add source code link on M5camera

docs/en/core/m5stickc.md

@@ -30,6 +30,15 @@ M5stickC is one of the core devices in M5Stack product series which is built in
 * If you find out your M5StickC couldn't power on without a USB in, it might because the battery enter the battery protection mode, caused by low-volatge, over-charged, ver-heat ... To exit the battery protection mode, please keep charging the battery for around 40 mins. Our team is working on the solution.
 
 <img src="assets/img/product_pics/core/minicore/m5stickc/m5stickc_02.png" alt="gray_02" width=50% height=50%><img src="assets/img/product_pics/core/minicore/m5stickc/m5stickc_08.png" alt="gray_02" width=50% height=50%>
+<br><br><br>
+
+*Notice*: One issue commonly exists on M5Stick-C, which happens when the battery is at a low level. In this case, some of the devices will have problem powering on, this is probably caused by a chaos timing sequence of power-on of ESP32, some component is involved, such as AXP192, 552, ESP32.  There is one way to bring the device back to live: 
+- 1, Connect G0 to 3V3.        
+- 2. Plug in the USB cable. 
+- 3, The screen will light up and leave the USB to charge the device. 
+
+
+<img src="assets/img/product_pics/core/minicore/m5stickc/m5stickc_05.jpg" width=50% height=50%>
 
 ## Product Features
 

docs/en/unit/m5camera.md

@@ -212,7 +212,9 @@ The hardware also comes with some reserved weld pad, just in case you want put t
  - **[QRcode](https://github.com/m5stack/m5stack-cam-psram/tree/master/qr/firmware/Camera%20B)**
 
  - **[MPU6050](https://github.com/m5stack/m5stack-cam-psram/tree/master/mpu6050/firmware/Camera%20B)**（Gyro Example after soldering **MPU6050**）
-
+ 
+### Source Code
+ - **[M5Camera](https://github.com/m5stack/m5stack-cam-psram)**
 
 ## Schematic
 

docs/en/unit/m5camera_f.md

@@ -195,6 +195,9 @@ The hardware also comes with some reserved weld pad, just in case you want put t
 
  - **[MPU6050](https://github.com/m5stack/m5stack-cam-psram/tree/master/mpu6050/firmware/Camera%20F)**（Gyro Example after soldering **MPU6050**）
 
+### Source Code
+ - **[M5Camera](https://github.com/m5stack/m5stack-cam-psram)**
+
 ## Schematic
 
 ### Power circuit

docs/en/unit/m5camera_x.md

@@ -191,7 +191,9 @@ The hardware also comes with some reserved weld pad, just in case you want put t
 
  - **[MPU6050](https://github.com/m5stack/m5stack-cam-psram/tree/master/mpu6050/firmware/Camera%20X)**（Gyro Example after soldering **MPU6050**）
 
-
+### Source Code
+ - **[M5Camera](https://github.com/m5stack/m5stack-cam-psram)**
+ 
 ## Schematic
 
 ### Power circuit