EA4EOZ
an amateur radio electronic enthusiast

HamGPS

Basic GPS with extended Locator for Ham radio use

( Looking for HamGPS for Java phones? Click here )

This program permits to you to know your current Locator with the aid of your GPS enabled Android phone. It also show you the bearing and distance to a target, who can be set using a locator or using latitude / longitude. This function is useful setting up, for example, a microwave station during a sked while portable.

It use no network connection or fancy maps, so it can work even in remote locations.

Using HamGPS

Just start the program and make sure you have enabled your GPS. Once your GPS has get a fix, you will see something like this:

Let me explain what are you seen using the image at the left as example.

The first line of text is your current UTC date and time. And the end of this line, you can find up to two symbols:

The symbol ⊕ means the map is locked: Drawn flat with north up. You can lock or unlock the map with a long press on it.
The symbol ☆ means the Keep Screen On setting is active, so the screen will remain on during all your operations with the program. You can enable or disable this function using Settings at the menu.

At the center you can see the sky map with all GPS satellites received by your unit displayed on it. You will find also the Sun and the Moon if they are visible from your current location at the specific time.

The map has data on its four corners: Accuracy reported by your GPS, Used satellites to compute your position vs. received satellites, your current speed and your (device's) current bearing.

Bearing can be followed by a letter G if GPS bearing is used, or M if magnetic bearing without magnetic declination correction is used. If no letter is shown, it is true bearing.

If you have set a target location, you will see a text line with the distance and bearing from your actual position to that target. Also a big arrow will appear on map pointing to your target. Note if you set target using a locator, HamGPS will use as target point the center of the specified square.

Under the map you will find a group of bars displaying each satellite signal and if it is active (solid color) or not (translucid). If your screen is large enough these bars will be always displayed. If not, you can toggle them by tapping on the screen with your finger. The color of the bar (and satellite itself) represents the current satellite signal using this color scale:

minimum signalmaximun signal

At the bottom of the screen you will see your current Maidenhead locator and height over sea level (really over GRS80 reference ellipsoid ). You can tap on this button to switch to various formats of latitude and longitude representations.

Menu entries

In the application menu you can find these options:

Set target by locator: Set your target using Maidenhead locator. You can use 4, 6, 8 or 10 digits, for example: IN72, IN72DE, IN72DE34 or IN72DE34FG are valid locators for HamGPS.

Set target by lat/lon: Set your target using its latitude and longitude. All common formats for angles are accepted, for example:

Angle	HamGPS input
25.123456°	25.123456
25° 35.3453'	25 35.3453
25° 35' 18"	25 35 18
25° 35' 18.72"	25 35 18.72
-25° 35' 18.72"	-25 35 18.72

Just separe degrees, minutes and second with spaces.

Settings: Application settings. See below.

About: Self explanatory.

Settings

In the Settings menu you can tweak how HamGPS will work for you:

General settings:

Speed units: Select unit for speed and distance. You can choose between km/h and km, miles per hour and miles or knots and nautical miles.

Altitude units: Select the unit for altitude. Meters or feet.

Keep screen on: Keep the device screen's turned on while HamGPS is running.

Sky map settings:

3D view: Display a floating map using your device's magnetic and acceleration sensors.

Use GPS bearing: Use bearing values from your GPS instead your device's magnetic sensor. A GPS device can only give useful bearings if it is on movement, for example, inside a car.

Display all cardinal points: If active all four cardinal points will be drawn on the map. If not, only North will be drawn.

Display GPS satellites: If active, GPS satellites will be drawn on the sky map.

Display sun and moon: If active, sun and moon will be drawn on map

Display day/night colors: If active, sky map colors will change during night.

Frequently Asked Questions

(Q) I can't upgrade from HamGPS 1.3 to the new version

(A) You installed HamGPS 1.3 from this webpage and now version 1.4+ uses a different certificate (needed for Market), so your Android device refuses to upgrade. You only need to delete HamGPS 1.3 before upgrade or install the new one.

(Q) HamGPS seems to drain my battery.

(A) Unfortunately it is true. Having GPS and sensors working together and a real time graph in the screen updated several times per second to give somewhat real movement requires intensive CPU, so battery usage is high, just like action games. My recomendation is to use HamGPS only when needed or with a external powered Android device ( = connected to the charger) if you will use it intensively.

(Q) The north mark in the sky map does not reflect the real north.

(Q) The 3D map response is weird when I move my Android device.

(A) Magnetic sensor in Android devices does not seems to be very reliable from my experience, but anyway here are some tips:

Make sure you are far away from magnets, large metalic structures or alternating magnetic fields produced by electrical equipment. If in doubt, test it outdoors.

Check if your magnetic sensor need recalibration. This procedure is different from device to device but many Android devices recalibrate its magnetic sensor if waved in an 8 shape for a while in different axes. Check Google for your specific device.

(Q) I can't find HamGPS in Market.

(A) Searchs in Market are filtered so only applications that will run on your device will be shown. To run HamGPS your device needs:

Compass / magnetic sensor

Accelerometer sensor

Real GPS. Maidenhead 10 digit locators are only a few meters wide. Getting location from A-GPS devices or using cell towers or WiFi hotspots does not provide enough precission.

(Q) My Android device does not have / support Market. Can I download the APK file?

(A) Yes, use this QR code to download it or click on it to download.

Changelog

Current Version is 1.7
Larger target arrow.
Added access to GPS setting from HamGPS.
Version 1.6
Small patch to solve corrupt data from bug in version 1.4
Version 1.5
Solved a NumberFormatException appearing from time to time entering a target locator.
Version 1.4

Added 3D map view.

Added preferences screen.

Added target location using locator or latitude / longitude.

Application is now available in Android Market.

Version 1.3

The program has been moved to the Android platform.

Version 1.2

Full rewrite of source code and new user interface.

Last version for J2ME devices.

Version 1.1

Better NMEA support: After some time testing HamGPS with different Bluetooh GPS, they do not implement all the sentences in the same way. Solved

Improved $GPGSV sentence interpretation: There are some problems with some GPS so, the 4th and 8th satellite does not showed signal (as seen in the photos). Solved

Better keyboard support: Not all phones maps their keys in the same way, so now HamGPS uses the Game API to read the keyboard keys: UP, DOWN and SELECT / FIRE / ENTER, this is usually the phone's joystick. Solved

Loop optimizations, so HamGPS are about 1 Kb smaller.

Version 1.0

First public release

About HamGPS

HamGPS is free. Copy it, execute it and do whatever you want with it.

Miguel A. Vallejo, EA4EOZ

Back to the index page