Follow this operation manual. 

Update the firmware as follows:
1. Put the STM32F4_UPDATE folder into the SD card
2. Reboot the machine and wait for the update to complete.

Screen update：
Put the private and TJC_SET folders under the screen firmware file into the tf card -> insert the tf card into the tf interface of the screen -> connect the screen cable -> restart the machine and wait for the screen update to finish

BootLoader update for Stm32f401：
Use burn tool to burn STM32f401RCTx_BootLoader_v1.bin Start address 0x8000000

Note: In this update, it needs to update the mainboard firmware and screen firmware.   Mainboard Update & Instructions:  1. Move the "Ender-3 S1 hw24s1_301-sw-V1.0.6_C-CRTouch_F103_FDM+LASER.bin" file to the SD card.  2. Restart the 3D printer.  3. Wait until the update is finished.  Screen Update & Instructions:  1. Move a folder named "private" to the TF card.  2. Insert the TF card into the screen card slot.  3. Connect the screen cable.  4. Restart the 3D printer and wait until the update is finished.

Note: In this update, it needs to update the mainboard firmware, screen firmware and BootLoader.  Firmware Update:  1. Create a new folder named "STM32F4_UPDATE" under the root directory on the SD card.  2. Mainboard Update & Instructions:  1) Move the "Ender-3s1_hw24s1_301_V3.0.3_F401_20220104.bin" file to "STM32F4_UPDATE" folder.  2) Insert the SD card into the printer card slot.  3) Restart the 3D printer and wait until the update is finished.  Screen Update & Instruction:  1. Move a folder named "private" to the TF card.  2. Insert the TF card into the screen card slot.  3. Connect the screen cable.  4. Restart the 3D printer and wait until the update is finished.BootLoader Update for Stm32f401:1. Use the flash tool to flash the "STM32f401RCTx_BootLoader_v1.bin" file

Ender-3 S1_HW-V24S1_301_SW-V1.0.5_C-CRTouch