3012 CM4 5G Mini EN

Keywords

5G sub, Qualcomm, Unisoc, Quectel, Fibocom, Raspberry Pi OS, Ubuntu, OpenWrt

I. Introduction

The CM4_5G_Mini driver board adopts USB interfaces and is designed for compact and low-power applications. With size of only 40.2*58.4mm, it supports mainstream USB M.2 B-key 5G modules. It is compatible with 5G modules sized 52*30mm and features a reserved space of 42*30mm. Onboard original imported 5A current DC-DC power supply chip, PCB board adopts immersion gold process to ensure stable and reliable operation. The 5G module can stably achieve up to 310Mbps in USB2.0 mode, meeting the requirements of most application scenarios. The module can be directly mounted above the Raspberry Pi CM4/CM5.

The CM4_5G_Mini driver board comes in two versions: the standard version features USB 2.0, while the new version supports USB3.0 (with both onboard USB3.0 and USB2.0 ports). The new Version USB3.0 adds a 5V auxiliary power supply function. If the motherboard's USB port cannot provide sufficient power to the driver board, the auxiliary power interface can be used to independently supply power to the 5G module. We have conducted tests on 5G module models including Unisoc's FM650-CN and RM500U-CNV/EA, as well as Qualcomm's FM160-EAU, RM520N(530N)-GL/CN, and RM551E-GL. Our company's shipped 5G modules are pre-configured to work seamlessly with the Raspberry Pi OS and Ubuntu OS, requiring no additional drivers, dial-up setup, or manual configuration, they are automatically recognized upon connection. However, if customers purchase 5G modules on their own, they will need to handle the driver installation and configuration themselves.

II. Hardware Spec

1) Equipped with an original imported 5A high-current DC-DC power supply chip, powered and communicated through a USB port.

2) 1*USB M.2 B‑Key interface supporting 5G modules with dimensions of 30*52mm/30*42mm, also compatible with USB M.2 B interface 4G modules.

3) 1*onboard Nano SIM card.

4) 1*communication and power supply interface: USB port. The Version USB2.0 includes a USB-C port and a 1.25mm-4Pin connector, while the Version USB3.0 includes a USB 3.0-C port and a USB 2.0 (1.25mm-4Pin) connector. Only one of them can be used at a time.

5) 1*auxiliary 5V power supply interface, 2.54mm‑2P (only for Version USB3.0).

6) 2*LEDs: 1*Power LED and 1*Status LED.

7) Size: 40*(58.4+3.7)mm, compatible with Raspberry Pi CM4/CM5.

8) PCB with immersion gold process and RoHS compliant. PCB materials are UL certified, flame‑retardant rating 94V‑0.


Differences between the two versions	CM4 5G mini	CM4 5G mini_USB3.0
USB ports	USB2.0(USB-C和1.25mm-4P), choose one of two.	USB3.0(USB-C) and USB2.0(1.25mm-4P), choose one of two.
Auxiliary power supply interface	None	5V power supply, 2.54mm-2P

Model	RM500U-CNV	RM500U-EA
Band	5G NR: 3GPP Release 15/ Release 16 NSA/SA operation, Sub-6 GHz 5G NR NSA: n41/78/79 5G NR SA: n1/3/5/8/28A/41/77/78/79 *DL 44 MIMO: n1/28A/41/77/78/79 UL 22 MIMO:* n41/77/78/79 *DL 22 MIMO: n3/5/8 LTE Category: DL Cat 12, UL Cat 13 LTE-FDD: B1/3/5/8 LTE-TDD: B34/38/39/40/41 DL 22MIMO:* B1/3/5/8/34/38/39/40/41 WCDMA: B1/5/8	5G NR: 3GPP Release 15 NSA/SA operation, Sub-6 GHz 5G NR NSA: n1/3/7/28/38/40/41/77/78 5G NR SA: n1/3/5/7/8/20/28/38/40/41/66/77/78 *DL 44 MIMO: n1/3/7/28/38/40/41/66/77/78 UL 22 MIMO:* n38/40/41/77/78 *DL 22 MIMO: n5/8/20 LTE Category: DL Cat 12, UL Cat 13 LTE-FDD: B1/2/3/4/5/7/8/20/28/66 LTE-TDD: B38/40/41 DL 22MIMO:* B1/2/3/4/5/7/8/20/28/38/40/41/66 WCDMA: B1/2/5/8
Data	5G SA Sub-6: 2Gbps (DL)/1Gbps (UL) 5G NSA Sub-6: 2.2Gbps (DL)/575Mbps (UL) LTE: 600Mbps (DL)/150Mbps (UL) WCDMA: 42.2Mbps (DL)/11 Mbps (UL)	5G SA Sub-6: 2Gbps (DL)/1Gbps (UL) 5G NSA Sub-6: 2.6Gbps (DL)/650Mbps (UL) LTE: 600Mbps (DL)/150Mbps (UL) WCDMA: 42.2Mbps (DL)/11 Mbps (UL)
Temperature	-30℃ ~ +75℃

Model	RM520N-GL	RM530N-GL	RM551E-GL
Band	5G NR NSA: n1/2/3/5/7/8/12/13/14/ 20/25/28/29/30/38/40/41/48/66/70/ 71/77/78/79 5G NR SA: n1/2/3/5/7/8/12/13/14/ 18/20/ 25/26/28/29/30/38/40/41/ 48/66/70/71/75/76/77/78/79 LTE-FDD: B1/2/3/4/5/7/8/12/13/ 14/17/18/19/20/25/26/28/29/ 30/32/66/71 LTE-TDD: B34/38/39/40/41/42/43/48 LAA: B46 WCDMA: B1/2/4/5/8/19 GNSS (Optional): GPS/GLONASS/BD5/ Galileo/QZSS	5G NR NSA: n1/2/3/5/7/8/12/13/14/ 18/20/25/26/28/29/30/38/40/41/48/ 66/70/71/75/76/77/78/79/257/258/ 260/261 5G NR SA: n1/2/3/5/7/8/12/13/14/ 18/20/25/26/28/ 29/30/38/40/41/48/ 66/70/71/75/76/77/78/79 LTE-FDD: B1/2/3/4/5/7/8/12/13/ 14/17/18/19/20/25/26/28/29/30 /32/66/71 LTE-TDD: B34/38/39/40/41/42/ 43/48 LAA: B46 WCDMA: B1/2/4/5/8/19 GNSS (Optional): GPS/GLONASS/BD5/ Galileo/QZSS	5G NR NSA: n1/2/3/5/7/8/12/13/14/18/20/ 25/26/28/29(Rx)/30/38/40/41/48/53/66/70/ 71/75/76/77/78/79/92/94/257/258/260/261 5G NR SA: n1/2/3/5/7/8/12/13/14/18/20/25/ 26/28/29(Rx)/30/38/40/41/53/48/66/70/71/ 75/76/77/78/79/91/92/93/94/257/258/260/261 LTE-FDD: B1/2/3/4/5/7/8/12/13/14/17/18/ 19/20/25/26/28/29/30/32/66/70/71 LTE-TDD: B34/38/39/40/41/42/43/48/53 LAA: B46(Rx) WCDMA: B1/2/4/5/8/19 GNSS (Optional): GPS/GLONASS/BD5/ Galileo/QZSS
Data	5G SA Sub-6: 2.4Gbps (DL)/900Mbps (UL) 5G NSA Sub-6: 3.4Gbps (DL)/550Mbps (UL) LTE-FDD: 1.6Gbps (DL)/200Mbps (UL) WCDMA: 42Mbps (DL)/5.76Mbps(UL)	5G SA Sub-6: 2.4Gbps (DL)/900Mbps (UL) 5G NSA Sub-6: 3.4Gbps (DL)/550Mbps (UL) 5G NSA mmWave： 4.0Gbps (DL)/1.4Gbps (UL) LTE-FDD: 1.6Gbps (DL)/200Mbps (UL) WCDMA: 42Mbps (DL)/5.76Mbps(UL)	5G SA Sub-6: 7.01 Gbps (DL)/1.25 Gbps (UL) 5G NSA Sub-6: 5.47 Gbps (DL)/730 Mbps (UL) 5G NSA mmWave: 10.94 Gbps (DL)/4.16 Gbps (UL) LTE: 2 Gbps (DL)/ 211 Mbps (UL) WCDMA: 42 Mbps (DL)/ 5.76 Mbps (UL)
Temperature	-30℃ ~ +75℃

Model	FM160-EAU	FM650-CN
Band	5G Sub-6: n1/3/5/7/8/20/28/38/40/41/75/76/77/78 LTE FDD: B1/3/5/7/8/20/28/32 LTE TDD: B38/40/41/42/43 WCDMA: B1/5/8 5G NR: DL 44MIMO: n1/3/5/7/20/28/ 38/40/41/75/76/77/78 □□□□□□UL 22MIMO: n41/77/78 LTE: DL 4*4MIMO: B1/3/5/7/20/28/32/38/40/ 41/42/43	5G Sub-6: n1/28/41/78/79 LTE FDD: B1/2/3/5/7/8 LTE TDD: B34/38/39/40/41 WCDMA: B1/2/5/8 5G NR: DL 44MIMO: n1/41/78/79 □□□□□□DL 22MIMO: n28 □□□□□□UL 22MIMO: n41/78/79 □□□□□□UL 11MIMO: n1/28 LTE: DL 22 MIMO: B1/2/3/5/7/8/34/38/39/40/41 □□□UL 11 MIMO: B1/2/3/5/7/8/34/38/39/40/41
Data	NR SA: 2.5Gbps (DL)/900Mbps (UL) NR NSA: 3.5Gbps (DL)/555Mbps (UL) LTE: 1.6Gbps (DL)/211Mbps (UL) WCDMA: 42Mbps (DL)/5.76Mbps (UL)	NR SA:1.92Gbps (DL)/600Mbps (UL) NR ENDC: 1.92Gbps (NR DL)/380Mbps (NR UL) LTE: 487Mbps (DL)/150Mbps (UL) WCDMA: 42Mbps (DL)/11Mbps (UL)
Temperature	-30℃ ~ +75℃

III. Work with Raspberry Pi OS

Different versions of Raspberry Pi OS have varying strategies for network management. Based on the 64-bit OS version, we conducted tests after configuring 5G modules, and the results are as follows:

Model	OS version	Test results
RM500U-CNV/EA	2023-05-03-bullseye	Driver-Free, No Dial-Up Required, Auto-identification, plug and play, automatic internet connection.
RM520N/530N-GL/CN
RM551E-GLES
FM160-EAU
FM650-CN
RM500U-CNV/EA	2023-12-05-bookworm	Driver-Free, No Dial-Up Required, Auto-identification, but there may be instances of network connection failure, and the OS requires the installation of DNS software.
RM520N/530N-GL/CN
RM551E-GLES		Driver-Free, No Dial-Up Required, Auto-identification, plug and play, automatic internet connection.
FM160-EAU		Driver-Free, No Dial-Up Required, Auto-identification, but there may be instances of network connection failure, and the OS requires the installation of DNS software.
FM650-CN		Driver-Free, No Dial-Up Required, Auto-identification, plug and play, automatic internet connection.
RM500U-CNV/EA	2024-11-19-bookworm	Driver-Free, No Dial-Up Required, Auto-identification, but there may be instances of network connection failure, and the OS requires the installation of DNS software.
RM520N/530N-GL/CN
RM551E-GLES		Driver-Free, No Dial-Up Required, Auto-identification, plug and play, automatic internet connection.
FM160-EAU		Driver-Free, No Dial-Up Required, Auto-identification, but there may be instances of network connection failure, and the OS requires the installation of DNS software.
FM650-CN
RM500U-CNV/EA	2025-05-13-bookworm	Driver-Free, No Dial-Up Required, Auto-identification, but there may be instances of network connection failure, and the OS requires the installation of DNS software.
RM520N/530N-GL/CN
RM551E-GLES
FM160-EAU
FM650-CN

3.1 Test 5G module

The version of Raspberry Pi OS is: 2024-11-19-raspios-bookworm-arm64.img.xz.

You can download it in:

https://www.raspberrypi.com/software/operating-systems/#raspberry-pi-os-64-bit

The hardware platform is the CM4_5G_Mini paired with a Raspberry Pi 4B. We have already configured the 5G module to be driver-free and dial-up free under the Raspberry Pi OS, with auto-identification. (If the user uses their own 5G module, they need to configure it or develop drivers themselves; otherwise, plug-and-play cannot be achieved, and this section cannot be referenced.)

After powering on the OS, executing the command ifconfig -a in the terminal will show the 5G device:

The 5G module is set as usb0 and has obtained an IP address. We tested pinging external IP addresses and domain names, such as:

ping 220.189.255.38

ping www.mcuzone.com

It shows that only IP addresses can be pinged, while pinging domain names returns a DNS error:

At this point, it is necessary to install the DNS switching software udhcpc. The procedure is as follows:

Connect the Ethernet port of the Raspberry Pi 4B to the upstream router, then execute in the terminal:

sudo apt install udhcpc

After installation is complete, unplug the network cable and execute:

sudo udhcpc -i usb0

After execution, pinging both the IP address and the domain name was successful, indicating that the 5G module is functioning properly:

If the 5G module does not automatically obtain an IP address after OS startup, executing the udhcpc command can also enable it to acquire an IP address.

▶ View and switch internet connection priorities:

If there are multiple network connections in the OS that can access the internet simultaneously, you can use the route command to check the internet access priority, that is, which connection the OS uses to go online by default:

Currently, usb0 is ranked first, meaning the OS defaults to accessing the internet through the 5G module.

If you want to set the wired network (eth0) as the default internet connection, you can execute:

sudo udhcpc -i eth0

After the execution is complete, execute route again. You can see that eth0 now ranks first, meaning the OS defaults to accessing the internet through the wired network:

3.2 Confirm the USB3.0 port

For the CM4_5G_Mini USB3.0 driver board, connecting the USB cable in either the standard or reversed orientation can cause the USB port to operate in either USB3.0 or USB2.0 mode. To determine the orientation of the USB cable and confirm which mode it is operating in, you can execute lsusb -t to check.

▶ Running under USB3.0:

Execute lsusb and lsusb -t in the terminal, and the output is as follows:

The red box indicates the 5G module. If lsusb -t shows it operating at 5000M, then the USB cable is inserted in standard and it is running on USB3.0.

▶ Running under USB2.0：

Execute lsusb and lsusb -t in the terminal, and the output is as follows:

The red box indicates the 5G module. If lsusb -t shows it operating at 480M, then the USB cable is inserted in reverse and it is running on USB2.0.

IV. Work with Ubuntu OS

The version of Ubuntu OS is: ubuntu-25.04-preinstalled-desktop-arm64+raspi.img.xz.

You can download it in:

https://ubuntu.com/download/raspberry-pi

The hardware platform is the CM4_5G_Mini paired with a Raspberry Pi 4B. We have already configured the 5G module to be driver-free and dial-up free under the Ubuntu OS, with auto-identification. (If the user uses their own 5G module, they need to configure it or develop drivers themselves; otherwise, plug-and-play cannot be achieved, and this section cannot be referenced.)

The Ubuntu OS does not have the ifconfig tool by default. After the OS starts, first connect the Raspberry Pi 4B's network port to the upstream router, then manually install it in the terminal:

sudo apt install net-tools

After installation, unplug the network cable, then execute ifconfig -a in the terminal to see the 5G device:

The 5G module is a device starting with "enx" and has obtained an IP address. We tested pinging external IP addresses and domain names, such as:

ping 220.189.255.38

ping www.mcuzone.com

It shows that only IP addresses can be pinged, while pinging domain names returns a DNS error:

At this point, it is necessary to install the DNS switching software udhcpc. The procedure is as follows:

Connect the Ethernet port of the Raspberry Pi 4B to the upstream router, then execute in the terminal:

sudo apt install udhcpc

After installation is complete, unplug the network cable and execute:

sudo udhcpc -i enx1a9e7dd8b5e3

After execution, pinging both the IP address and the domain name was successful, indicating that the 5G module is functioning properly:

V. AT Commands for 5G

The usage of AT commands is the same on Raspberry Pi OS and Ubuntu OS. Here, we take Raspberry Pi OS as an example:

5.1 AT command operations

Take the RM520N-GL as an example, execute the command lsusb in the terminal, as shown in the figure below:

Record the ID value of the 5G module: 2c7c 0801.

Use the following command to open the ttyUSB serial port, where the value after echo is the ID recorded above:

sudo modprobe option

sudo sh -c 'echo 2c7c 0801 > /sys/bus/usb-serial/drivers/option1/new_id'

After execution is complete, the OS should have four additional devices: ttyUSB0-3. Input ls /dev/tty* to view:

If there are errors in the execution of the first two commands, these devices cannot be correctly generated, and the two commands must be re-executed properly.

Install minicom:

sudo apt-get install minicom

Open AT Command serial port by minicom:

sudo minicom -D /dev/ttyUSB2

(Note: Typically, four ports (ttyUSB0-3）will appear. In general, the AT port is ttyUSB2 under most OSs. If that doesn't work, you may try other ports such as ttyUSB0. If multiple USB-to-serial devices are present, further attempts will be needed until the correct AT port is identified.)

The first time you enter an AT command, there may be no echo. If you then input the command at and press Enter, and it returns "OK," it indicates that everything is working properly. If you need to check the echo, please type the command: ate1, then press Enter. After that, you can continue to type other commands and see the inputs.

5.2 Common AT commands

1. Check if the SIM card is detected:

at+cpin?

Return ready to indicate the card has been recognized, if return error, you need to check the hardware.

2. Check antenna signal quality:

Different models of 5G modules may use different AT commands to check antenna signal quality. The main test commands are as follows:

at+QRSRQ

Applicable to RM520N, RM530N, RM551E, etc.

Example return values are as follows:

+QRSRQ:-12,-16,-32768,-32768, NR5G

The first number indicates the RSRQ value of the PRX path. Range: -20 to -3 dB.

The second number indicates the RSRQ value of the DRX path. Range: -20 to -3 dB.

Just look at the first two numbers.

RSRQ	Coverage strength level	Notes
RSRQ > -10dB	1	The signal strength is excellent, suitable for high-speed data transmission and high-quality voice calls.
-10dB ≤ RSRQ ≤ -15dB	2	The signal strength is good, suitable for most data transmissions and voice calls.
-15dB ≤ RSRQ ≤ -20dB	3	The signal strength is fair, suitable for low-speed data transmission and low-quality voice calls.
RSRQ < -20dB	4	The signal strength is very poor, which may result in slower data transmission speeds or connection drops.

In the example above, the RSRQ values are -12dB and -16dB respectively, indicating that the signal quality ranges from good to average.

at+CESQ

Applicable to RM500U, FM160, FM650, etc.

Example return values are as follows:

+CESQ: 99,99,255,255,255,255,74,59,68

The last digit can calculate the RSRP value, which indicates the signal strength. The method is as follows:

Subtract 140 from this value to obtain the RSRP value. For example, in this case, RSRP=68-140=-72dBm, and then refer to the table:

RSRP(dBm)	Coverage Intensity Level	Notes
RSRP<=-105	6	Poor coverage. The service can hardly make calls.
-105<RSRP<=-95	5	Coverage is weak. Voice calls can be made outdoors, but the success rate is low with a high drop call rate. Indoor calls are nearly impossible to establish.
-95<RSRP<=-85	4	Coverage is average. various services can be initiated outdoors, providing low-rate data services. However, indoor call success rates are low, and the drop call rate is high.
-85<RSRP<=-75	3	Coverage is good. Outdoor areas support various services with medium-rate data, while indoor areas support services but only at low data rates.
-75<RSRP<=-65	2	With good coverage, high-speed data services can be initiated outdoors for various applications. Indoors, various services can be initiated with medium-rate data services.
RSRP>-65	1	The coverage is very good.

RSRP=-72dBm corresponds to coverage level 2, which indicates good coverage strength, meaning the signal strength is good.

3. Check network registration status:

at+cops?

Normally, it should return the network supporter's code: 7 or 11, where 7 represents 4G, and 11 represents 5G.

Note: Among the above three commands, only the one for checking antenna signal quality (at+QRSRQ/at+CESQ) should be used without a question mark, while the other two commands require a question mark.

4. View the SIM card's IMEI code:

at+cgsn

5. Reset 5G module:

Sometimes, if you reinsert the SIM card, hot swapping may not work; in such cases, you can use this reset command to reset the module.

at+reset

6. Enable/disable radio frequency:

Disable radio frequency:

at+cfun=0

Enable radio frequency:

at+cfun=1

The two commands mentioned above can be used in pairs to allow the module to re-register with the network without restarting the 5G module.

VI. Work with OpenWrt

The OpenWrt is compiled by our company, and the version is: openwrt-bcm27xx-bcm2711-rpi-4-squashfs-sysupgrade-lean-linux-6.12.43-qmodem-20250828.img.gz

The CM4_5G_Mini driver board + Raspberry Pi 4B can be configured with: the Raspberry Pi 4B's Gigabit Ethernet as LAN, and the 5G module as WAN.

6.1 Preparation

Connect the Raspberry Pi 4B's Gigabit Ethernet to the PC, go to Windows Settings, find Network & Internet, and open the connected network under Ethernet to view the default gateway IP address. This address is the access address for the OpenWrt's configuration page. As shown in the figure, the tested address in this article is 192.168.198.1.

Then open a web browser, enter 192.168.198.1 to access the OpenWrt. The default username is root, and the default password is password:

6.2 Check network

Click on "Services - Terminal," then log in to the terminal. The default username is root, and the password is password:

Execute ifconfig -a, and the result is as follows:

At this point, the 5G module (usb1) has obtained an IP address, that is, the OS has set usb1 as WAN.

Click "Network - Interfaces", you can also see that a default 5G network connection is already executing:

We pinged both the IP and the domain, and both were successful, indicating that the 5G module is functioning properly:

At this point, the properties of the PC network card connected to the Gigabit Ethernet (LAN port) of the Raspberry Pi 4B show internet connectivity:

Therefore, the PC can access the internet.

6.3 Configure 5G module as WAN

If the customer is using another OpenWrt, and the OS has not configured the 5G module as the WAN, it can be configured through the following steps:

Click "Network - Interfaces" - "Add new interface...":

Configure as shown in the figure, where the "Name" can be customized, and then click the "Create Interface" button:

In the "Firewall Settings", set "Create / Assign firewall-zone" to "wan", then click "Save":

Save and return to the previous page, then click "Save & Apply":

Wait a moment, and you will see the extended the 5G obtain an IP address:

Thus, we have completed the WAN configuration.

6.4 AT command operations

In the OpenWrt, using AT commands with a 5G module can be done through the minicom serial port tool. First, you need to install minicom in the OS. The steps are as follows (ensure that the OS's WAN port can connect to the Internet):

Click "System - Software", then click the "Update lists..." button:

Close the prompt window after the update is complete:

In the box under "Download and install package", enter "minicom" and then click "OK":

Click "Install":

After installation, click "Dismiss":

Then log into the terminal and configure the serial port in the terminal. Take the RM520N-GL as an example, execute the command lsusb in the terminal, as shown in the figure below:

Record the ID value of the 5G module: 2c7c 0801.

Use the following command to open the ttyUSB serial port, where the value after echo is the ID recorded above:

modprobe option

sh -c 'echo 2c7c 0801 > /sys/bus/usb-serial/drivers/option1/new_id'

After execution is complete, the OS should have four additional devices: ttyUSB0-3. Input ls /dev/tty* to view:

If there are errors in the execution of the first two commands, these devices cannot be correctly generated, and the two commands must be re-executed properly.

By default, the AT command serial port of RM520N-GL is ttyUSB2.

Open AT Command serial port by minicom:

minicom -D /dev/ttyUSB2

(Note: Typically, four ports (ttyUSB0-3）will appear. In general, the AT port is ttyUSB2 under most OSs. If that doesn't work, you may try other ports such as ttyUSB0. If multiple USB-to-serial devices are present, further attempts will be needed until the correct AT port is identified.)

The first time you enter an AT command, there may be no echo. If you then input the command at and press Enter, and it returns "OK," it indicates that everything is working properly. If you need to check the echo, please type the command: ate1, then press Enter. After that, you can continue to type other commands and see the inputs.

For commonly used AT commands, please refer to:

5.2 Common AT commands

Contact Us

QQ：8204136

Email: mcuzone@vip.qq.com

Tel: +86(0)13957118045

If there are any omissions, errors, or infringements on this page, please contact us through the above methods. Thank you!