Re: Minicom Connection Over Serial Port To PIC18F452 Device

Peter Arremann wrote:

On Thursday 06 April 2006 19:04, Robert L Cochran wrote:

I'm trying to use minicom on Fedora Core 4 to speak to a PIC18F452 chip
which contains a preloaded version of the Microchip TCP/IP stack. I
built the device myself from a kit; it is intended to be a small web
server. My objective is to assign an IP address to the RTL9019AS
ethernet controller. This can be accomplished over a setup menu that
appears in the minicom window. I suspect I have incorrect minicom settings.

Serial device -- /dev/TTYS0 connected to development board Max232 chip

setup for 19200 bps,8N1, software flow control, VT102 emulation

iptables service is stopped

When I connect, the setup program appears. It is just a menu with 8
choices. In fact, the setup menu sometimes displays itself twice.

I select an option say 2 to set the IP address. The device very
sensibily responds with the default ip address. I type in a new IP
address to reflect my actual network.

If I try to select 2 to check the default IP address, it again sensibly
responds with the new IP address that I just gave it. So far, so good.

Then I select the option to save the new IP address. a message is
returned which is usually the new IP address itself.

Attempts to ping that IP address fail.

Then I start the setup menu again in a new minicom window. The original
-- default -- IP address appears.

So it seems like the option to save the IP address isn't working right.
Things are apparently lost when I restart the device.

Is this a minicom software issue, or is it bad soldering on my part with
the actual device being tested? I'm quite willing to agree it may have
soldering issues.

Thanks

Bob Cochran

Is the IP address stored in an eeprom or a battery buffered ram? If the answer is eeprom, check your power supply. You need 2 different voltages to read and write to an eeprom. So its possible that on startup the firmware copies the IP into ram - that's where you modify it. It is actually not written back to the prom, so the next time you power on, you go back to the default IP... I doubt it has anything to do with minicom unless the display issue keeps you from seeing a "save" menu entry that you'd have to execute...

Peter.

I made a typo above -- the ethernet controller is the RTL8019AS.

Thanks

Bob