Newhaven LVDS Capacitive Display Set
This section shows information about the Newhaven LVDS Capacitive Display Set. The iMX8M Industrial Development Kit in this configuration is equipped with Yocto dunfell, kernel 5.4 to support LVDS display with a touchscreen layer. In this case the display is installed on the top of the iMX8M Development Baseboard.
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Mechanical connection
When combined with the complete iMX8M Industrial Kit, the Display Set creates a compact, ready-to-use solution. To assemble them together, the following mechanical and electrical accessories were designed and selected to be part of the Display set:
- TFT LCD 1024x600 Pixels display with LVDS interface and Capacitive Touch with SiS9509 controller
- 4x Hex Standoff Threaded M3 30.00mm long [Manufacturer PN: 971300321]
- 40 Position flat flex cable 50.80mm long [Manufacturer PN: 0150200427]
- 6 pin touchscreen flat flex cable
- necessary spacers
Hardware connection
To enable smooth communication between the board and the display, connect the 40 Position FFC cable for LCD and 6 pin touchscreen FFC cable. To implement the display capabilities, following connections need to be made:
- connection between LVDS Display and iMX8M Development Baseboard connector LVDS0 NHD (J12) using a 40 Position FFC cable
- touchscreen connection between iMX8M Development Baseboard connector NHD Touch (J13) and Touchscreen 6 pin FFC cable
LVDS and Touchscreen cable
Software instructions
iMX8M Industrial kit is preinstalled with Android operation system enabling LVDS and touchscreen capabilities by default. Manual configuration is not necessary, but might be useful in individual cases.
LVDS0 NHD Devicetree in U-Boot
Manually booting with LVDS interface as a primary source for video output:
Rex U-Boot > setenv video 'video=mxcfb0:dev=ldb,edt570,if=RGB666 video=mxcfb1:off' Rex U-Boot > boot
Touchscreen test
Make sure TSC2007 chip is detected and bound as input device:
root@imx6-rexultra:~# dmesg | grep -i tsc2007 input: TSC2007 Touchscreen as /devices/soc0/soc.0/2100000.aips-bus/21a4000.i2c/i2c-1/1-0048/input/input0 evbug: Connected device: input0 (TSC2007 Touchscreen at 1-0048/input0)
Touchscreen events are generated after pressing the resistive layer:
root@imx6-rexultra:~# evtest /dev/input/by-path/platform-21a4000.i2c-event Input driver version is 1.0.1 Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0 Input device name: "TSC2007 Touchscreen" Supported events: Event type 0 (EV_SYN) Event type 1 (EV_KEY) Event code 330 (BTN_TOUCH) Event type 3 (EV_ABS) Event code 0 (ABS_X) Value 3529 Min 0 Max 4095 Event code 1 (ABS_Y) Value 375 Min 0 Max 4095 Event code 24 (ABS_PRESSURE) Value 0 Min 0 Max 4095 Properties: Testing ... (interrupt to exit) Event: time 1457899907.959665, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1 Event: time 1457899907.959665, type 3 (EV_ABS), code 0 (ABS_X), value 1657 Event: time 1457899907.959665, type 3 (EV_ABS), code 1 (ABS_Y), value 2486 Event: time 1457899907.959665, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 3268 Event: time 1457899907.959665, -------------- EV_SYN ------------ Event: time 1457899907.969094, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 0 Event: time 1457899907.969094, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 0 Event: time 1457899907.969094, -------------- EV_SYN ------------