infinite loop firmware problem


By mistake i uploaded using Hyperterminal and XModem a dwl file compiled with another firmware
and now my Fastrack is rebooting continously (the led is on for 2 seconds and then it turns off , and this repeats forever).

How it was said on this forum I created a straight through cable from RS232 to modem and I connected
the BOOT signal with 10k resistor to GND .
I also have DwlWin .

I start DwlWin , I check under Erase , OpenAT Application I click start , it tells me please wait while…
it finishes and then it tells me Fatal timeout error : the target is no longer responding .

Am I doing someting wrong ? Or there is anoter posibility to erase the App from modem ?
Or my modem is really broken ?

Please help …
Thank you



You only have to connect the BOOT signal to ground while you power up the modem. The sequence should be something like this:

  1. Power off modem
  2. Start up DWLWin and configure correct version of firmware etc
  3. Click the start button in DWLWin - should display searching (or similar).
  4. Connect the boot pin to GND via 10k Resistor
  5. Power up modem - DWLWin should ‘find’ the modem
  6. Disconnect boot pin
  7. Firmware upload should continue

Also, are you using a USB-serial converter to do the download? I’ve had lots of issues with various types of USB-Serial converters and DWLWin. Try using a pure serial port on a PC for your connection and see how you get on.

ciao, Dave


I’ve actually had no problems - but there you go!



Lucky you! I’ve had the least problems with converters based on the FTDI 232R chips - but even then not all converters based on these chips behave the same…

Actually, the FTDI TTL-232-3V3 (as produced by FTDI themselves) have worked (perfectly) so far for me. These cables will plug straight into the UART1 pins on a Q2686 as the Q2686 UART 1 pins are 3V3 tolerant! Instant PCB connection with a six pin SIL header. Only down-side is that they are only a 4-wire serial connection…but I use these cables to program all my production PCB’s and all has been well so far :wink:

ciao, Dave



One thing I’ve noted is that it’s important to keep the RS232 cable short - especially at higher baud rates.

Yes, I thoroughly agree! :smiley: … 2R-3V3.htm
Buy online: … :+TTL-232R

:exclamation: But one important thing to note: UART1 is the only interface that is 3V3 tolerant! :exclamation:
All other interfaces are 2.8V or less!


also don’t forget the I2C bus, that’s also 3V3 tolerant