Inside USB-serial converter BLH7840

h-elsner

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BLH7840 is a FT230X chip based USB <--> serial converter. It is used to connect the Blade 350QX to computer to update firmware and if firmware version 3 is flashed to connect it to GUI for diagnosis. The GUI can be downloaded here: https://www.horizonhobby.com/pdf/350_QX_PC_Interface.zip

If the FT230 driver was installed correctly BLH7840t will appear in the device manager als serial interface once it is connected to USB (no need to connect to Blade at this time).
Com3USB.png

Here is BLH7840 open:

USBtoSer01a.jpg
USBtoSer02a.jpg

Remark: Masse means ground.

br HE
 

impaulb

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BLH7840 is a FT230X chip based USB <--> serial converter. It is used to connect the Blade 350QX to computer to update firmware and if firmware version 3 is flashed to connect it to GUI for diagnosis. The GUI can be downloaded here: https://www.horizonhobby.com/pdf/350_QX_PC_Interface.zip

If the FT230 driver was installed correctly BLH7840t will appear in the device manager als serial interface once it is connected to USB (no need to connect to Blade at this time).
View attachment 37

Here is BLH7840 open:

View attachment 35
View attachment 36

Remark: Masse means ground.

br HE
I see the blh 7840 in my device configured with the proper driver but still cannot connect with my QX. It just goes around & round saying trying to connect. I do not know the port setting it requires as far s baud rate etc.
 

h-elsner

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What firmware do you have on your Blade 350QX?

If you see the USB-serial converter in device manager assigned to a COM port driver and all this stuff are OK.

GUI works only with newer firmware. I do no more remember exactly. I'm sure it works with QX3 firmware but maybe also with 2.0. I have to dig deep to find the correct answer.

As COM properties I have this by default and it works:
Serial._properties.png

br HE
 

impaulb

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What firmware do you have on your Blade 350QX?

If you see the USB-serial converter in device manager assigned to a COM port driver and all this stuff are OK.

GUI works only with newer firmware. I do no more remember exactly. I'm sure it works with QX3 firmware but maybe also with 2.0. I have to dig deep to find the correct answer.

As COM properties I have this by default and it works:
View attachment 142

br HE
I have the old firmware version but cannot update because the BLH 7840 does not connect.How to tell if you are connected if the GUI does not work?
 

impaulb

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I can not get new firmware because the BLH7840 will not connect for communication.
The device manager says device is working and driver is the proper one.I need to know exactly where to connect the cable to the QX
 

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