Bypass CH340 in Nano with FTDI breakout

Other Hardware 3rd Party Boards
1

Hello,
I've looked in several topics but didn't find a successful solution.
After latest Windows updates now only Linux supports the CH340 chip. I used to have a dozen of working Nano clones, but now they're useless. I bought A FTDI breakout and Mini pro and managed to get it working. Is there a way to program these Nanos using the FTDI breakout? I've tried uploading with releasing reset just when upload shows up, but the devices don't communicate.

connections:

GND -> GND
CTS ->not connected
5V -> 5V
TXD ->RX
RXD ->TX
DTR ->GND

2

What makes you say that Windows no longer works with the CH340? I'm still using them just fine.

3

Here is a schematic of a typical CH340 Nano clone: http://actrl.cz/blog/wp-content/uploads/nano_ch340_schematics-rev1.pdf. It may help.

But first you must verify the statement you made about missing Windows driver support for this device.

4

I used to have a dozen of working Nano clones, but now they're useless.

I also am OK using some older nanos with CH340's with Windows 10 which is updated everytime Microsoft decides to torment me which is quite often.

Perhaps you are seeing the Old Bootloader/Optiboot issue. The default selection for the nano was switched to Optiboot some time ago.

If you see this selection available try it.
Tools > Processor > ATmega328P (Old Bootloader)

If this option is not there then you should use the Board Manger to update what you have for AVR boards.

5

Maybe get a Programmer and re-bootload them all as Uno to overcome serial download speed differences.

6

First Mac OS stopped supporting unsigned drivers, you could disable that check up to some version, same happens in latest Win 10 updates. CH340 used to work well with the Chinese drivers, but recently I got a problem in device manager (yellow warning sign). The issue wasn't resolved with reinstalling and installing the latest version of drivers. This could be resolved by booting into safe mode with the security layer disabled (it's not an option that satisfies me). Basically newest security features prevent the CH340 from working.

They used to work well in IDE with the old bootloader option. The problem is on the usb-serial level.

I got a new FTDI breakout and plan to move on to mini pro (which programs well on my system).

I'd like to make use of my old boards, instead of throwing them out and replacing by minis.

7

I'll be interested to see what happens with the CH340 Windows driver. Maybe the OP has got an non-signed version.

My Windows version is 10 Pro version 1809. My CH340 driver is dated 08.08.2014. version 3.4.2014.8 Provider wch.ch and is signed by Microsoft Windows Hardware Compatibility Publisher. Everything seems to work with CH340 devices.

CH340 Driver.JPG

In the meantime I have successfully loaded a sketch onto a CH340 Nano clone ( https://robotdyn.com/nano-v3-atmega-328-usb-ttl-ch340g-micro-usb.html ) using an FTDI USBTTL device.

The connections I used are :

FTDI    NANO
----    ----     
GND     GND
CTS      -
5V      Vin
TXD     RX0
RXD     TX1
DTR     Reset (via a 100nF capacitor)

CH340 Driver.JPG

8

My CH340 driver is dated 08.08.2014. version 3.4.2014.8 Provider wch.ch and is signed by Microsoft Windows Hardware Compatibility Publisher. Everything seems to work with CH340 devices.

That is the driver version which is working successfully for me with

Windows 10 Home
V1903
Updated 7/8/2019
OS 18362.295

9

Well, I got the driver from:

These are some older screenshots, can't find my only mini-usb cable (another reason to move from nanos)

Win ver. 1903

I'll try with the breakout again, but have only 10nF capacitors at hand.

mmc_HVi2R4jpLW.png
mmc_HVi2R4jpLW.png1171×858 139 KB

mmc_vH0HdVtHyY.png
mmc_vH0HdVtHyY.png611×682 46.7 KB

10

Okay,
I've found a 100uF Capacitor (16v)

tried this scheme:

FTDI    NANO
----    ----    
GND     GND
CTS      -
5V      Vin
TXD     RX0
RXD     TX1
DTR     Reset (via a 100nF capacitor)

I tried reversing TX and RX, tried reversing the capacitor. Doesn't work. Set Nano with old bootloader (as worked over mini-usb) Mini pro works well with the same breakout. :confused:

11

BREAKTHROUGH

guys, I don't know what happened, but the Nanos now started working??

I've found the mini-usb cable, and wanted to take a screenshot of that driver problem. Now they show up correctly in the device manager and I've successfully uploaded sketches.

mmc_imUCWTB13k.png
mmc_imUCWTB13k.png611×682 70.6 KB