调试米尔开发板记录

gpio调试：
ls /sys/class/gpio/
echo 2 > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio2/direction
cat /sys/class/gpio/gpio2/direction

echo "0" > /sys/class/gpio/gpio2/value
echo "1" > /sys/class/gpio/gpio2/value

echo 48 > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio48/direction
cat /sys/class/gpio/gpio48/value

echo 48 > /sys/class/gpio/export
echo 49 > /sys/class/gpio/export
echo 50 > /sys/class/gpio/export
echo 51 > /sys/class/gpio/export
echo 52 > /sys/class/gpio/export
echo 53 > /sys/class/gpio/export
echo 110 > /sys/class/gpio/export
echo 112 > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio49/direction
echo "in" > /sys/class/gpio/gpio48/direction
echo "in" > /sys/class/gpio/gpio50/direction
echo "in" > /sys/class/gpio/gpio51/direction
echo "in" > /sys/class/gpio/gpio52/direction
echo "in" > /sys/class/gpio/gpio53/direction
echo "in" > /sys/class/gpio/gpio110/direction
echo "in" > /sys/class/gpio/gpio112/direction
cat /sys/class/gpio/gpio49/value

网口：
ifconfig eth0 192.168.1.100 netmask 255.255.255.0
route add default gw 192.168.1.1

关wifi

make menuconfig
Networking support → Wireless 下打开cfg80211选项支持：
Device Drivers → Network device support → Wireless LAN下打开BCM 43XX SDIO 设备驱动支持：
选择下方的<Save>选项保存，重新清理编译，<Load>刚刚的保存方案，make Image保存即可

I. echo 0 > /sys/class/pwm/pwmchip3/export /*设置PWM4输出，调出pwm0目录下设备节点，用于以下配置 */

II. echo 1 >/sys/class/pwm/pwmchip3/pwm0/enable/*设置PWM4使能 */

III. echo 1000000 >/sys/class/pwm/pwmchip3/pwm0/period/*设置PWM4一个周期的持续时间，单位为ns，即1K Hz */

IV. echo 500000 >/sys/class/pwm/pwmchip3/pwm0/duty_cycle/*设置一个周期中的”ON”时间，单位为ns，即占空比=duty_cycle/period=50% */

485测试：
rs485_read -d /dev/ttymxc2 -b 115200 -e 1
rs485_write -d /dev/ttymxc2 -b 115200 -e 1

gpio:
echo 27 > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio27/direction
echo "1" > /sys/class/gpio/gpio27/value //rs4853发送

echo "0" > /sys/class/gpio/gpio27/value //rs4853接收

spi调试：
spi mode: 0
bits per word: 8
max speed: 500000 Hz (500 KHz)

spi mode: 1
bits per word: 8
max speed: 200000 Hz (200 KHz)
82
FF FF FF FF FF FF
rx:91 rx:C4 rx:00 rx:00 rx:FF rx:FF
rx:3D rx:7F data :15743

PWM调试：
echo 0 > /sys/class/pwm/pwmchip0/export
echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable
echo 10000 > /sys/class/pwm/pwmchip0/pwm0/period
echo 5000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle

echo 0 > /sys/class/pwm/pwmchip1/export
echo 1 > /sys/class/pwm/pwmchip1/pwm0/enable
echo 10000 > /sys/class/pwm/pwmchip1/pwm0/period
echo 5000 > /sys/class/pwm/pwmchip1/pwm0/duty_cycle