interesting download problem....

H

hax

New Member
I'm programming an 18X with a Rev-Ed supplied USB to serial adaptor.


The download bar is blisteringly fast. Much faster than I was used to. But 70 percent of the time the download is corrupted and it says "error memory verification failed".
The other 30 % of the time it works fine.

Now, changing to the hardware serial port on the back of the computer and downloading works 100% of the time, but it is slower to download (by about 10 seconds).


I think in future versions of the editor software there should be a setting to limit the speed to a reliable download as my computer may be too fast for the picaxe. It's a new high end quad core gaming machine with 4GB ram etc...

Changing to a slower PC, but using the same USB to serial adapter, the download speed is not quite as fast (but still faster than the motherboard serialport), hence I think the problem is with the picaxe not keeping up with the USB serial port and/or the programming editor.


Very interested in feedback from others.
 
M

manuka

Senior Member
Interesting-although 4GB quad core gaming machines are out of my league. With such computing horsepower on tap I'm amazed that it still has a serial port! Given your new PC I guess this older slow coach you mention is just a tame old dual core plodder?

The 2 resistor PICAXE programming hack employed by Rev.Ed of course IS limited, but I doubt if it's been "speed camera" threatened like this before.
 
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B

BCJKiwi

Senior Member
Be very surprised if the PC speed is the cause of the problem.

The USB emulates serial and there are speed limits to both serial and USB which are far below the potential output speed of even a modest powered PC.

Anyhow, the business end of the system is serial. The chip and the programming editor automatically set the matching serial speed when downloading and that should determine the data rate, not the speed of the computer CPU or Bus.

The USB part of the circuit should be transparent to the the serial at the Program and at the chip.

Have you tried all the the USB ports as typically there is more than one type of USB Hub in the PC.
 
M

muckypups

Member
If the usb version emulates a com port, can't you specify the port speed in windows somewhere ? You could start low and increase until the errors start.

Alan
 
D

Dippy

Moderator
Hasn't something like this been queried before?
And it was confirmed that the programming Editor controls the speed. And that this would override any speed settings in Windows device manager etc.
Could there be a USB driver issue?

Probably all those games you have on it confusing it :)
 
Technical

Technical

Technical Support
Staff member
The baud rate is controlled by the ProgEditor and windows settings are not relevant as overwritten.

Processor speed is also pretty much irrelevant, the baud rate is fixed. There will be a small difference in download speed due to increased 'comparison processing' between bytes received, but that is almost irrelevant when compared to the delays caused by the baud rate and PIC memory write times.

What version software are you using and which windows/driver version? Which byte does verification fail on? It sounds more like a USB driver installation issue on the faster machine.
 
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