Hardware Interfaces and Design

Hardware Overview

The Radxa E24C is a compact, high-performance network computer powered by the Rockchip RK3528A processor, designed for routing, edge networking, and industrial applications. It achieves an optimal balance between performance, connectivity, and reliability.

This document details the hardware interfaces, connection methods, and application recommendations for the E24C to help you maximize the device's performance.

Chip Architecture

The RK3528A is a high-performance processor from Rockchip, featuring high performance, low power consumption, and cost-effectiveness.

• Powerful Processing: Quad-core ARM Cortex-A53
• Networking Capabilities: Supports multiple Gigabit network interfaces, optimized for networking applications
• Diverse Interfaces: Supports various high-speed interfaces including PCIe, USB 3.0, and HDMI 2.1

E24C Internal Chip Architecture Diagram

System Architecture

The E24C adopts a compact and efficient hardware design, integrating multiple interfaces and functions on a single board.

E24C System Internal Architecture and Component Connection Diagram

Hardware Interfaces

tip

For detailed hardware interface pinouts of Radxa E24C, refer to the Hardware Schematic

E24C Bare Board Interfaces

No.	Description	Qty
①	Power Input: DC5525	1
②	Onboard eMMC	1
③	USB 2.0 Type-C Port (OTG + UART Debug)	1
④	User Button	1
⑤	USB 2.0 Type-A Ports	3
⑥	RTC Battery Connector	1
⑦	MicroSD Card Slot	1
⑧	GPIO: 14-pin Expansion Header	1
⑨	LED Indicators (1x Power, 4x Ethernet)	5
⑩	Power Button	1
⑪	Fan Header	1
⑫	Maskrom Button	1
⑬	Gigabit Ethernet Ports	4
⑭	HDMI 2.1 Output	1
⑮	M.2 NVMe SSD Slot	1

MicroSD Card Slot

The E24C features a MicroSD card slot, which can be used for storing system data, system images, and system configurations.

PIN	Name	Function Description
1	SDMMC_D2	SD card data line 2
2	SDMMC_D3	SD card data line 3
3	SDMMC_CMD	SD card command line
4	VCC_3V3	3.3V power supply
5	SDMMC_CLK	SD card clock signal
6	GND	Ground
7	SDMMC_D0	SD card data line 0
8	SDMMC_D1	SD card data line 1
9	SDMMC_DETN	SD card insertion detection
10	GND	Ground
11	GND	Ground
12	GND	Ground
13	GND	Ground

Usage Guide

• Supported Card Types: Compatible with MicroSD/MicroSDHC/MicroSDXC memory cards
• Recommended Specifications: Class 10/UHS-I or higher recommended for better performance
• Maximum Capacity: Theoretically supports up to 2TB MicroSDXC cards, tested with 512GB cards

Main Application Scenarios

• System Boot: E24C can boot the operating system from a MicroSD card, which is the most common usage
• Data Storage: Can be used to expand storage space when the system is already running (e.g., when booted from eMMC)
• System Backup: Can be used to back up the current system and data

tip

For production environments or systems requiring 24/7 operation, it is recommended to use eMMC or M.2 SSD as the primary storage and boot device, as they provide better stability and read/write endurance. MicroSD cards are suitable for temporary storage and development/testing scenarios.

USB Interfaces

E24C provides two different types of USB interfaces: USB 2.0 Type-C and USB 2.0 Type-A.

USB 2.0 Type-C

Serves as a data transfer interface, supporting USB 2.0 OTG data transfer and serial debugging, with data transfer rates up to 480Mbps.

USB 2.0 Type-A

Three USB 2.0 Type-A interfaces, supporting data transfer rates up to 480Mbps.

PIN	Name	Description
1	VCC5V0_USB	5V Power Output, max 500mA
2	USB2_HOST_DM	USB 2.0 Data-
3	USB2_HOST_DP	USB 2.0 Data+
4	GND	Ground

Usage Recommendations:

• Input devices like mice and keyboards
• Low-bandwidth peripherals (printers, scanners, etc.)
• External devices supporting USB 2.0

HDMI Interface

E24C features a standard HDMI 2.1 interface supporting up to 4K video output, suitable for connecting to external displays, TVs, and other devices.

PIN	Name	Description
1	HDMI_TX2+	HDMI High-Speed Data Lane 2+
2	GND	Ground
3	HDMI_TX2-	HDMI High-Speed Data Lane 2-
4	HDMI_TX1+	HDMI High-Speed Data Lane 1+
5	GND	Ground
6	HDMI_TX1-	HDMI High-Speed Data Lane 1-
7	HDMI_TX0+	HDMI High-Speed Data Lane 0+
8	GND	Ground
9	HDMI_TX0-	HDMI High-Speed Data Lane 0-
10	HDMI_TXC+	HDMI Clock+
11	GND	Ground
12	HDMI_TXC-	HDMI Clock-
13	HDMI_CEC	Consumer Electronics Control for device control
14	NC	No Connection
15	HDMI_SCL	DDC Clock for EDID information
16	HDMI_SDA	DDC Data for EDID information
17	GND	Ground
18	VCC5V0_HDMI	5V Power Output
19	HDMI_HPD	Hot Plug Detect Signal

Gigabit Ethernet Interface

The E24C is equipped with 4 Gigabit Ethernet ports, which are the core functional components of the product, supporting various network application scenarios.

PIN	Name	Description
1	ETH_TXP	Gigabit Ethernet Transmit+
2	ETH_TXN	Gigabit Ethernet Transmit-
3	ETH_RXP	Gigabit Ethernet Receive+
4	NC	Not Connected
5	NC	Not Connected
6	ETH_RXN	Gigabit Ethernet Receive-
7	NC	Not Connected
8	NC	Not Connected

Gigabit Network Controller

The Gigabit network interface of E24C is driven by the network controller integrated in the Rockchip RK3528A SoC, with main features including:

• Full-Duplex Gigabit Ethernet: Each port supports 10/100/1000 Mbps speeds
• MDI/MDIX Auto-Detection: Automatically identifies straight-through and crossover cables
• IEEE 802.3 Compliance: Supports standard Ethernet protocols
• Hardware Flow Control: Supports IEEE 802.3x flow control
• Internal MAC Addresses: Each port is assigned an independent MAC address

Network Configuration Scenarios

The four Gigabit Ethernet ports allow flexible configuration of various network topologies:

1. Multi-WAN Router Configuration

Multiple ports can be configured as WAN interfaces to achieve:

• Multi-line load balancing
• Link aggregation
• Multi-ISP backup connections

2. Network Switch Configuration

Configure all ports in switch mode for:

• Network segmentation (VLAN)
• QoS priority control
• Port mirroring and monitoring

3. Combined Mode

The most common configuration: 1 WAN + 3 LAN ports:

• 1 port connects to the upstream router/modem
• 3 ports for internal network device connections

Usage Recommendations

• Use CAT 5e or higher specification network cables for full Gigabit performance
• Multi-WAN configuration requires specialized routing software support, such as iStoreOS or OpenWrt
• Pay attention to heat dissipation when running high-traffic network applications

tip

For applications requiring powerful network performance (such as enterprise routing, gateways, etc.), you can configure Port Bonding to increase bandwidth and reliability. These advanced features can be easily configured in iStoreOS or OpenWrt.

M.2 M Key Interface

PIN	Name
1	GND
2	VCC3V3_PCIE
3	GND
4	VCC3V3_PCIE
5	GND
6	NC
7	GND
8	NC
9	GND
10	NC
11	GND
12	NC
13	GND
14	NC
15	GND
16	NC
17	GND
18	NC
19	GND
20	NC
21	GND
22	NC
23	GND
24	NC
25	GND
26	NC
27	GND
28	NC
29	GND
30	NC
31	GND
32	NC
33	GND
34	NC
35	GND
36	NC
37	GND
38	NC
39	VCC3V3_PCIE
40	NC
41	VCC3V3_PCIE
42	NC
43	GND
44	NC
45	NC
46	NC
47	GND
48	NC
49	GND
50	PCIE_CLKREQ_N
51	GND
52	PCIE_WAKE_N
53	GND
54	PCIE_REFCLK_P
55	PCIE_REFCLK_N
56	NC
57	GND
58	PCIE_RX_N
59	PCIE_RX_P
60	GND
61	GND
62	PCIE_TX_N
63	PCIE_TX_P
64	GND
65	GND
66	NC
67	NC
68	PCIE_RST_N
69	GND
70	NC
71	GND
72	NC
73	GND
74	NC
75	GND

Fan Interface (2-Pin 1.25mm)

PIN	Name
1	PWM
2	GND

RTC Battery Interface (2-Pin 1.25mm)

PIN	Name
1	VCC3V0_RTC
2	GND

14-Pin GPIO Interface (0.1"/2.54mm)

PIN	Name	Function
1	VCC5V0	5V Power Output
2	VCC5V0	5V Power Output
3	VCC3V3	3.3V Power Output
4	GND	Ground
5	GPIO0	SPI_CLK
6	GPIO1	SPI_MOSI
7	GPIO2	SPI_MISO
8	GPIO3	SPI_CS
9	GPIO4	UART_TX
10	GPIO5	UART_RX
11	GPIO6	I2C_SCL
12	GPIO7	I2C_SDA
13	GPIO8	General Purpose
14	GND	Ground