SIM7600G-H 4G 模组使用指南

System: Radxa Rock 5T · Ubuntu 24.04 · Kernel 6.1.115-3-rockchip
模组: SimCom SIM7600G-H 安装在 M.2 B-Key插槽
目标: 每次开机自动建立 LTE 连接

确认 GPIO 引脚

SIM7600G-H 通过 RK3588 的 4 个 GPIO 引脚进行控制。
Linux GPIO编号的计算公式为: Bank × 32 + Group × 8 + Bit

Signal	GPIO Name	Calculation	Linux No.	电平逻辑
`4G_PWREN`	GPIO2_B1	2×32 + 1×8 + 1	73	高电平有效
`4G_WAKE_ON_HOST`	GPIO2_B2	2×32 + 1×8 + 2	74	高电平有效
`4G_RESET#`	GPIO2_B3	2×32 + 1×8 + 3	75	低电平有效
`4G_DISABLE#`	GPIO3_A6	3×32 + 0×8 + 6	102	低电平有效

警告

RESET# 与 W_DISABLE#均为低电平有效信号。低电平分别代表正在复位或射频已关闭。把这两个引脚拉低会导致模组无法启动。

导出 GPIO 并启动模组（手动测试）

# Export GPIOs and set as output
for pin in 73 74 75 102; do
    echo $pin | sudo tee /sys/class/gpio/export
    echo out | sudo tee /sys/class/gpio/gpio${pin}/direction
done

# Set clean initial state
echo 0 | sudo tee /sys/class/gpio/gpio73/value   # Power OFF
echo 1 | sudo tee /sys/class/gpio/gpio75/value   # RESET# HIGH (inactive)
echo 1 | sudo tee /sys/class/gpio/gpio102/value  # W_DISABLE# HIGH (RF enabled)
sleep 1

# Power on
echo 1 | sudo tee /sys/class/gpio/gpio73/value
sleep 2

# Send reset pulse
echo 0 | sudo tee /sys/class/gpio/gpio75/value
sleep 0.5
echo 1 | sudo tee /sys/class/gpio/gpio75/value
sleep 15

# Modem should now appear
lsusb | grep -i sim
# Expected: ID 1e0e:9001 SimTech, Incorporated

验证模组

mmcli -L
mmcli -m 0

预期输出应包含:

model: SIMCOM_SIM7600G-H
state: locked（需要输入 SIM PIN）
ports: cdc-wdm0 (qmi), ttyUSB0..4, wwan0 (net)

解锁 SIM PIN 并关闭 PIN 校验

# Install minicom
sudo apt install minicom -y

# Connect to AT command port
sudo minicom -D /dev/ttyUSB2 -b 115200

在 minicom 中执行以下 AT 命令:

AT+CPIN?           # → +CPIN: SIM PIN  (PIN required)
AT+CPIN="1234"     # Enter your PIN
AT+CPIN?           # → +CPIN: READY

# Disable PIN lock permanently (recommended for embedded use)
AT+CLCK="SC",0,"1234"

# Check network
AT+CSQ             # Signal strength (>10 = good)
AT+CREG?           # → 0,1 = registered
AT+COPS?           # Show network operator

解决 APN 问题（Telekom 运营商配置）

模组出厂默认携带 carrier config: Commercial-DT。Deutsche Telekom 网络强制要求使用 INTERNET.TELEKOM 作为唯一允许的 APN。依托 Telekom 网络的虚拟运营商（例如 Congstar、Aldi Talk）也必须使用该 APN。

# Install libqmi
sudo apt install libqmi-utils -y

# Set interface to raw_ip mode
sudo ip link set wwan0 down
echo 'Y' | sudo tee /sys/class/net/wwan0/qmi/raw_ip
sudo ip link set wwan0 up

# Create qmi-network configuration
sudo nano /etc/qmi-network.conf

APN=INTERNET.TELEKOM
PROFILE=2

# Test connection
sudo qmi-network /dev/cdc-wdm0 start
# → "Network started successfully"

# Read IP from QMI
sudo qmicli -d /dev/cdc-wdm0 --wds-get-current-settings

开机自动连接脚本

创建连接脚本:

sudo nano /usr/local/bin/sim7600-connect.sh

#!/bin/bash

# GPIO Init — Power on modem
for pin in 73 74 75 102; do
    echo $pin > /sys/class/gpio/export 2>/dev/null
    echo out > /sys/class/gpio/gpio${pin}/direction
done
echo 0 > /sys/class/gpio/gpio73/value   # Power off
echo 1 > /sys/class/gpio/gpio75/value   # RESET# inactive
echo 1 > /sys/class/gpio/gpio102/value  # RF enabled
sleep 1
echo 1 > /sys/class/gpio/gpio73/value   # Power on
sleep 2
echo 0 > /sys/class/gpio/gpio75/value   # Reset pulse
sleep 0.5
echo 1 > /sys/class/gpio/gpio75/value

# Wait for USB modem to appear (max 30s)
echo "Waiting for modem..."
for i in $(seq 1 30); do
    [ -c /dev/cdc-wdm0 ] && break
    sleep 1
done

# Clean up old QMI state (prevents "PDH already exists" error)
rm -f /tmp/qmi-network-state-cdc-wdm0

# Prepare interface
ip link set wwan0 down
echo 'Y' > /sys/class/net/wwan0/qmi/raw_ip
ip link set wwan0 up

# Bring up connection
qmi-network /dev/cdc-wdm0 stop 2>/dev/null
sleep 1
qmi-network /dev/cdc-wdm0 start
sleep 3

# Get IP address from QMI and configure interface
IP=$(qmicli -d /dev/cdc-wdm0 --wds-get-current-settings 2>&1 \
    | grep "IPv4 address" | awk '{print $NF}')
DNS1=$(qmicli -d /dev/cdc-wdm0 --wds-get-current-settings 2>&1 \
    | grep "IPv4 primary DNS" | awk '{print $NF}')
DNS2=$(qmicli -d /dev/cdc-wdm0 --wds-get-current-settings 2>&1 \
    | grep "IPv4 secondary DNS" | awk '{print $NF}')

if [ -n "$IP" ]; then
    ip addr flush dev wwan0
    ip addr add ${IP}/32 dev wwan0
    # No gateway needed for raw_ip point-to-point
    ip route add default dev wwan0 metric 700
    resolvectl dns wwan0 $DNS1 $DNS2 2>/dev/null
    echo "LTE active: $IP"
else
    echo "ERROR: Failed to get IP address!"
    exit 1
fi

sudo chmod +x /usr/local/bin/sim7600-connect.sh

创建 Systemd 服务

sudo nano /etc/systemd/system/sim7600-init.service

[Unit]
Description=SIM7600 Modem Init and Connect
After=sysinit.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/local/bin/sim7600-connect.sh

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable sim7600-init.service

# Disable ModemManager (conflicts with direct QMI usage)
sudo systemctl disable ModemManager

手动切换 LTE

创建一个在切换到 WiFi 时关闭 LTE 的脚本:

sudo nano /usr/local/bin/lte-off.sh

#!/bin/bash
qmi-network /dev/cdc-wdm0 stop
rm -f /tmp/qmi-network-state-cdc-wdm0
ip addr flush dev wwan0
ip link set wwan0 down
echo 0 > /sys/class/gpio/gpio73/value
echo "LTE off."

sudo chmod +x /usr/local/bin/lte-off.sh

# Usage:
sudo lte-off.sh              # Turn LTE off, use WiFi
sudo sim7600-connect.sh      # Turn LTE back on

测试连接

# After reboot or manual start:
ip addr show wwan0          # IPv4 address must be visible
ip route show               # default via wwan0 must be present
ping -c 3 8.8.8.8           # Ping over LTE
curl -s ifconfig.me         # Show public IP
nmcli radio wifi off        # Disable WiFi — LTE only
ping -c 3 google.com        # DNS test
nmcli radio wifi on         # Re-enable WiFi

排障

问题	原因	解决方案
`lsusb` 中看不到模组	RESET# 电平逻辑反了（低电平有效！）	正常工作时保持 gpio75 = HIGH
出现 `unknown-apn`错误	Telekom运营商配置阻止自定义 APN	使用 `APN=INTERNET.TELEKOM`
出现 `PDH already exists`错误	/tmp 中残留旧的状态文件	`rm -f /tmp/qmi-network-state-cdc-wdm0`
连接后没有 IPv4	raw_ip模式下 DHCP 不生效	通过 `qmicli --wds-get-current-settings`手动设置 IP
开机时服务失败	ModemManager 占用了 cdc-wdm0	通过 systemctl禁用 ModemManager

确认 GPIO 引脚​

导出 GPIO 并启动模组（手动测试）​

验证模组​

解锁 SIM PIN 并关闭 PIN 校验​

解决 APN 问题（Telekom 运营商配置）​

开机自动连接脚本​

创建 Systemd 服务​

手动切换 LTE​

测试连接​

排障​