I found the pinout for the 40-pin FPC connector on the schematic from the wiki, but I haven’t found any compatible displays. Is there an existing Seeed or 3rd-party display that “just works” with the framebuffer interface, is the expectation that users create a daughterboard to convert to their chosen LCD/touchscreen IO, or that users create a daughterboard to convert to HDMI/DVI/VGA connectors?
I’d like to use, for example, this Newhaven display:
www.newhavendisplay dot com/specs/NHD-4.3-480272EF-ATXL-T.pdf
Or this Adafruit one:
cdn-shop.adafruit dot com/product-files/1591/SPEC-CH430WQ01-T_Rev.A.pdf
These displays (and plenty of others on the market) have matching pinouts, but they don’t match the NPi i.MX6ULL FPC connector.
| Pin | Display Pinout | Pin | NPi Pinout |
|---|---|---|---|
| 1 | LED- | 1 | 5V |
| 2 | LED+ | 2 | 5V |
| 3 | GND | 3 | 3V3 |
| 4 | 3V3 | 4 | 3V3 |
| 5 to 12 | Red0 To Red7 | 5 | GND |
| 13 to 20 | Green0 to Green7 | 6 to 13 | Red0 To Red7 |
| 21 to 28 | Blue0 to Blue7 | 14 to 21 | Green0 to Green7 |
| 29 | GND | 22 to 29 | Blue0 to Blue7 |
| 30 | CLK | 30 | CLK |
| 31 | DISP | 31 | HSYNC |
| 32 | HSYNC | 32 | VSYNC |
| 33 | VSYNC | 33 | DE |
| 34 | DE | 34 | DISP |
| 35 | NC | 35 | GPIO_8 (“LCD_BL”!) |
| 36 | GND | 36 | GND |
| 37 | XRight | 37 | RESET |
| 38 | YDown | 38 | INT |
| 39 | XLeft | 39 | SDA |
| 40 | Yup | 40 | SCL |
i.imgur dot com/FQtUj2B.png
i.imgur dot com/Z02LsHE.png
Is the expectation that I create a daughterboard which (1) converts the resistive touch to I2C, (2) drives the backlight with a boost regulator from the 5V supply, and (3) modulates the brightness over I2C or by PWM on GPIO_8?
Do any such daughterboards already exist for the NPi board? I found this one for the Beaglebone Black:
4dsystems dot com dot au/mwdownloads/download/link/id/284/
which looks like it could be a good branching-off point to either make a super-simple adapter from the NPi headers to the BeagleBone form factor or to use as a baseline to develop something similar for the NPi.
I’m also open to the possibility of creating a daughterboard with a DVI or HDMI transmitter and connector, like an Analog AD9889 or NXP TDA19988, but that intermediate cabling is not necessary for my product and I’d rather go straight to the display with the FFC.
(Links above obfuscated with “dot” because new users can’t post many links…)
Pinging @Baozhu