Pro Mini Programming Problems


I have a couple Pro Mini Arduinos and an FTDI Basic Programmer.

I pick the Board and the Processor, not sure which programmer to pick in Arduino IDE.

I have tried them all. My Basic has 3.3 or 5V. My Pro Mini is suppose to be 5V 16 MHz.

It will not program. I get several messages and lots of stuff with it tries to program.

It says it has synchronization error. It grinds away. I have tried all combinations.

I loaded the driver down from FTDI. It seems to be OK. Installs as COM14.

I am not sure what baud rate to set in Windows. I have tried 56 KB as well as others.

I am using W7 and latest Arduino and can program my Nanos just fine.

Any experience.

Here are some of the errors??????????

Using Port : COM14

Using Programmer : arduino

Overriding Baud Rate : 57600

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xff

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00

You don't need to pick a programmer in the IDE, because FTDI basic is not a programmer, it is just a USB to serial interface. There are numerous things which could cause these problems, so best to do some basic troubleshooting.

First, at the top of the Installation and Troubleshooting forum there are some pinned posts, and one is called Loop Back Test. Do that test on your FTDI basic. This amounts to disconnecting it from the Pro Mini, and connect a wire between the RX and TX pins. Open the IDE serial monitor and enter some text in the Send field and click Send. You should see the text you type appear in the window below. That means the FTDI basic is working ok. If this does not work, you probably don't have the right port selected, or drivers not installed for the FTDI basic.

If the loop back test does work, please upload a photo which shows how you are connecting the FTDI basic to the Pro Mini. And let us know if you get any LEDs glowing or flashing on the Pro Mini when it is hooked up and you're trying to upload to it. Try the 3.3V 8MHz selection in the Tool, Processor menu, just in case you were sent a 3.3V Pro Mini by mistake.

Thanks Mucho!

I connected Tx and Rx together on the Serial Breakout, no Arduino.

I plugged it into the USB, went to Device manager and saw it as COM14.

I connected to RealTerm and set it to COM14. I type in a letter and it IS sent to the monitor.

I am wondering. Could I have Pro Mini without Boot loader?

The lights all flash like it is trying to program, but give the sync errors.

Thanks Again! I will go back to try again, maybe I should hold reset button too. I am going to try another Mini too, I bought several.


So, I got the voltmeter out and did some De-bug.

I put the Serial Connector on the Pro-Mini with the Right Angle Pins UP.

Wrong. I flipped the Mini over and fine so far even at 3.3V and 8Mhz.

Thanks, I will solder the connect the other way on the next one, seems
like you would want the Leds and Reset switch UP?

Thanks, Again.

You got me going this morning!

I can't really tell what you are talking about without seeing pictures.

It could be possible that the Pro Mini don't have a bootloader, may you bought it in china.

Could you give us some pictures from the wiring to USB-TTL? And did you connect USB TTL TX to RX (PRO mini) And the USB TTL RX to TX (Pro Mini)?

Try another board type, such as Uno, which uses 115200 as the programming rate. (same 328P chip as the Promini.)
Do you have means to install a bootloader on the cards? Such as using a working Uno as an ISP? I’d suggest Nick Gammon’s bootload installer sketch.

Hi MotoDog!

I've had similar "issues" with my Pro Mini, and in my case it was a simple error... My setup did not have an automatic reset switch. I have to manually hold the reset button on the Pro Mini just prior to when the programmer is trying to access the board.

Perhaps your setup has this reset automatically triggered as part of the programming, as with an Arduino Uno, but I figure it's worth a try!

Good luck!