TNC-Pi User Guide
-7-
6/25/2017
Next install the two LEDs.
Ensure the shorter leads on the LEDs go through the holes closest to the flat
side of the LED outline.
The LEDs can be installed with bent legs so the LEDs point toward the front
of the board. This makes them easier to see when TNC-Pis are stacked one
on top of the other.
Install the transistor.
Ensure
you are installing the transistor rather than the voltage regulator…
they look a lot alike.
Now install the voltage regulator.
It goes in the three holes above C1. Install it so that the flat side of the
regulator faces away from U3.
Now install the 9 pin D-Sub connector.
Ensure that you push it all the way in so that it is flush against the board. In
addition to soldering the pins, you’ll gain mechanical stability by soldering
the pins that go into the large round holes on the sides of the connector.
Note: The D-Sub connector is optional. You can install the Radio
header to connect your radio to the TNC-Pi instead. See the section,
Connecting the Radio, for more information.
Solder in the 2 x13 header. With the TNC-Pi 2 kit this is a 2 x 20 header.
This part is somewhat tricky. It is the only part that is installed through the
bottom of the board.
a.
Start by installing this jumper on your Raspberry Pi and then
b.
Lower the TNC-Pi board onto the connector so that the body of the
connector is on the BOTTOM of the TNC-Pi board.
c.
Now you’ll need to solder the board about a half millimeter from all the
way down in order to prevent the board from bumping into the USB
connector on the Pi. It is not necessary to solder all of the pins. You
should at least solder the 4 pins in the corners (for stability) and the
first five pins on each row (pins 1
–
10).
Your best bet is to carefully trim the solder leads on the part of the TNC-Pi
board that will be on the USB connector side of the Pi to get as much
clearance as possible. You might also want to put a piece of insulating tape
