Can't connect to megatune using a pcmcia serial card

steve r · Post by **steve r** » Tue Jul 04, 2006 11:05 am

Hi,

After my car sitting stationary for months while i finished my uni course I've finally got round to trying a pcmcia serial card that i bought of ebay ages ago. I have to connect a docking station to my laptop to get a serial out which makes the laptop bulky and the dock has disconnected a few times when data logging causing lost data so i thought i'd try one of these cards instead.

I've installed the driver with no problems and assigned it as com2 in device manager but can't get it to connect to the megasquirt. I've run the test connection in communications/settings for com2 and get 'no response'.

Everything to do with the card appears to be set to BPS 9600,data 8, parity none, stop bits 1, Flow control none, which i belive to be correct.

I've run hyperterminal and tested the connection to the megasquirt with the chip removed and pins 12/13 shorted as shown in the assembly guide. The keys pressed are echoed back to the screen so that part seems to be working. When the chip is replaced and i try to run megatune it won't connect.

If i switch back to the standard com1 port on the docking station then everything works fine, its just with the pcmcia card that i have a problem, its strange that the hyperterminal tests work but it won't connect fully.

Any ideas?

steve

Edit, there are FIFO buffers and a crystal frequency option on the pcmcai card options in device manager, do i need to play with those?

Mitch318i · Post by **Mitch318i** » Tue Jul 04, 2006 1:04 pm

Yes, FIFO buffers are important..
try very low settings for each.. you may have to experiment, but you should find a setting that should work.

steve r · Post by **steve r** » Wed Jul 05, 2006 9:33 am

Hi mitch,

thanks for the reply, i've played with the FIFO values and still had no luck,

i can adjust FIFO interrupt trigger levels for the transmitter and receiver between 0 and 127 and receiver FIFO Flow control thresholds for flow on and flow off between 0 and 127 for the card.

For the 'propper' com1 port on the laptop there are only controls for the transmit and receive buffers between 0 to 14 for the Receive and 0 to 16 for the transmit.

from the MegaSquirt Connection Troubleshooting Guide i have found this:

Finally, if you have a USB/serial adapter instead of a built in serial port:
In the INI file activated (see below), set:
writeBlocks = off ; Default is on.
interWriteDelay = 1 ; Becomes "interCommandDelay" if writeBlocks is "on"
You may have to play with the USB adapter settings in Windows for the adapter to get it to work (see Control Panel/System/Hardware/Device Manager). If there is a 'buffer' setting, set it as low as you can (often 1 or 0).
Make sure that your com port settings are correct for your serial port or your USB/serial cable. For example, change the baud rate (under 'start/Control Panel/System/Hardware/Device Manager/Ports (COM & LPT)') to 9600 for MS-I.

Is this valid for a pcmcia card or just a usb/serial lead?

I can't find writeBlocks = off in my ini file (MSnS-E 24s) any idea what line number it is?

thanks

steve