關於RTC PCF8523的除錯記錄

#參考文獻連結：

• PCF8523

• Connect the PCF8523 RTC module to BBGw according to the drawing；

• Connect GND on the breakoutboard to the P9_1(GND) pin on the BB

• Connect SDA on the breakoutboard to the P9_20（I2C2—SDA） pin of the BB
  

檢測是否有68

i2cdetect -y -r 2

 the i address ：0x68

• rtc_pcf8523

• Make a new folder rtc_pcf8523

mkdir /usr/share/rtc_pcf8523

• clock_init.sh

• Make a new sh scripts clock_init.sh

• The purpose is to update the RTC time every 15s.

vi /usr/share/rtc_pcf8523/clock_init.sh

將此程式碼放入clock_init.sh

#!/bin/bash

sleep 15

echo pcf8523 0x68 > /sys/class/i2c-adapter/i2c-2/new_device
 

hwclock -s -f /dev/rtc1

hwclock -w

• 設定開機啟動自動更新時間

vi /lib/systemd/system/rtc-pcf8523.service

將綠色部分程式碼放入rtc-pcf8523.service檔案中

####The following is the content of rtc-pcf8523.service####

[Unit]

Description=PCF8523 RTC Service

[Service]

Type=simple

WorkingDirectory=/usr/share/rtc_pcf8523

ExecStart=/bin/bash clock_init.sh
 

SyslogIdentifier=rtc_pcf8523

[Install]

WantedBy=multi-user.target

• enable the service at reboot，Nothing response is OK

systemctl enable rtc-pcf8523.service

• start the service now，Nothing response is OK

systemctl start rtc-pcf8523.service

• check status

service rtc-pcf8523 status

• Restart the BBG system to ensure that the above configuration file takes effect：

reboot

• After rebooting, you will see that the original 0x68 address becomes UU, indicating that the device has achieved the boot-up target in the driver.

i2cdetect -y -r 2



• Correct RTC time

• If the system time is correct, the following commands can help you write the system time into the RTC module；

• If the system time is incorrect, you need to update the system time correctly before running the following command；

hwclock -w -f /dev/rtc1

• a simple test method：

• Disconnect BBG network connection

• Turn off the BBG system for a few minutes

• Start the BBG system and run the date command.

date