During the on-screen Display (OSD) test, output signals from the OSD node may disappear because the pen is short-connected instantly. When the ArduCAM OSD Config software is used to connect to the OSD node, a dialog box is displayed indicating “Failed to talk to bootloader”. There are few Chinese search results for this problem, but I found a solution in the video of Model airplane God Bubbles, and I will refine this method and write down my own detours.

Environment and Tools

OSD:3DRMinimOSD

The configuration software is ArduCAM OSD Config 2.1.3.0

Writing software: Arduino 1.8.13

Driver software: Zadig v2.4.721

FTDI USB to TTL board X1

USB ASP download /USB ISP download line X1 Note: buy the following one

CH341A USB to UART IIC SPI TTL ISP EPP/MEM Parallel port converter

The reasons for this will be mentioned later.

The solution

1. Connect the OSD node to the USB ASP download device

Connect the 10Pin interface of the downloader to the 6Pin interface marked ISP on the OSD using duPont cable or other means. Pins are defined as follows:

On OSD, square pin 1 (MISO) below J1 connects to pin 9 of downloader, VCC connects to pin 2 of downloader, GND connects to pin 10 of downloader, and SCK, RST, and MOSI connect to each other.

Here’s why I bought the wrong adapter. This is because there is no pin defined as RST in the USB-to-SPI board, which will cause subsequent write failures.

2. Burn write Bootloader

When the downloader connects to the computer, a USBasp device with an exclamation mark appears in the Device Manager. Since I am running Windows 10, I need to install the driver using Zadig. Windows 7 and below should only need to search and install the USBasp driver.

(Click “Install” after inserting)

Open Arduino, click the tool, select the development board, processor and programmer as shown in the figure below, select the port COM number, and click to burn the boot program.

After the burning is complete, the message “Warning: Cannot set SCK period” is displayed. Ignore it.

3. Reconnect the parameter adjustment software

Connect the FTDI board to the OSD and insert the FTDI board into the PC. Here:

  • Mark interconnections of GRNS (or GRNS connected to DTR)
  • + 5 v interconnect
  • RX and TX are connected
  • TX and RX are connected
  • GND, CTS, and BLK are interconnected

Open ArduCAM OSD Config, select COM port, click “Read From OSD”, if The previous steps are successful, here directly popup “The EEPROM mapping is outdated” After a period of time, the Done Writing Configuration Data message is displayed and the blue indicator on the OSD is blinking.

Options: Update Firmware: hex: Update Charset: MCM: Update Firmware: hex: Update Charset: MCM I wish you all success in saving brick!