USB to RS232 Chipset CH340 Serial Converter 9 Pin Adapter

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stevesmythe

Senior Member
On Windows 10, you don't need to install anything manually with those cables. Go into control panel/device manager and you should see an extra COM port with the cable plugged in. If you have an older version of Windows, let us know and someone will come to your aid I am sure.
 
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coparu67

Senior Member
I work with Windows 7
Now I have (I think) an extra COM5 port
But, when I try PE6 > "Check PICAXE Type connected" I get "Error: hardware not found on COM5"
(All fine with a PICAXE USB Cable)

USB-SERIAL CH340 (COM5) ICON.PNGUSB-SERIAL CH340 (COM5).PNG
 
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SAborn

Senior Member
Do you realize the com port is only for the 1 usb socket you had the cable installed in when you installed the driver.
You did have the cable plugged in before you installed the driver?
Each usb port will normally require the driver to be installed and each usb port will then have a different com port number.

Bottom line is the driver only works to the usb port it is assigned to, not just any usb port.
 
hippy

hippy

Technical Support
Staff member
coparu67 said:
I work with Windows 7
Now I have (I think) an extra COM5 port
But, when I try PE6 > "Check PICAXE Type connected" I get "Error: hardware not found on COM5"
(All fine with a PICAXE USB Cable)
Click to expand...
Using the AXE027, download the following program which will ensure it will not need a hard reset -

Code: 
Do : Loop
Then try to download with the CH340. If that doesn't work then it's either a faulty cable, a cable using a chipset which doesn't support beak signalling, or you have the wrong drivers installed.

We recommend the AXE027 cable to avoid problems and the effort required to resolve issues. Trying to save money by buying cheap cables can be a false economy. They may be great if they work, a lot of frustration when they don't.
 
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AllyCat

Senior Member
Hi,

That USB adapter should work (if it has a genuine CH340 chip). If you unplug the adapter does the "COM5" disappear? If so, reconnect to ensure it is the correct port.

I believe the error message is saying that the PICaxe is not responding: Are you sure the programming connections are correct, and the PICaxe has a good power supply?

Is it a new PICaxe? If so, it should give a message in the PICaxe Editor Terminal window. If not, what program was loaded (a hard reset procedure may be necessary)?

Cheers, Alan.

PS: I would expect that adapter with the "real" chip in #6 above NOT to work. It is described as "TTL" which implies that the data is inverted relative to the PICaxe requirement.
 
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coparu67

Senior Member
I run (with a PICAXE-USB Cable)
Do : Loop
in my PICAXE-18M2 chip.

The serial converter doesn't work.
I tried hard resets without success too.
If I unplug the adapter, the COM5 dissapears.
(If I plug in another slot, COM6 appears; if I unplug, it dissapears again).

I used drivers from this web:
http://www.geekfactory.mx/sin-categoria/driver-ch340-para-arduino-chinos-o-genericos/


adapter1.jpgadapter2.jpg
I had follow too instructions from PE6 to check Serial cables.
I get messages with the clip, but in next step I always get 0V (sometimes 0,1V).

hippy, from four years ago, all cables I've purchased (for my students) are USB-PICAXE Cables,
but I still have got some old Serial Cables and I was wondering if I can recycle them.
 
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hippy

hippy

Technical Support
Staff member
It is possible to use older 9-way cables though there can be occasional issues with TOUCH and ADC with M2 and X2 chips when using RS232 serial voltages which can be difficult to identify when they occur. That's another reason we recommend the AXE027 over RS232 these days.
 
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AllyCat

Senior Member
Hi,

coparu67 said:
I run (with a PICAXE-USB Cable)
Do : Loop
in my PICAXE-18M2 chip.
Click to expand...
If you can download a program (with a different cable) then try downloading a program like a "new" PICaxe:
Code: 
do
  pause 1000
  sertxd("Hello I am your PICAXE",cr,lf)
loop
Then open the serial terminal at 4800 baud. That may help to determine if the driver or cable has a severe fault or something that might be easily fixed.

I have used several similar CH340 "blue" USB adapters very successfully, but mine all had the USB plug on a long braided cable.

Cheers, Alan.
 
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coparu67

Senior Member
I downloaded the program with the USB-PICAXE Cable

I tried the Serial Terminal with the USB-Serial adapter and it works fine !!!!
I receive then "Hello I am your PICAXE" message every second (with the adapter).

So, it seems serial communication is working, I think,
but I cannot check the PICAXE type and I cannot download programs with the adapter.


AllyCat said:
If you can download a program (with a different cable) then try downloading a program like a "new" PICaxe:
Code: 
do
  pause 1000
  sertxd("Hello I am your PICAXE",cr,lf)
loop
Then open the serial terminal at 4800 baud. That may help to determine if the driver or cable has a severe fault or something that might be easily fixed.
Click to expand...
 
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AllyCat

Senior Member
Hi,

coparu67 said:
So, it seems serial communication is working, I think,
but I cannot check the PICAXE type and I cannot download programs with the adapter.
Click to expand...
That indicates that communication is good from the PICaxe to the PC, but not from PC to PICaxe.

Two possibilities are (1) a hardware fault on the PC transmit line or (2) the USB driver doesn't support the "break signalling" required to "wake up" the PICaxe into programming mode.

I suggest that you try to check the cable, etc. with a multimeter if you have one, and see if you can find another software driver. Also perhaps other members will have some other ideas?

We could write a more complex program to check if the PICaxe is receiving normal characters (but not the break signal), but it is too late for tonight. ;)

Cheers, Alan.
 
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inglewoodpete

Senior Member
Data loopback test

The paper clip loopback test that Goeytex describes here (post #15) can confirm that the USB-to-serial cable works in both directions (send and receive). However, it may not generate the "Break" signal required to interrupt the PICAXE.
 
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AllyCat

Senior Member
Hi,

There is some merit in testing that the transmitted RS232 signal is getting completely through to (and being recognised by) the PICaxe chip. The voltage level from the USB adapter might be different, or there might be a "mechanical" problem. For example, I've recently been testing the 3.5 mm jack sockets (as used for PICaxe programming) because I would like to use a "4 pole" version, as fitted to some headphones, computers and mobile phones, etc. (L/R stereo audio, microphone and earth). Not all of the connector contacts are completely compatible !

Basically it's necessary to use a SERRXD command (and enter characters at the Editor Terminal) but this command "Disconnects" the Programming capability which then requires a "Hard Reset". I believe the OP knows how to do this, but it's still an inconvenience. Here's some untested code to try:

Code: 
do
main:
	pause 2000
	serrxd [5000,failed], b1	; get character with timeout
	reconnect
	sertxd(#b1," received",cr,lf)
loop
failed:
	reconnect
	sertxd("Nothing received",cr,lf)
	goto main
Enter a single number/character in the send window, but note that the program may return more than one digit (the ASCII code).

Cheers, Alan.
 
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coparu67

Senior Member
Program run in my PICAXE-18M2 /CHI035)

Both cables, USB-PICAXE and USB-Serial-Adapter work in the same way from the Serial Terminal.
There aren't differences from them.

If I don't send anything, I get the "Nothing received" message
When I send a character, most of times I get the ascii code; sometimes an *



AllyCat said:
Hi,

Code: 
do
main:
	pause 2000
	serrxd [5000,failed], b1	; get character with timeout
	reconnect
	sertxd(#b1," received",cr,lf)
loop
failed:
	reconnect
	sertxd("Nothing received",cr,lf)
	goto main
Enter a single number/character in the send window, but note that the program may return more than one digit (the ASCII code).

Cheers, Alan.
Click to expand...
 
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AllyCat

Senior Member
Hi,

So it looks very much that the required "Break Signal" is not supported. That might be due to the driver (windows software) or that the "CH340" hardware is "fake".

I have had complete success with this style of "blue" adapter (cheaper if shpped direcly from China/HK) even using windows 10, but of course the suppliers are always changing so there can be no certainty of success.

Cheers, Alan.
 
Technical

Technical

Technical Support
Staff member
The PE6 AXE027 download cable test wizard will actually work with any cable - and the voltage test will test the 'break signal'.

CaptureBreakTest.PNG
 
Pongo

Pongo

Senior Member
Thanks Technical, another nice PE6 feature :)

I have an old ATEN chipset adaptor. It dates back to the early days of USB and surprisingly has continued to work well all the way through today's 64 bit OS's which I see other adaptors, both name brands and the "blue" one linked above, still can't handle.
 
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inglewoodpete

Senior Member
Pongo said:
Thanks Technical, another nice PE6 feature :)

I have an old ATEN chipset adaptor. It dates back to the early days of USB and surprisingly has continued to work well all the way through today's 64 bit OS's which I see other adaptors, both name brands and the "blue" one linked above, still can't handle.
Click to expand...
The ATEN USB to Serial adapter chip is actually made by Prolific (==PL2302) but has a different Vendor ID burnt into the USB interface. Full discussion here.
 
erco

erco

Senior Member
Pongo said:
TI have an old ATEN chipset adaptor. It dates back to the early days of USB and surprisingly has continued to work well all the way through today's 64 bit OS's which I see other adaptors, both name brands and the "blue" one linked above, still can't handle.
Click to expand...
Really? Mine stopped working on Windows 8.
 
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