Sections:
APO3 Schematic. PDF.
The software is written in C and compiled using
CCS's PCM compiler. The source code and object code is made available under the GNU GPL license. You are free to distribute and modify the source code as long as you follow the terms of that license.
Software Files:
The APO3 case is an off-the-shelf enclosure
Polycase. It is the
LP-41F. We CNC mill the various cutouts in the APO3 case. The case manufacturer, Polycase, pad prints the label.
Modifications Mechanical Drawing
This drawing is alaso available as a larger PNG or PDF file.
The voltage threshold and the shutdown delay are configurable with DIP switches. The switch settings are show below and are also printed on the bottom of the circuit board.
Voltage Threshold
| SW1.1 | SW1.2 | Volts |
|---|
| Off |
Off |
11.8 |
| Off |
On |
12.1 |
| On |
Off |
12.7 |
| On |
On |
13.05 DEFAULT |
Shutdown Delay
| SW1.3 | SW1.4 | Minutes |
|---|
| Off |
Off |
0 |
| Off |
On |
5 |
| On |
Off |
10 DEFAULT |
| On |
On |
20 |
We sell a version of the APO3 that comes with pre-installed OEM T connectors. These are the connectors that are found on most
VHF / UHF mobile radios. Two 0.25" wide contacts perpendicular to each other. These connectors are available from amateur radio sources such as PowerWerx and hamfests, but there doesn't seem to be information on the Internet as to the original manufacturer part numbers. After multiple hours of research, APRS World has determined the OEM-T connectors to made by TE Connectivity and the following part numbers:
