aprs-android-messaging

Build

You must have the Android SDK and NDK set up.

./gradlew assembleDebug

Message Format

1111111	1231234E	121234N	Message
Truncated unix time	Longitude	Latitude	Message

Truncated unix time

• Characters 0 - 6

• The two most significant and the one least significant value is truncated. This provides 10 second time resolution and ~38 months before it overlaps.

• Example:

  Unix time: 1504011673 Truncated unix time: 0401167

Longitude

• Characters 7 - 14
• 4 decimal precision. This provides ~11 meters resolution.
• Degrees are always 3 digits with leading 0s when less than 100 or less than 10.
• Decimal is dropped from the value.
• E appended for East, W appended for West.

Latitude

• Characters 15 - 21
• 4 decimal precision. This provides ~11 meters resolution.
• Degrees are always 2 digits with a leading 0 when less than 10.
• Decimal is dropped from the value.
• N appended for North, S appended for South.

Message

• Characters 22 - 256
• Message in ASCII characters

Acknowledgements

Based on code from PacketDroid and APRSdroid.