Problem programming arduino pro mini with FTDI cable

I just received my latest orderr and are having a problem with programming the pro mini.

How I setup the test
Download the latest driver for FTDI and updated the driver.
Plugged in cable and checked device manager

This device is working properly

Driver provider FTDI
Driver date 28/09/2016
Driver version
data speed 9600
data bits 8
parity none
stop bits 1
flow control none

Next connect mini pro to cable (not connected to computer)

GND black to GND on pro mini
VCC red to VCC on pro mini
Tx White to RX on pro mini
Rx Green to Tx on pro mini

Plugged in cable to PC
Red led comes on
Yellow led next to pin 10 flashes twice
Open arduino ide
Check for correct port and board type
(com8 pro mini, at mega328 (5V 16M)

Next compile blink sketch and try to upload.
While it complies ok it hangs while uploading and finally times out.
Can you please help.

Hey @Greg15937, try the following:
Connect everything up and get ready to upload.
Hit the upload button, and once the status message changes from Compiling to Uploading press the reset button on the pro mini once.

The Arduino bootloader only looks for new programs being uploaded in the first couple seconds of a reset. This is why an arduino sketch takes a moment to begin working.

On the “vanilla” Arduino boards like the UNO, a reset signal is sent (hacked) by the FTDI chip pulsing its DTR line.
If you have a DTR pin available on your FTDI breakout you could connect that to automate the reset process.

Let us know how you travel!

hi Michael

I am using the FT232 USB to TTL Serial Cable
FIT0416 as recommended by core electronics to use with the pro mini so no DTR signal
Tried as you suggested but still the same results that is can not upload the blink program.

Also double checked the wiring - all good

Kind Regards

Hi Greg,

Have you taken a look at our Serial programming tutorial? It walks through some of our favourite products, but also how to connect it all up. You may need to install the FTDI drivers. I’ve linked and described how to do this in the tutorial.

I have had a read of what you suggest and have the following comment.

The pin definition from your product page is as follows
and on page “Programming with USB-Serial Converters” a diagram shows clearly that TX and Rx should be swapped over which is normal.

What I have found out that Tx of the FTDI cable has to connect to Tx of the Arduino Pro Mini

Once I did this I can now download the program.

I did not know about resetting the pro mini which was part of the solution.

Please comment on the wiring labels.

Kind Regards

Hi Greg,
Hmm, that’s definitely strange. it could be that the wires were mislabelled on your converter

Hi Sam

The wires are not labeled at all. As stated I got the info from your site. For the sake of others I would investigate.

Glad to see you got there in the end! Perhaps DFRobot have counter normal information on this product. For products such as this, normally, TX and RX are contextual to the product. Not what it’s connecting to.

This is a very popular product, although we’ll check out some stock and will update DFRobot’s description if needed.

All the best with your projects!

1 Like

I have read on the net that some FTDI adapters use TX-TX and RX-RX whereas others are cross overs…see: