSI) 2-lane
Displays-
I found a few examples of 3.97", 24-pin MIPI displays, in 480x800, 16.7 Million colors (The Stock Display specs)
https://www.panelook.com/TXW397037S...play-24-pins-MIPI-450-cd-m2-detail_46284.html
Display Driver-
Assuming MIPI, there is an open source Verilog core for driving MIPI displays.(https://github.com/skatanik/dsi_controller)
Looks to be implemented as a Quartus project. This makes you think that a Mister hat for MIPI LCDs wouldn't be out of the question, then its a little bit of IO and audio to have a Mister in the Astro City Mini.
There are a few projects/products out there with HDMI to MIPI displays, but the connector / pin count is nowhere near the 24-pin assumed connector. I have seen examples of high pin count MIPI display drivers, connected to lower pin count displays via adapters - but not much information on specifics. (https://www.amazon.com/Controller-Board-LS055R1SX0-1440x2560-Screen/dp/B07DCHFCJZ)
I don't currently have an Astro City Mini but if I can convince myself that this might actually work, I could pick one up to start reversing. Let me know if there is more teardown and hardware info out there, it has been beyond scarce.
Project Idea - Use the Astro City Mini to mirror the display from a real arcade cabinet. The real arcade will have a JAMMA inline PCB, with a wireless video transmitter - probably something adapted from FPV gear that is readily available. The Astro City Mini will have its mainboard removed and replaced with PCB containing the wireless video receiver and the LCD driver.
Implementation Details -
Astro City Mini Display - From the only teardown video I can find (
) - It appears the LCD inside the mini uses a 24 pin connector, based on the silkscreen on the PCB. The only thing I can find that uses a similar looking connector are a handful of cell phone LCDs. Those LCDs look like they can use a couple of different standards as far as the display protocol goes. In the 24-pin count connector I am only seeing MIPI based displays, so going to assume its an MIPI display. MIPI can be used for cameras MIPI CSI and for displays MIPI DSI, so going to make another assumption that it is MIPI DSI. MIPI, being a high speed serial protocol, has several lanes that it can operate over. I have seen mention of 2 lane and 4 lane screens, with 4-lane typically mentioning 4K. That seems out of the realm of the mini, so assuming 2 lane. The pinout on these displays seems all over the place, so no standard there we can rely on. Based on this site (https://andybrown.me.uk/2012/06/05/nokia-lcd-for-arduino-mega-1/) we might have this connector:
Connector-
24R-JANK-GSAN-TF
https://www.jst-mfg.com/product/detail_e.php?series=120
https://www.jst.com/wp-content/uploads/2021/03/eJAN.pdf
24-pin FPC connector (Flexible Printed Circuit)
MIPI display (MIPI DSI) 2-lane
Displays-
I found a few examples of 3.97", 24-pin MIPI displays, in 480x800, 16.7 Million colors (The Stock Display specs)
https://www.panelook.com/TXW397037S...play-24-pins-MIPI-450-cd-m2-detail_46284.html
Display Driver-
Assuming MIPI, there is an open source Verilog core for driving MIPI displays.(https://github.com/skatanik/dsi_controller)
Looks to be implemented as a Quartus project. This makes you think that a Mister hat for MIPI LCDs wouldn't be out of the question, then its a little bit of IO and audio to have a Mister in the Astro City Mini.
There are a few projects/products out there with HDMI to MIPI displays, but the connector / pin count is nowhere near the 24-pin assumed connector. I have seen examples of high pin count MIPI display drivers, connected to lower pin count displays via adapters - but not much information on specifics. (https://www.amazon.com/Controller-Board-LS055R1SX0-1440x2560-Screen/dp/B07DCHFCJZ)
I don't currently have an Astro City Mini but if I can convince myself that this might actually work, I could pick one up to start reversing. Let me know if there is more teardown and hardware info out there, it has been beyond scarce.