I searched for an answer and have come up empty handed. I cannot get the JTAG-USB to connect in AVR studio. My PC is WinXP. I can see the virtual port in the device manager and I have assigned it as COM2. The latest FTD drivers are loaded and they are reported as follows:
ftser2k.sys Ver 2.00.00.1
serenum.sys 5.1.2600.0
FTLang.dll Ver 1,0,0,1
ftserui.dll Ver 2.00.00.1
Within AVR studio, I choose Debug | Debug platform and device
→ JTAG ICE
→ ATMega169.
When I press Finish, it reports “The JTAG ICE was not detected. Check the serial cable and click Retry.”
I never see the JTAG-USB’s LED blink.
My target MCU is not connected (JTAG cable is unplugged). The instructions say that the JTAG-USB is powered from the USB, so that implies that the target does not supply power. However, the instructions also say it is optically isolated, so that would suggest that I need to supply power to the JTAG. I am not sure what is correct. I guess I need to open up the dongle and to see how it was designed. BTW, my target is a micro power battery device, so it cannot supply power to the dongle.
In the meantime, where am I going wrong?
Mystery solved. I opened up the JTAG dongle and found that the FTD USB interface was optically isolated from the JTAG interface. So, external power is required to operate the system. I added an external DC supply and AVR Studio now recognizes the JTAG.
FWIW, the Sparkfun web description says “No need for external power supply - takes power from USB port.” That seems to be an error, since external power is required to operate the AVR JTAG-USB.
But…how did you add an external power supply? My AVR-USB-JTAG doesn’t have a connector for an external power supply.
The external power is supplied through the JTAG connector at pin 7. Be sure to use the same voltage that the target MCU uses. Many development boards already have this setup for you.
My target uses a 3V coin cell (which would not last long if it powered the JTAG too). During debugging, I run the board (and JTAG) off a 3V Vreg instead.
I have an AVR Butterfly board which has the JTAG connector. AVR studio says the connection to Olimex USB Jtag failed as well. Can I simply connect +3v line (which I use to power the Butterfly board) to pin 7 of the Jtag connector?
Please help
Thank you
Than
I figured out what was wrong with my set up. I didn’t solder the Jtag header to my Butterfly board correctly (I soldered it on the wrong side of the board). flip it, connect power to pin 7 of the Jtag connector and I’m able to communicate with the AVR-JTAG-USB and the butterfly board correctly.
Thanh
I’m wondering if I’m not having a similar problem (see my post above yours in this same forum) with my serial JTAG connector.
I have the same symptoms, but the target device is on the olimex atmega128 development board. According to the sparkfun schematic the onboard JTAG connector has the correct pins wired up to 5v (4 and 7 i think), but I have no red LED on the connector itself and AVR studio sees nothing.
I’m not at home so I can’t verify the traces on the PCB…
Probably you got no Vcc on Jtag pin 7 or the header is not connected in a correct way. In my case, as soon as 3v voltage is applied to pin 7 & 4, the red LED turns on right away. It’s then blinking and turned off when AVR studio does the programming.
Nope, I have power on both… I sent sparkfun another email for a return. I think it may be D.O.A.