KTM-MS66
Ultra-compact RK3566 development board for embedded signage. MIPI display with integrated touch, Mini-HDMI out, Type-C and a battery/RTC input on a 68 × 65 mm, 12 W board.
Flashing, the firmware API and the guides apply to every board. This page covers what is specific to the KTM-MS66: its connectors, pin assignments and electrical limits.
Connector map
The KTM-MS66 is a round board; the map below places each connector on the nearest edge of a schematic rectangle.
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 |
| CPU | Rockchip RK3566, quad-core ARM Cortex-A55 |
| DDR | LPDDR4 2 GB |
| Flash | eMMC 5.0, 8 GB (16 GB optional) |
| Wi-Fi | 802.11 a/b/g/n/ac, 2×2 MIMO, dual 2.4 / 5 GHz |
| Ethernet | RJ45 gigabit (1000 M) |
| Screen interface | LVDS, EDP |
| HDMI | HDMI 2.0a out (Mini HDMI), 4K |
| Type-C | USB 2.0 Type-C |
| RTC | Yes — with scheduled power on/off |
| Camera | Via USB |
This datasheet appears partly templated from an RK3399 sibling board. The description text names the SoC "RK3399" (the specification table's RK3566 is correct), and the specification lists LVDS/EDP and gigabit Ethernet, but the only display connector fitted is MIPI (§3.8) and no RJ45 is broken out on the documented headers. Confirm the board's actual capabilities with us.
Power: DC 12 V / 1 A via the 12V-in header (§3.1); current depends on screen size.
Internal expansion: 12V-in, battery, RTC, USB-TTL, TTL, USB, MIPI (with integrated touch) and a touch I2C header.
Board dimensions
| Size | 68 mm × 65 mm |
| Thickness | 4.0 mm |
| Top clearance | 1.6 mm |
| Bottom clearance | 3.0 mm |
Serial ports at a glance
Two TTL UART headers are driven through the standard serial interface. The
datasheet does not give a /dev/ttyS* node for them.
| Port | Device node | Type |
|---|---|---|
| USB-TTL (§3.3) | — | UART (TTL) |
| TTL (§3.5) | — | UART (TTL) |
The device nodes are not specified in the datasheet. Confirm on your board with
ls /dev/ttyS* or contact us. See the
firmware API overview for how the device API drives the board
(power scheduling, GPIO, display, network, kiosk lockdown).
Display port
3.8 MIPI port — FPC 0.5 mm, 30-pin
Touch (pins 25–29) and backlight LED (pins 1–3) are integrated into this connector.
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | LEDA | LED anode | BL-LED-VCC + |
| 2–3 | LEDK- | LED cathode | BL-LED-VCC − |
| 4–5 | VCC | Power in | 3.3V |
| 6 | Mipi-RST_L | Reset | Reset |
| 7–8 | NC | NC | NC |
| 9 | GND | GND | Ground |
| 10 | MIPI_D0P | TX-D0P | Difference data, channel 0 |
| 11 | MIPI_D0N | TX-D0N | Difference data, channel 0 |
| 12 | GND | GND | Ground |
| 13 | MIPI_D1P | TX-D1P | Difference data, channel 1 |
| 14 | MIPI_D1N | TX-D1N | Difference data, channel 1 |
| 15 | GND | GND | Ground |
| 16 | MIPI_CLKP | TX_CLKP | Sampling clock |
| 17 | MIPI_CLKN | TX_CLKN | Sampling clock |
| 18 | GND | GND | Ground |
| 19 | MIPI_D2P | TX-D2P | Difference data, channel 2 |
| 20 | MIPI_D2N | TX-D2N | Difference data, channel 2 |
| 21 | GND | GND | Ground |
| 22 | MIPI_D3P | TX-D3P | Difference data, channel 3 |
| 23 | MIPI_D3N | TX-D3N | Difference data, channel 3 |
| 24 | GND | GND | Ground |
| 25 | INT | INT | Interrupt |
| 26 | SDA | SDA | I2C data |
| 27 | SCL | SCL | I2C clock |
| 28 | RST | RST | Reset |
| 29 | TpVCC | Power in | 3.3V |
| 30 | GND | GND | Ground |
Power
3.1 VCC 12V-in power port — 1.25-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | GND | GND | Ground |
| 2 | GND | GND | Ground |
| 3 | 12V | Power in | 12V |
| 4 | 12V | Power in | 12V |
3.2 Battery power port — 1.25-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | BAT- | Battery- | — |
| 2 | BAT- | Battery- | — |
| 3 | BAT+ | Battery+ | 3.0–4.2V |
| 4 | BAT+ | Battery+ | 3.0–4.2V |
3.4 RTC port — 1.25-2P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | Bat+ | Bat+ | 3.0V |
| 2 | GND | GND | Ground |
Serial ports
The TTL UART headers are driven through the standard serial interface. The device
API (ItempApiPub) does not handle UART I/O; it covers power,
display, GPIO, network and
kiosk.
3.3 USB-TTL port — 1.25-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | Power out | 5V |
| 2 | RX | RX | UART0 RX |
| 3 | TX | TX | UART0 TX |
| 4 | GND | GND | Ground |
3.5 TTL port — 1.25-4P
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | Power out | 5V |
| 2 | RX | I/O | UART0 RX |
| 3 | TX | I/O | UART0 TX |
| 4 | GND | GND | Ground |
USB port
3.6 USB port — 1.25-4P
The datasheet lists pin 4 as VCC 3.3V rather than a ground. A USB header
normally needs a ground return — verify pin 4 on your board before wiring.
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | VCC | Power out | 5V |
| 2 | DM | I/O | USB D− |
| 3 | DP | I/O | USB D+ |
| 4 | VCC | Power out | 3.3V |
Touch panel
3.7 I2S port — FPC 0.5 mm, 10-pin
The datasheet titles this connector "I2S", but its pins (SCL, SDA, RST, INT) are a touch-panel I2C interface, not an I2S audio bus (same as several other boards in this range). Treat it as touch-panel I2C and verify with us before wiring an I2S device to it.
| Pin | Define | Attribute | Description |
|---|---|---|---|
| 1 | SCL | SCL | I2C clock |
| 2 | SDA | SDA | I2C data |
| 3 | VCC | VCC | 3.3V |
| 4 | RST | Reset | Reset |
| 5 | INT | INT | Interrupt |
| 6 | GND | GND | Ground |
Other interfaces
3.9 Other ports
| Interface | Detail |
|---|---|
| Type-C | USB 2.0 |
| Micro USB | OTG |
| Mini HDMI | HDMI 2.0a |
Electrical specification
| Parameter | Min | Typical | Max | Notes |
|---|---|---|---|---|
| Power supply voltage | — | 12V | — | |
| Ripple voltage | — | — | 85 mV | |
| Power supply current | — | 1 A | — | Depends on screen size |
| Power consumption | — | 12 W | — | Depends on screen size |
API reference
The device API (power scheduling, GPIO, display, network, kiosk lockdown) is documented under ItempApi reference. The serial ports above are driven through the standard Android serial interface.
Downloads
Schematic, mechanical drawing and firmware image are on the KTM-MS66 support page.