by 5B4AIY » 15 Jun 2012 12:13
Gentlemen,
I can confirm that the Belkin F5U409 USB-Serial converter simply will not work. I have tried to use this convertor myself and have had lots of problems with it. The USB to RS232 convertor I use has an FTDI chip in it, and that works under Win-XP/Win-Vista/Win-7. For Vista and 7 you will need to set the compatibility mode for the Ingenia loader to Windows XP/SP3, and will have to set the permission level to 'Run as Administrator'.
Inability to recopgnise via loader.
If you can get it to work at low speeds, then this is usually a symptom of a problem with the serial port on the Juma. I had this when trying to update the PA-100D with my firmware, and although it would work at 38K it would not at 115K. An examination of the data stream with my Tektronix sampling scope showed that the data transitions were very noisy, and not of the correct amplitude. The problem was eventually traced to the charge pump capacitors of the MAX232 chip. I seemed to have been sent an early revision chip which requires 1uF charge pump capacitors rather than the 0.1uF suuplied. I changed the capacitors, and that fixed the problem.
You can also see this if you have accidentally soldered the capacitors at 90 degrees to their correct orientation. I eventually diagnosed this problem with one correspondent who emailed me with similar problems, and it was only after he emailed me a JPEG image of his board that I spotted the mistake. In both cases the serial port will seem to work for terminal mode applications, but will not work for firmware updates.
If you have a scope, check the TRX-2 transmit data line - the data transitions should be abolutely clean with no noise on the tops of the data pulses, and the amplitude should be at least +6V to -6V or so depending upon the load of the receiving serial port. You can also perform a simple verification by plugging a stereo 3.5mm lead into the RS232 port and measuring the DC voltage on the tip, which is the TX data line. It should be about -9V, anything less is cause for suspicion.
It is possible to corrupt the boot loader if the RS232 port is not working correctly, I've done it, and then you have to both fix the problem and reload the complete firmware + boot loader package using the IDC port.
I have also had problems using USB to Dual RS-232 ports - in my case under Win XP and Win-7 I would get very unreliable and flaky operation. Indeed, using several different dual ports none of them have ever worked in an absolutely 'bullet-proof' solid reliable way, especailly under Win-Vista or Win-7. The only chipset that has never given me any trouble is the FTDI, and that can be updated from their website with the latest drivers suitable for Win-7. Using this chip I get solid reliable operation at 115k on Win-XP and Win-7 both 32-bit and 64-bit systems.
Regards,
Adrian, 5B4AIY