I have a 39 pin 4 lane MIPI display with a FH26-39S-0.3SHW 0.3mm 39 pin FPC connector that I want to connect to RPi5.
The Plan
Never done this before and I believe I have to:
- connect the display with RPi's CAM/DISP 0 or CAM/ DISP 1 with a tailor-made FPC cable
- figure out what GPIO and how to define them in the driver for the pins that the display requires, but not within the DSI CAM/ DISP 0 or 1's 22-pn port
- sort out signal conversions according to the display's specs (there's a few signal input and IO power supply with 1.8v which I think the RPi can't do out-of-the-box)
- write and build my own driver based on some existing driver with the init code of the driver IC, define and implement the memory addresses of the driver's functions according to the driver IC's data sheet, and compile the driver with Raspberry Pi's kernel source tree, and subsequently make a kernel module
I do have a detailed specs of the panel and data sheet of both the driver IC and the touch panel IC.
Questions
- When designing the FPC cable, is there any specs I have to follow like impedance etc? (I cannot find any 0.3mm 22-pin to 22-pin FPC cable anywhere. It seems most MIPI related FPC connectors are in odd number like 51-pin, 61-pin or 40-pin)
- In fact why does RPi design decided to use a 22-pin MIPI connector on RPi5? I see most other SBC uses 39/40-pin MIPI connector and so are most 4-lane MIPI panels and accessories from FPC cables to breakout board when it comes to display related hardware design
- because the display uses 1.8v in some interfaces (pin 28 RESX, pin 29 VDDIO, pin 34 TP-1V8, pin 37 TP_RESET), should I use a level shifting voltage translator like a TXS0108E https://www.ti.com/lit/ds/symlink/txs01 ... e.com%252F?
- any reference or data sheet from RPi of which specific pins I can use for the pins from the display to the host that is not in the DSI CAM / DISP port? I assume one cannot just use any exposed GPIO pins as peripherals are now controlled by RP1?
- Are the I2C pins in RPi 5 all operating on 3.3v? (Is there an implication that if the touch panel IO power supply is 1.8v, meaning the SDA and SCL pins will also have to operate on 1.8v?)
Suggestion of any articles / video / forum discussion / GitHub issues related to the objective is welcome as I really want to dig deep in this and learn throughout the process.
The Plan
Never done this before and I believe I have to:
- connect the display with RPi's CAM/DISP 0 or CAM/ DISP 1 with a tailor-made FPC cable
- figure out what GPIO and how to define them in the driver for the pins that the display requires, but not within the DSI CAM/ DISP 0 or 1's 22-pn port
- sort out signal conversions according to the display's specs (there's a few signal input and IO power supply with 1.8v which I think the RPi can't do out-of-the-box)
- write and build my own driver based on some existing driver with the init code of the driver IC, define and implement the memory addresses of the driver's functions according to the driver IC's data sheet, and compile the driver with Raspberry Pi's kernel source tree, and subsequently make a kernel module
I do have a detailed specs of the panel and data sheet of both the driver IC and the touch panel IC.
Questions
- When designing the FPC cable, is there any specs I have to follow like impedance etc? (I cannot find any 0.3mm 22-pin to 22-pin FPC cable anywhere. It seems most MIPI related FPC connectors are in odd number like 51-pin, 61-pin or 40-pin)
- In fact why does RPi design decided to use a 22-pin MIPI connector on RPi5? I see most other SBC uses 39/40-pin MIPI connector and so are most 4-lane MIPI panels and accessories from FPC cables to breakout board when it comes to display related hardware design
- because the display uses 1.8v in some interfaces (pin 28 RESX, pin 29 VDDIO, pin 34 TP-1V8, pin 37 TP_RESET), should I use a level shifting voltage translator like a TXS0108E https://www.ti.com/lit/ds/symlink/txs01 ... e.com%252F?
- any reference or data sheet from RPi of which specific pins I can use for the pins from the display to the host that is not in the DSI CAM / DISP port? I assume one cannot just use any exposed GPIO pins as peripherals are now controlled by RP1?
- Are the I2C pins in RPi 5 all operating on 3.3v? (Is there an implication that if the touch panel IO power supply is 1.8v, meaning the SDA and SCL pins will also have to operate on 1.8v?)
Suggestion of any articles / video / forum discussion / GitHub issues related to the objective is welcome as I really want to dig deep in this and learn throughout the process.
Statistics: Posted by csvke — Tue Nov 05, 2024 9:01 am — Replies 1 — Views 17