Dual ETH Quad RS485 Base Board (B) for Raspberry Pi Compute Module 4, Gigabit Ethernet, 4CH Isolated RS485 (WS-21666)

Dual ETH Quad RS485 Base Board (B) For Raspberry Pi Compute Module 4, Gigabit Ethernet, 4CH Isolated RS485, USB2.0

Dual ETH Quad RS485 Base Board For CM4

Designed For Raspberry Pi Compute Module 4

 

Specifications

CM4 SOCKET	suitable for all variants of Compute Module 4
NETWORKING	Gigabit Ethernet RJ45 connector, 100M Ethernet RJ45 connector
CONNECTOR	Isolated RS485 × 4, Power screw terminal × 1
USB	USB 2.0 Type A × 2
CAMERA	MIPI CSI-2 port × 2 (15pin 1.0mm FPC connector)
VIDEO	HDMI port × 1, supports 4K 30fps output
RTC	Real-time clock with battery socket and ability to wake Compute Module 4
STORAGE	MicroSD card socket for Compute Module 4 Lite (without eMMC) variants
FAN HEADER	allows speed adjustment, 5V
INDICATOR	Power indicator × 1, CM4 status indicator × 1,  User LED × 2, RS485 communication indicator × 8
POWER INPUT	7-36V
DIMENSIONS	93.6 × 108.8mm

Connecting With Compute Module 4

Standard CM4 Socket And Suitable For All Variants Of Compute Module 4

More Rich Interfaces

Various Interfaces Including: Dual ETH / RS485 / CSI / FAN / HDMI / Micro SD / USB

Application Examples

Suitable For Raspberry Pi Applications Requiring Multi-Channel RS485 Communication Or Other Industrial Context

for reference only, CM4, display, and cameras are NOT included.

What's On Board

1. CM4 socket
   suitable for all variants of Compute Module 4
2. IO-VREF
   Set the CM4 IO logic level as 3.3V (default) or 1.8V
3. RTC-12C: 12C bus selection for RTC
   Can choose SDA0 & SCLO (default) or GPIO2 & GPIO3
4. RTC INT: RTC interrupt pin select
   D16: Use GPIO16 to receive interrupt signal when RTC interruption (default)
   GL-EN: CM4 powerdown on RTC interruption
   PI-RUN: CM4 will reboot on RTC interruption
5. SYSTEM: System function configuration
   WP-DIS: Prevent EEPROM from being overwritten
   BT-DIS: Disable Bluetooth function, for CM4 with antenna variant ONLY
   WIFI-DIS: Disable WiFi function, for CM4 with antenna variant ONLY
6. Boot
   ON: CM4 will be booted from USB-C interface
   OFF: CM4 will be booted from eMMC or Micro SD card
7. PWR & USB
   When the BOOT switch is "ON", can be used as the USB programming or DC power supply port
   When the BOOT switch is "OFF", only used as the DC power supply port
8. HDMI0
   HDMI port, supports 4K 30fps output
9. USB
   2x USB 2.0, for connecting sorts of USB devices
10. ETHERNET0
    CM4 original Gigabit RJ45 ETH
11. ETHERNET1
    USB extended 100M ETH
12. CAM0 & CAM1
    2x MIPI CSI camera ports
13. Buzzer
    GPIO22 control

 

14. FAN
    4-pin FAN header, only supports 5V FAN, allows PWM speed adjustment (GPIO18 control, speed measurement is not supported)
15. RTC battery socket
    Supports CR1220 button cell
16. RS485 TX/RX indicator
    TXn: TX indicator for channel n
    RXn: RX indicator for channel n
17. User LED
    USER0: GPIO20 control
    USER1: GPIO26 control
18. PWR
    Raspberry Pi power indicator
19. ACT
    Raspberry Pi working status indicator
20. DC 7~36V
    DC power supply interface
21. Power input terminal
    DC power supply terminal, supports 7~36V wide range power input
22. RS485 terminal
    4 x Isolated RS485 terminal with a spacing of 5.08mm
23. Jumper
    120R Balance Resistor Selection Jumper
24. RS485 operating mode selection
    Full-auto: automatic mode, easy for program operation but the load capacity is weak
    Semi-auto: semi-automatic mode, which requires manual TX/RX switching, with high reliability and strong load capacity
25. Encryption chip
    ATSHA204 encryption chip, providing multiple encryption to ensure data security and reliability
26. Micro SD card slot
    for connecting a Micro SD card with pre-burnt image (Lite variant ONLY)

Outline Dimensions

What's The Differences

CM4 BASE BOARD	INTERFACE COUNT AND SPECIFICATIONS
	POE	GIGABIT ETH	40PIN GPIO	PCIE	USB①	DSI	HDMI	CSI	RTC	FAN HEADER	POWER INPUT	FEATURES
MINI BASE A		×1	√	M.2 M	2.0×4	×1	×2	×2		5V	5V	mini size
MINI BASE B		×1	√	M.2 M	2.0×4	×1	×2	×2	√	5V	5V	mini size
BINOCULAR CAMERA		×1	√	M.2 M	2.0×4		×2				5V	dual 8MP cameras
DUAL GIGABIT ETH		×2	√		3.0×3	×1	×2	×2	√	5/12V	7-36V
IOT DUAL GIGABIT ETH		×2	√		3.0×2	×1	×2	×2	√	5/12V	5V	5G/4G support
IOT BASE	√	×1		Gen2×1	2.0×2	×2	×2	×2	√	5/12V	7-36V	5G/4G support RS232 RS485 ADC
POE BASE (B)	√	×1	√	Gen2×1	2.0×4	×2	×2	×2	√	5/12V	5V	RS232 RS485
POE BASE	√	×1	√		3.0×4	×2	×2	×2	√	5/12V	7-36V
RASPBERRY PI OFFICIAL	②	×1	√	Gen2×1	2.0×4	×2	×2	×2	√	12V	12V
WIRELESS BASE		×1		M.2 B / Mini-PCIe	2.0×3		×1	×1	√	5/12V	5V or 7-36V	5G/4G support RS485 CAN rail-mount
7″ ALL-IN-ONE		×1		M.2 M	2.0×4	used	×1	used	√	5/12V used	7-36V	touch screen camera speaker
NOTE	① USB 3.0 is equivalent to USB 3.2 Gen1 ② There's PoE header only on the Raspberry Pi official IO board without PoE circuit, that means additional PoE module is required for the official IO board to enable PoE feature.  Unless otherwise specified, the PoE feature here stands for integrating 802.3af-compliant PoE circuit (5V/2.5A).

Resources & Services

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WIKI: CM4-ETH-RS485-BASE-B