[amsat-bb] Re: LVB Tracker Box July/Aug 2007 AMSAT Journal

[Howard Long]

Hi Alan

> However, it is unclear to me what the page 4 " Ethernet interface capable"
> references.  Is it an alternative/addition to the USB and serial computer
> interface?  If so, is there a daughter board that must be added?   At what
> cost?  Is there a schematic for the DYI crowd? 

I apologise that until now I have never documented the Ethernet interface.
Tonight I reverse engineered the module that I built and tested about 3+
years ago. As you'll see it's not a rocket science module, being based on a
Lantronix XPORT device
http://www.lantronix.com/device-networking/embedded-device-servers/xport.htm
l, a couple of potential dividers to do the 5V to 3.3V conversion and a low
dropout regulator.

You will need a fairly decent heatsink on the main board's 5V regulator with
the Ethernet header device. ISTR that the LDO was fine without a heatsink.

http://www.g6lvb.com/Articles/LVBTracker/Ethernet/IMG_0057small.jpg
http://www.g6lvb.com/Articles/LVBTracker/Ethernet/IMG_0058small.jpg
http://www.g6lvb.com/Articles/LVBTracker/Ethernet/IMG_0059small.jpg
http://www.g6lvb.com/Articles/LVBTracker/Ethernet/IMG_0061small.jpg

You will see in the photos a couple of transistors. These are not used. You
should still endeavour to program the PIC on the motherboard using a real
hardware RS232 port rather than this Ethernet device or the USB header: this
is to do with the way that the handshaking lines are emulated. Once
programmed, remove the MAX232 and insert either the USB or the Ethernet
module into the header and the device will operate directly with your
favourite tracking software.

Like the USB header, the Ethernet uses COM port emulator software on the
host, although the transport to the device is IP.

Hope this helps.

73, Howard G6LVB