DFRduino Fio not responding to upload anymore

Hello!

Seems that problems to program the Fio are quite widespread, wirelessly or not. See "Fio not responding ..."(Fio not responding, burning bootloader help? - Installation & Troubleshooting - Arduino Forum) and many other posts I read.

My problem is that all in a sudden I cannot upload programs to my Fio anymore. Although I was able to do so before, using both a Bluetooth module and the Arduino MiniUSB FTDI adapter. I once had problems after the BT connection went off while uploading. That got fixed by the next successful upload. This time I do not know what caused the current state. The program I tried to upload was slighty larger than the 30720 bytes available.

When resetting the Fio board by "wildly" pressing the reset button it may send characters on TX afterwards. But, none is legible, no matter what the baud rate is at the receving terminal program; it is 00 mostly.
Also, wenn starting an upload, usually the LEDs on the MiniUSB flicker visibly; this now is very weak, almost invisble.

Other tests conducted:
When connecting a serial terminal program, loop-back works for both connection types.
Programming another Ardunio board using the MiniUSB adapter works.
Connecting the MiniUSB's RTS to DTR on the Fio didn't change anything (I read that suggestion in another post).

My questions are:

  1. Is there a way to get another program loaded to the Fio board?
  2. What is the test to decide that the bootloader needs to be re-programmed?
  3. Could there be a hardware failure, resulting from the MiniUSB oprating at 5V (USB) and the Fio board just using 3.3V?

This is my firsts post. I am grateful for all other help I had from reading in this forum to get me going with Arduino and recall my electronics knowledge. But serial ports always were trouble, in a way...

Thank you for any help.
StRd.

  1. don't know anser sry see 2
    2)the only real way to check this is by trying to upload a sketch, if this fails it usualy is because of a driver that is faulty, wrong com port selected/ wrong board selected or a faulty bootloader
  2. can you still power the board? and does it still run the old programming?
    if yes and yes, there sould be no hardware problem (but i can't be sure without testing it myself by hooking it up to a programmer)
    ther atmega itself can handle 5V so the only thing that could have broken is the xbee if that woul work at 3.3v but i don't think this will be the case as i see there is some kind of regulator