Version 1.0

Product Overview

The fanless embedded PC CS-A55-BOX (PN: CS-RK3568-BOX) is a Cortex®-A55 series high-quality industrial PC. Thanks to the fanless design, it is stable and reliable in client terminal, multimedia and other industry applications.

The offered CPU consumes very little power, around 4.35W (max). From the ground-up, the CPU is built for low power consumption. As such, it is best suited for mobile and power-constrained industrial or field applications. A specially designed aluminum alloy housing with fins for increased heat dissipation serves as a passive cooler, eliminating the need for built-in fans. The fanless design reduces noise, as well as the maintenance costs and efforts, leading to increased reliability at the same time.

The CS-A55-BOX Industrial PC is based around the powerful RK3568 System on Chip (SoC), powered by the Rockchip RK3568 low-power processor which integrates a quad-core Cortex®-A55 2.0GHz processor.

The RK3568 supports multi-format video decoders and has a high-performance 2GB LPDDR4 RAM capable of sustaining demanding memory bandwidths. It also provides a complete set of peripheral interfaces.

Ordering Options

Chipsee products can be customized during the ordering process. The product will be shipped with the pre-installed factory defaults if no extra requirements are specified. The table in the Hardware Features section provides information about the default options bundled with the product.


You can order the CS-A55-BOX from the official Chipsee Store or from your nearest distributor.

Operating System

This product comes with a pre-installed OS of your choice. Please see the list below for the supported OSes, which can also be obtained from the Software Documentation section, along with the detailed installation instructions.

  • Debian 11

  • Android 11

  • Buildroot Linux Qt 5.15


The Software Documentation section provides a detailed instruction on how to install different OSes on your own. However, bear in mind that Chipsee can’t take the responsibility of inadequate installation procedure. If you “brick” your device, please contact Chipsee Technical Support at support@chipsee.com for further assistance

Optional Features

The CS-A55-BOX Industrial PC does not include 4G/LTE module by default. The module is optional and can be selected at the Chipsee store during the ordering process.


Installation, repair, and maintenance tasks should be performed by trained personnel only. Chipsee does not bear any responsibility for damage caused by inadequate handling of the product.

Hardware Features

The CS-A55-BOX Industrial PC offers a broad range of performance and connectivity options for scalable integration, providing expandability according to future needs. Some of the key features are listed in the table below.

Table 184 Key Features



Rockchip RK3568, Quad-core Cortex-A55 (2.0GHz)








TF Card, Supports up to 128GB SDHC




1 x HDMI-D (Micro-HDMI) Out




1 x USB 2.0 HOST, 1 x USB 3.0 HOST, 1 x USB Type-C


2 x RJ45, GbE


Supported for 1 x optional POE RJ45


3.5mm Audio In/Out Connector, 2W Internal Speaker




High accuracy RTC with farad capacitor, can work 1 week after power off (default). High accuracy RTC with lithium coin battery, can work 3 years after power off (optional).


default 2 x RS232 (Optional 6 x RS232 at most, include 1 debug port)1


default 3 x RS485 at most1


default 2 x CAN


8 Channels Isolated IO, 4 x Input and 4 x Output


Integrated WiFi/BT Module


Supported, Optional

Power Input

From 6V to 36V


290mA (max) at 15V

Power Consumption

4.35W (max)

Working Temperature

From 0°C to +60°C


Android 11, Debian11, Buildroot Linux Qt 5.15


CS-A55-BOX (PN: CS-RK3568-BOX): 209 x 125 x 37.3mm


CS-A55-BOX (PN: CS-RK3568-BOX): 900g


CS-A55-BOX (PN: CS-RK3568-BOX): Rear, VESA


This product has 6 x UART channels in total. The default configuration is 2 x RS232 and 3 x RS485, include 1 debug port. UART can be swapped between RS232 and RS485 modes easily, if you need a different RS232/RS485 configuration, please get in touch with the Chipsee Technical Support at support@chipsee.com

Power Input

The CS-A55-BOX Industrial PC can be powered by a wide range of input voltages: From 6V to 36V DC.

There are two DC input interfaces on this device: a 3-pin, 3.81mm terminal, and a 2.1mm I.D x 5.5mm O.D x 9.5mm DC connector.


Power Input

Note that the “+” sign represents the positive power input, and it is printed both at the casing and as a silk-screen on a PCB of the embedded version. The “-” terminal is shorted to the ground.

Table 185 Power Connector

Power Input Definition

Pin Number



Pin 1

Positive Input

DC Power Positive Terminal

Pin 2

Negative Input

DC Power Negative Terminal

Pin 3


Power System Ground


The system ground “G” is connected to power negative “-” on board.

For a proper DC power connector, refer to the figure below.


DC Jack


There are many connectivity options available on the CS-A55-BOX industrial PC. It has 1 x USB 2.0 HOST, 1 x USB 3.0 HOST, 1 x USB Type-C, 2 x RJ45, GbE (RJ45) Ethernet connector supporting up to 1 Gbps, and 5 x UART terminals (RS232/RS485/CAN).


The serial communication interfaces (RS485, RS232, and CAN) are routed to a 16-pin 3.81mm terminal, as illustrated on the figure below.


RS232 RS485 CAN Pins

The table below offers more detailed description of every pin and its definition:

Table 186 Connectivity Section

RS232 / RS485 / CAN Pin Definition:

Pin Number



Pin 16


CAN H signal

Pin 15


CAN L signal

Pin 14


CAN H signal

Pin 13


CAN L signal

Pin 12


CPU UART5, RS485 –(B) signal

Pin 11


CPU UART5, RS485 +(A) signal

Pin 10


CPU UART4, RS485 –(B) signal

Pin 9


CPU UART4, RS485 +(A) signal

Pin 8


CPU UART3, RS485 –(B) signal

Pin 7


CPU UART3, RS485 +(A) signal

Pin 6


CPU UART0, RS232 RXD signal

Pin 5


CPU UART0, RS232 TXD signal

Pin 4


CPU UART2, RS232 RXD signal, Debug Port

Pin 3


CPU UART2, RS232 TXD signal Debug Port

Pin 2


System Ground

Pin 1


System +5V Power Output, No more than 1A Current output


  1. RS485_3,RS485_4 and RS485_5 can control the input and output direction automatically. There’s no need to control it from within the software.

  2. The 120Ω match resistor for the RS485 is mounted by default.

  3. The 120Ω match resistor for the CAN bus is NOT mounted by default.

USB Connectors

There are 2 x USB HOST and 1 x USB DEVICE (for flashing OS) ports onboard: 1 x USB 2.0 HOST, 1 x USB 3.0 HOST, 1 x USB Type-C , as shown in the figures below.


USB 2.0 HOST Port (embedded / enclosed PC version)


USB 3.0 HOST Port (embedded / enclosed PC version)


USB Type-C Port (embedded / enclosed PC version)


Be careful not to touch surrounding electronic components accidentally while plugging USB devices into the embedded IPC version.

LAN Connectors

LAN (RJ45) connector provides 2 x RJ45 Ethernet (including 1 x optional POE port: LAN0) Ethernet connectivity over standardized Ethernet cables as shown in the figure below. The integrated Ethernet interface supports up to 1 Gbps data throughput.


RJ45 LAN Connector


Use CAT5 or better cables to achieve full data throughput over maximum distance defined by the 1000BASE-T standard (100m).

WiFi & BT Module

The CS-A55-BOX Industrial PC is equipped with the popular Realtek RTL8821CS WiFi/BT module which supports BT/BLE 2.1/3.0/4.2, as well as 802.11ac/abgn 433Mbps 2.4/5.8 GHz Wireless LAN (WLAN).


Figure 650: RTL8821CS WiFi/BT Module

The CS-A55-BOX includes an SMA connector for an external WiFi/BT antenna, as illustrated in the figure below.


WiFi+BT Antenna SMA

4G/LTE Module

The CS-A55-BOX Industrial PC is equipped with a mini-PCIe connector that can connect a 4G/LTE module. The customer will also need a SIM Card Holder and a 4G/LTE Antenna Connector to ensure 4G/LTE works on the CS-A55-BOX. SIM card does NOT support hot plug. Power off before inserting or removing SIM card.


Figure 651: mini-PCIe Connector & 4G Module


Figure 652: SIM Card Holder & 4G Antenna


SIM Card Direction


The product does not come shipped with the 4G/LTE module by default. The customer can choose the 4G/LTE module option when placing an order, we will install all the necessary components.

TF Card & SIM Card Slot

The CS-A55-BOX Industrial PC features 1 x TF Card (micro SD) slot and 1 x SIM Card slot. TF Card can address up to 128GB of storage.


TF (micro SD) Card & SIM Card Slot


The product does not come shipped with the TF Card by default.

Audio Connectors

The CS-A55-BOX Industrial PC features some audio peripherals. It has a 3.5mm audio input/output jack, an internal speaker, as well as a small buzzer.


Audio Connector (enclosed PC version)

The miniature 2W embedded speaker is handy for audio reproduction, the small buzzer can play alarm/notification sounds.


Figure 653: 2W Micro Speaker and Buzzer


By plugging in the headphone cable, the internal speaker will be disabled automatically.

HDMI Connector

The CS-A55-BOX Industrial PC is equipped with 1 x HDMI-D (Micro-HDMI) Out port. The HDMI connector allows connecting an additional (external) monitor. HDMI output resolution can be configured by the software.


HDMI Connector

PROG Button

The CS-A55-BOX Industrial PC has one button on the board marked as PROG, as shown in the figure below.
When the button is pressed before powering up, the CS-A55-BOX will enter MASKROM mode. In this mode you can use a USB Type-C cable to upgrade its operating system. You can use this feature to flash another OS to the internal eMMC.

When the button is not pressed before and during power up, the CS-A55-BOX will boot normally.

There is no need to press the button during regular operation. However, if you need to flash the OS in MASKROM mode, the button will be used. Please refer to the software documents for more information.


PROG Button


The CS-A55-BOX Industrial PC features a 10-pin 3.81 mm terminal that provides 8 x opto-isolated GPIO pins, of which 4 x are output, and 4 x are input pins. The 10-pin terminal also includes an isolated PSU input in the range of 5 to 24 VDC. The exact pinout is given in follow table.

The GPIO HIGH output level corresponds to the voltage connected at the Isolated Power Input, while the GPIO LOW output level corresponds to the isolated Ground Input. Each GPIO output can drive loads up to 500mA, enough to drive various applications directly, such as relays or solenoid valves.


GPIO Terminal (enclosed PC version)


Isolated GPIO reduced schematic

Table 187 GPIO Pinout

GPIO Pin Definition:

Pin Number


Pin 1

Isolated Power Input2

Pin 2

Isolated Ground Input

Pin 3


Pin 4


Pin 5


Pin 6


Pin 7


Pin 8


Pin 9


Pin 10


If the isolation is not a requirement, it is possible to use a non-isolated PSU instead.
It is also possible to use the onboard 5V power supply: it can be re-routed to the Isolated Power Input pin by populating R251 and R247 PCB footprints with 0Ω resistors.
Note that in this case, the Isolated Power Input pin will become an output for the onboard 5V power supply.

Mounting Procedure

You can mount CS-A55-BOX with VESA mounting (guide): 75 x 75 mm, 4 x M4 (6mm) screws.

You can also mount CS-A55-BOX with rear mounting method (guide).


Please make sure the display is not exposed to high pressure when mounting into an enclosure.

Mechanical Specifications

For CS-A55-BOX, the outer mechanical dimensions are 209 x 125 x 37.3mm (W x L x H).

Please refer to the technical drawing in the figure below for details related to the specific product measurements.


Figure 654: CS-A55-BOX Technical Drawing


This document is provided strictly for informational purposes. Its contents are subject to change without notice. Chipsee assumes no responsibility for any errors that may occur in this document. Furthermore, Chipsee reserves the right to alter the hardware, software, and/or specifications set forth herein at any time without prior notice and undertakes no obligation to update the information contained in this document.

While every effort has been made to ensure the accuracy of the information contained herein, this document is not guaranteed to be error-free. Further, it does not offer any warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document.

Despite our best efforts to maintain the accuracy of the information in this document, we assume no responsibility for errors or omissions, nor for damages resulting from the use of the information herein. Please note that Chipsee products are not authorized for use as critical components in life support devices or systems.

Technical Support

If you encounter any difficulties or have questions related to this document, we encourage you to refer to our other documentation for potential solutions. If you cannot find the solution you’re looking for, feel free to contact us. Please email Chipsee Technical Support at support@chipsee.com, providing all relevant information. We value your queries and suggestions and are committed to providing you with the assistance you require.