KTM-MS68
Compact RK3568 development board for embedded signage. EDP and MIPI display, PoE, a wide 5–12 V DC input and Wi-Fi 6 + BT 5.0 on a 90 × 80 mm board.
Flashing, the firmware API and the guides apply to every board. This page covers what is specific to the KTM-MS68: its connectors, pin assignments and electrical limits.
Connector map
Swipe sideways to see the whole board. Tap a connector to jump to its pin definition. Positions are schematic, not to scale.
Specification
| OS | Android 11.0 |
| CPU | Rockchip RK3568, quad-core Cortex-A55 up to 2.0 GHz |
| GPU | Mali-G52 2EE — OpenGL ES 1.1/2.0/3.2, OpenCL 2.0, Vulkan 1.1 |
| DDR | LPDDR4 / LPDDR3, 2 GB / 4 GB |
| Flash | eMMC 5.0, 8 GB / 16 GB / 32 GB |
| Wi-Fi / BT | 802.11 a/b/g/n/ac/ax + BT 5.0, 2×2 MIMO, dual 2.4 / 5 GHz |
| Ethernet | RJ45 gigabit (1000 M) |
| Screen interface | EDP, MIPI |
| RTC | Yes — with scheduled power on/off |
| Camera | Via USB |
| USB | 1 × USB 2.0, 1 × USB 3.0 |
| RS232 | 1 (external output port) |
Power: DC 12 V / 3 A via 5.5 mm barrel; the DC-in header accepts 5–12 V (current depends on screen size).
Internal expansion: 1 × RS232, 3 × USB 2.0, 5 × GPIO, speaker, microphone, I2C, EDP, MIPI and PoE.
Board dimensions
| Size | 90 mm × 80 mm |
| Thickness | 1.6 mm |
| Top clearance | 15 mm |
| Bottom clearance | 2 mm |
Serial ports at a glance
The RS232 header is driven through the standard serial interface — open the device node below.
| Port | Device node | Type |
|---|---|---|
| RS232 | /dev/ttyS9 | RS232, full duplex |
See the firmware API overview for how the device API drives the board (power scheduling, GPIO, display, network, kiosk lockdown).
Display ports
3.4 EDP port — dual-contact, 2.0 mm
Backlight enable, PWM and 12 V supply are integrated into this connector (pins 22, 23 and 26–29).
The datasheet titles this a 20-pin connector but defines 30 pins. Verify the connector against your panel.
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | NC | NC | NC |
| 2 | GND | GND | Ground |
| 3 | EDP_TX1N | Difference data | Channel 1 |
| 4 | EDP_TX1P | Difference data | Channel 1 |
| 5 | GND | GND | Ground |
| 6 | EDP_TX0N | Difference data | Channel 0 |
| 7 | EDP_TX0P | Difference data | Channel 0 |
| 8 | GND | GND | Ground |
| 9 | EDP_AUXP | Data clock | Difference signal |
| 10 | EDP_AUXN | Data clock | Difference signal |
| 11 | GND | GND | Ground |
| 12/13 | EDPVCC | VCC | VCC 3V3 |
| 14 | NC | NC | NC |
| 15/16 | GND | GND | Ground |
| 17 | EDP-HPD | HPD | HPD |
| 18/19/20/21 | GND | GND | Ground |
| 22 | LCD_BL_EN | Backlight EN | Backlight enable |
| 23 | LCD_BL_PWM | Backlight PWM | Backlight PWM |
| 24/25 | NC | NC | NC |
| 26/27/28/29 | LCD_BL_VCC | BL_VCC | VCC 12V |
| 30 | NC | NC | NC |
3.10 MIPI port — 40-pin, 0.5 mm
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCOM | NC | NC |
| 2 | VDD1 | VCC | 3.3V |
| 3 | VDD2 | VCC | 3.3V |
| 4 | GND1 | GND | Ground |
| 5 | RESET | Reset | LCD_RESET |
| 6 | NCP | NC | NC |
| 7 | GND2 | GND | Ground |
| 8 | D0N | Output | DSI_TX1_D0N |
| 9 | D0P | Output | DSI_TX1_D0P |
| 10 | GND3 | GND | Ground |
| 11 | D1N | Output | DSI_TX1_D1N |
| 12 | D1P | Output | DSI_TX1_D1P |
| 13 | GND4 | GND | Ground |
| 14 | CLKN | Output | DSI_TX1_CLKN |
| 15 | CLKP | Output | DSI_TX1_CLKP |
| 16 | GND5 | GND | Ground |
| 17 | D2N | Output | DSI_TX1_D2N |
| 18 | D2P | Output | DSI_TX1_D2P |
| 19 | GND6 | GND | Ground |
| 20 | D3N | Output | DSI_TX1_D3N |
| 21 | D3P | Output | DSI_TX1_D3P |
| 22 | GND7 | GND | Ground |
| 23 | NC | NC | NC |
| 24 | NC1 | NC1 | NC1 |
| 25 | GND8 | GND | Ground |
| 26 | NC2 | NC | NC |
| 27 | PWMO | NC | NC |
| 28 | NC4 | NC | NC |
| 29 | VCL | NC | NC |
| 30 | GND | GND | Ground |
| 31 | LED- | LED cathode | LED cathode |
| 32 | LED- | LED cathode | LED cathode |
| 33 | NC5 | NC | NC |
| 34 | NC6 | NC | NC |
| 35 | AVEE | NC | NC |
| 36 | NC7 | NC | NC |
| 37 | NC8 | NC | NC |
| 38 | AVDD3 | NC | NC |
| 39 | LED+ | LED anode | LED anode |
| 40 | LED+ | LED anode | LED anode |
Power and PoE
3.1 PoE port — PH2.0-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | POE1 | PoE | PoE 1 |
| 2 | POE2 | PoE | PoE 2 |
| 3 | POE3 | PoE | PoE 3 |
| 4 | POE4 | PoE | PoE 4 |
3.9 DC-in port — PH2.0-4P
Accepts 5–12 V.
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | GND | GND | Ground |
| 3 | DC in | Power in | VCC in 5/12V |
| 4 | DC in | Power in | VCC in 5/12V |
3.8 RTC port — PH1.25-2P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | BAT+ | BAT+ |
| 2 | GND | BAT- | BAT- |
Serial ports
The RS232 header is driven through the standard serial interface — open the
device node listed. The device API (ItempApiPub) does not handle UART I/O; it
covers power, display, GPIO,
network and kiosk.
3.7 RS232 port — PH1.25-4P → /dev/ttyS9
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | Power out | 3.3V |
| 2 | TX | I/O | ttyS9 — UART TX |
| 3 | RX | I/O | ttyS9 — UART RX |
| 4 | GND | GND | Ground |
USB ports
Three internal USB headers, identical pinout (PH1.25-4P).
3.3 USB1 · USB2 · USB3 — PH1.25-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | Power out | 5V |
| 2 | DM | I/O | USB D− |
| 3 | DP | I/O | USB D+ |
| 4 | GND | GND | Ground |
Audio
3.6 Speaker port — PH1.25-4P
Stereo output (two channels).
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | SPK- | Output | Left negative |
| 2 | SPK+ | Output | Left positive |
| 3 | SPK- | Output | Right negative |
| 4 | SPK+ | Output | Right positive |
LED, IR and control
3.5 IR + LED port — PH1.25-5P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | IR | IR | IR in |
| 2 | GND | GND | Ground |
| 3 | VCC | VCC | 3.3V |
| 4 | LED_G | LED green | LED green |
| 5 | LED_R | LED red | LED red |
GPIO
These are the pins the GPIO API drives. The SDK names
(GPIO_4C4, GPIO_1B0, GPIO_1B1) match the Define column below.
3.2 GPIO port — PH1.25-5P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | Power key | I/O | Power key |
| 3 | GPIO_4C4 | I/O | GPIO_4C4 |
| 4 | GPIO_1B0 | I/O | GPIO_1B0 |
| 5 | GPIO_1B1 | I/O | GPIO_1B1 |
See GPIO for reading and driving these lines from code.
Touch panel
3.11 TP I2C port — 10-pin
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | GND | GND | Ground |
| 3 | VCC | VCC | 3.3V |
| 4 | SDA | SDA | I2C data |
| 5 | SCL | SCL | I2C clock |
| 6 | GND | GND | Ground |
| 7 | INT | INT | Interrupt |
| 8 | RST | Reset | Reset |
| 9 | GND | GND | Ground |
| 10 | GND | GND | Ground |
Electrical specification
| Parameter | Min | Typical | Max | Notes |
|---|---|---|---|---|
| Power supply voltage | 5V | 12V | — | |
| Ripple voltage | — | — | 65 mV | |
| Power supply current | — | 2 A | — | Depends on screen size |
| Power consumption | — | 24 W | — | Depends on screen size |
API reference
The device API (power scheduling, GPIO, display, network, kiosk lockdown) is documented under ItempApi reference. The serial port above is driven through the standard Android serial interface.
Downloads
Schematic, mechanical drawing and firmware image are on the KTM-MS68 support page.