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Topic: FTDI cable upload problem (Read 2384 times) previous topic - next topic

fungus


Fungus - I uninstalled the drivers Windows assigned then manually installed drivers that I downloaded from ftdi.com but upon closer inspection found that they were exactly the same drivers.


When I had a similar problem it wasn't the drivers causing the problem, it was the way I installed them. I don't remember the 'correct' way but I know it wasn't the obvious way. I'm sure google can help.



Where is your crystal?  I don't see one in your schematic.  It won't work unless you set your fuses for internal clocking.  Otherwise you will need to add an external crystal(w/caps) or a resonator.


That wouldn't explain the lack of flashing LEDs on the cable.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

retrolefty

Hanging a LED/resistor off the auto-reset pulse signal is a very unproven concept that I've never seen applied before. The auto-reset circuit is a fragile enough thing to begin with without loading it down.

I would disconnect that led until you have a working auto-reset upload working and only then rehook up the led to see if it prevents uploading or not.

Lefty

oric_dan

#17
Mar 07, 2013, 08:33 pm Last Edit: Mar 07, 2013, 11:24 pm by oric_dan Reason: 1

Oric_dan -  firstly I checked the voltage between the Gnd and power leads of the FTDI cable and it is 5.46 volts. I changed the port settings to set RTS on close but still no successful upload. I then connected a series resistor and LED to "cable side of the 0.1 uF blocking cap" as per attached circuit diagram. The LED doesn't light while the code is compiling then as it starts to try and upload, it briefly flashes on / off then comes back on while the code tries to upload. It then goes out when the
avrdude: stk500_getsync(): not in sync: resp=0x00
error displays. From my rudimentary electronics understanding does this mean that seeing as the LED on the RTX line has it's anode to + 5V  that the RTX line is low when the LED is illuminated ? Does any of this information help to ascertain what is happening here or could someone just point me to an online store, with reasonable postage rates to Australia, where I  can purchase a FTDI cable that works out of the box, so to speak. Thanks again to you all, for your help, Pedro.

Sorry for the confusion - for the info I mentioned, I had the Led wired the other way around [and
I also used a MUCH larger series-R value], so it would work backwards to what you show in your
schematic.

lefty brings up a good point about loading down the RTS/DTR line in the cable, but it worked just
fine for me with uploading sketches. I don't run it that way normally, but just wanted to indicate
what the operation of RTS versus DTR looks like, to help identify how your cable might be working.
[lefty seems to be my online "conscience", LOL].

Buying 3rd party stuff from who knows who and who knows where is always a crap-shoot. Worse,
that so many of these ebay sites don't provide anything in the way of real documentation. What's
with that!

Pedro147

oric_dan

Yes I think that I will just put the purchase of this cable down to experience and buy one from a more reputable vendor. Am I correct in assuming that is you have a 328 with a bootloader burnt to it , appropriate to the board that you wish to use it in, that you only need a FTDI cable. Whereas if you don't want a bootloader on the chip (for space saving considerations) that you need an AVR programmer, or use the Arduino as a ISP.
http://www.pedroduino.com

retrolefty


oric_dan

Yes I think that I will just put the purchase of this cable down to experience and buy one from a more reputable vendor. Am I correct in assuming that is you have a 328 with a bootloader burnt to it , appropriate to the board that you wish to use it in, that you only need a FTDI cable. Whereas if you don't want a bootloader on the chip (for space saving considerations) that you need an AVR programmer, or use the Arduino as a ISP.


That is correct, you need a bootloader installed onto the target chip first before serial communication can work for loading sketches, or a ISP programmer to burn a sketch without having a bootloader on the target chip. The IDE now allows either method to be used, normal upload button for serial/bootloader method or the File/upload using programmer menu option for using a ISP programmer.

Lefty

Pedro147

Thanks Lefty. Gee the tutorage you guys are providing me with must be doing something  8)
http://www.pedroduino.com

hiduino

Not to drag this on, but did you try just a loop-back on the FTDI cable?  All you need is to jumper the White-Rx to Green-Tx pins on the cable, nothing else connected.  Then use a serial monitor program to the COM port.  Then it should echo back whatever you type on the keyboard.  This would at least show if the FTDI cable is actually working or not.


Pedro147

#22
Mar 09, 2013, 12:35 am Last Edit: Mar 09, 2013, 12:48 am by Pedro147 Reason: 1
hiduino -  I bridged Tx and Rx on the cable > plugged it into computer > opened IDE and selected correct port >  opened serial monitor > typed message > enter > message showed on serial monitor
http://www.pedroduino.com

hiduino

No sketch, just open up the serial monitor from the IDE.  Or use some other serial console software.


Pedro147

hiduino - see reply #22 (I edited before I realised you posted a reply)  8)
http://www.pedroduino.com

hiduino

That's a positive sign that the FTDI cable appears to be working correctly then.

So the problem of programming the 328 is elsewhere.  Which leads back to how are you clocking the 328? What fuse settings were used, internal or external?  If you used the Uno settings then it is probably looking for an external crystal on pins 9 and 10.


oric_dan

Still need to figure out what the pesky "RTX" pin is doing.

Pedro, I have a couple of different pcbs I worked up myself, and use the FTDI cables+Friend
with. Too much trouble to mess with USB chips on every one of my own boards, so I have one
FTDI cable and one FTDI Friend used for many different projects. Plug in when needed. I use
RS232 in essentially every program, so the FTDI comes in real handy. It kind of pays to buy
one you know will work without hassles if you're only buying one of each.

I always use bootloader chips and FTDI for uploading, but could use the ICSP header or SPI pins
if I had an AVR programmer - one is on order now. I have both 328 and 1284 boards, and the
same FTDI cables work with all of them, and I didn't have to solder nasty smt USB chips on
any of them.

CrossRoads

"I didn't have to solder nasty smt USB chips on any of them."

Hear hear! I'm all for that too.
If I need USB/Serial on board now I use one of these
http://www.mouser.com/Search/include/LargeProductImage.aspx?path=mikroelektronika/lrg/usb_uart.jpg


I did pick up some of these to glom onto a board also if desperate (or cheap) with Lefty's DTR mod for reset with downloads.

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Pedro147

hiduino - "you are the man"


Where is your crystal?  I don't see one in your schematic.  It won't work unless you set your fuses for internal clocking.  Otherwise you will need to add an external crystal(w/caps) or a resonator.


I fitted a resonator to the circuit and now it works like a charm  8) When I followed Nicks tutorial I obviously misunderstood some aspect of it. Now that I think about it it all makes sense. Hindsight is a wonderful thing isn't it. I initially burnt the Uno bootloader to the chip  so when I tried to upload some code with the FTDI cable it was expecting to be using an external 16Mhz crystal, which wasn't there. I will have to apologise to the Ebay vendor for telling him he sold me a crappy cable...opps  8) Thank you to all you guys that came up with so many helpful suggestions, I have certainly learned quite a bit from this project.
http://www.pedroduino.com

Pedro147

Thanks to the help of you knowledgeable guys, now that I sorted out my FTDI cable problem, I made up this little board this afternoon. Hey, I won't put anybody out of business, but it works
8) Thanks again chaps.
http://www.pedroduino.com

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