FTDI <=> Arduino Pro Mini

[jocke4u]

Hi,

I have a couple of Arduino Pro Mini's and FTDI chip but have not used this programmer and to make sure I connect it correctly.

It seems to be straight ahead but a bit puzzled about CTS and GND since Pro Mini have two connections marked GND. Shall I just leave CTS or how to connect it?

From top:

Pro Mini      FTDI
--------      ------
GND      <=>  GND
???      <=>  CTS
VBUS     <=>  VCC
RX       <=>  TX
TX       <=>  RX
DTR      <=>  DTR

[marceltrapman]

@jocke4u CTS - GND is ok.
You can also check this by looking at the Pro Mini Schematic on the Arduino website.

[John]

If I have understand correctly having CTS to ground (Clear to Send to logical 0) means that the receiving device is (always?) ready for data reception.

[gregl]

@jocke4u
I've got a few of these "Funduino" "pro minis" - but ive never been able to send them a sketch. I stuffed around for ages but no luck.. even tried a different FTDI adaptor which i know works.

I now suspect they do not have an arduino bootloader installed! This dawned on me the other day....

If you get it to work, pls let me know!

I had to "upgrade" some of my Nano's the other day with Optiboot to get some additional memory so ill try to put the bootloader on one of these and report back.

[jocke4u]

@gregl
I just had to do a quick test and it seems that I have similar problem.
Tested all 5 pro minis I have with the same result

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x01

[hek]

Are you guys saying they ship pro minis without any bootloader onboard?

[jocke4u]

@hek said:

Are you guys saying they ship pro minis without any bootloader onboard?

I have no idea but @gregl suspect that.

[gregl]

@Hek - yes i think so.

I did not purchase mine from one of your "store" vendors...

[hek]

Ok,

Well... if anyone experience this from one of the recommended sellers let me know.

[gregl]

No luck - i am able to upload the Optiboot bootloader to them no problem,
but i cannot program ( upload a sketch) with any of my ftdi programmers.

I found this thread, same issue but with 3.3v - i had a quick attempt but i dont think its much different to what i was doing uploading (successfully) the optiboot bootloader.

Spent enough time on this junk....ill just stick to using Nano's...

Good luck!

[bjornhallberg]

Thanks for the warning. All the Pro Minis I've bought from Ebay / Ali have been the standard clone version thankfully and they have all worked out of the box, at least the way I've wired them. I did start out with the useless Silicon Labs CP2102 programmer because I didn't do my homework (the one where you have to solder a super-small wire from the chip or hold down the reset button manually). Not saying this would work here, there seems to indeed be something wonky with the Funduinos:
Sparkfun: Arduino Pro Mini 3.3v and FTDI 3.3v upload errors

For reference (the exact same APM board most of us have as well):
https://www.youtube.com/watch?v=Vawhrr4COjI
(or: don't do what I did - avoid non-ftdi programmers)

[jocke4u]

@bjornhallberg
Thanks for the info/video, I will do another try before they go the same route as for @gregl ....trash bin :-1:

@hek I also have bought these from another Aliexpress supplier

[jocke4u]

I did the FTDI loop back test and so far I see the programmer doesn't work so ordered the one referenced on MySensors

[bjornhallberg]

Seems you have the same programmer as I have though. But I guess you could have gotten a faulty one.

In retrospect I should have gotten one with a 3.3V/5V jumper instead of solder pads. Not that I need 5V.

[jocke4u]

FYI
I today received the new FTDI programmer referenced on this site (http://www.ebay.com/itm/320907184616) and now it works to program Pro Mini's :)

[daulagari]

@jocke4u Looking at the first picture of this thread it looks to me like you did not make a selection between 3.3 V and 5 V on your FTDI adapter.

You need to connect either the 3.3 V pad with the middle pad or the 5V pad with the middle pad.

[hek]

@daulagari

Yep you're probably right. Nice spotted!

[gregl]

i think on mine the solder pads are bridged... but i will check.

[jocke4u]

@gregl said:

i think on mine the solder pads are bridged... but i will check.

I am pretty sure it's the same (5V as default) for me but will double check.