Quote from: Jan Waclawek on January 23, 2008, 12:18:01 AM
And did using the DC power separate from USB alleviate your problems?
---
I don't quite understand what you mean "the bootloader destroys itself". Please comment.
JW
A separate DC power doesn't solve the problem, in order to work I have to make changes to the development board: include a reset to the FTDI chip or include a oscillator based on an external crystal.
The bootloader has code in "user" program memory ... that code deletes itself after determining the baud rate, it does it very well from any garbage generated from the FTDI ... if the chip gets garbage from the serial port or Vdd is not 5.0V, that portion of code is deleted and a parallel programmer is required to recover. Furthermore bootloader v7 is only available for ISP upgrade, only v5 is available from NXP site.
What I will do asap is to modify the bootloader in order to be able to use 40 chips, or redesign a smaller development board with standard RS-232.
For the boards that I have now, and still intend to use (we have around 150 of these), I will buy parts from other manufacturer.
I attached the schematic of the circuit.
Regards,
JCabral