WiMo DB1NTO User manual

PicoAPRS
Developed by Taner Schenker
DB1NTO
Instruction Manual
www.wimo.com - 1- ©Taner Schenker

Inhaltsver eichnis
1. PicoAPRS.................................................................................................................................... 3
1.1 Assembly...............................................................................................................................5
1.2 Security Notes.......................................................................................................................6
Notes on battery disposal............................................................................................................6
2. Usage............................................................................................................................................7
2.1 General..................................................................................................................................7
Switching On.........................................................................................................................7
2.2 ainscreen............................................................................................................................7
Left Button............................................................................................................................ 7
Right Button..........................................................................................................................7
Automatic display of received APRS packets.......................................................................8
- Received position message................................................................................................. 9
- Received staus message......................................................................................................9
- Received message („S S“)................................................................................................9
2.3 enu structure (overview)................................................................................................... 9
2.4 enu details........................................................................................................................10
Power OFF.......................................................................................................................... 10
Last Heard........................................................................................................................... 10
essages............................................................................................................................. 11
APRS Symbol..................................................................................................................... 11
GPS Status...........................................................................................................................11
USB ode...........................................................................................................................12
Save Home pos....................................................................................................................12
TX Power............................................................................................................................ 13
TX interval.......................................................................................................................... 13
Beep.................................................................................................................................... 13
Timezone.............................................................................................................................13
yCall................................................................................................................................ 14
ySSID.............................................................................................................................. 14
Receiver.............................................................................................................................. 15
Frequency............................................................................................................................15
AutoPower.......................................................................................................................... 15
Autoclose............................................................................................................................ 16
Screensaver......................................................................................................................... 16
GPS Powersave................................................................................................................... 16
Contrast............................................................................................................................... 17
Comment.............................................................................................................................17
Info...................................................................................................................................... 17
Units.................................................................................................................................... 18
Reboot................................................................................................................................. 18
3. Specifications............................................................................................................................ 19
4. Troubleshooting........................................................................................................................ 19
www.wimo.com - 2- ©Taner Schenker

1. PicoAPRS
"The world's smallest APRS transceiver including T C" with a wide range of applications. Size like
matchbox, built-in GPS receiver.
The transceiver can be used not only as an APRS tracker and receiver for APRS data but also as
a T C (KISS protocol) for the computer.The graphic OLED display (128x64 pixel) displays
incoming APRS packets such as position messages, APRS messages (similar to SMS), and
status messages. For position messages, the distance and the direction of the sky are also
displayed. The four stations, including the distance and the cardinal direction, as well as received
messages, are stored and can be queried via the menu.
The own GPS coordinates can be displayed and the Pico-APRS can also be used as a GPS
receiver, e.g. for geocaching.
If desired, the GPS position can be stored permanently in the device. This is used when no GPS
position can be determined. The stored position is then only used to display the distance and the
cardinal direction of received stations. With the two control buttons and the versatile menu, the
Pico APRS can be configured and used entirely without a PC. In the default state, the device is
almost completely preconfigured. All you have to do is to enter the own call sign. The transmission
power is about 1 Watt (switchable to approx. 0.5 Watt). The position data are compressed in the
MIC-E format, in order to minimize the frequency as much as possible and to save the battery. Of
course, both received packets with MIC-E compression as well as uncompressed APRS packets
can be decoded and displayed.
With the built-in 850mAh LiIon battery, the device can be operated up to 10 hours depending on
the configuration. Depending on how frequently the position data is to be sent, whether APRS
packets are to be received, the GPS receiver should be switched off automatically when not in
use, and how often the screen can be switched off.
The receiver can be deactivated to significantly extend the operating time so that the Pico APRS
functions as a pure APRS tracker. In order to further extend the runtime, the built-in GPS receiver
is cyclically switched off and the screen saver is used (configurable).
The built-in Micro-USB connector not only allows the built-in rechargeable battery to be charged
and the firmware upgraded, the transceiver can also be used as a USB GPS mouse or T C on a
computer. This allows you to run your own APRS Digipeater or iGate!
The transmitter has a 7-pole harmonic filter for the suppression of unwanted sub-transmissions.
The main processor used is an ATmega processor (ATmega1284p) which is popupar on Arduino.
The current software occupies about half of the available memory space of the main processor.
Thus, there is still a lot of memory space for possible future function extensions available!
With a size of only 33 mm x 58 mm x 24 mm, the PicoAPRS resembles a matchbox. It weighs just
52 grams (without antenna).
Ideal to have the device always with you, e.g. Hiking, biking, motorcycling, skiing, on a boat or in
the air.
www.wimo.com - 3- ©Taner Schenker

The unit is supplied as a kit.
The two circuit boards must be mounted on each other and installed in the housing. The circuit
boards themselves are completely equipped and tested.
Delivery:
•Housing with keys
•Circuit board set, tested and tested
•instruction manual
•LiIO battery
•Pinheader for GPS board
www.wimo.com - 4- ©Taner Schenker

1.1 Assembly
1. Insert the two buttons. 2. Insert the board with the antenna socket
in advance. Then slide the board down so
that the USB socket is inserted into the
housing.
3. Insert the spacer. 4. Insert the GPS module.
5. Install the battery and fold the cable one
time to the left of the battery.
6. Slide the cover from below. Place the
groove on the bottom of the unit.
www.wimo.com - 5- ©Taner Schenker
No effort is required for the assembly! All components can be used very easily. If
something is difficult, please check the cause and do not try with "violence" to protect
the parts from damage!

1.2 Security Notes
- The unit is not waterproof and is not protected against splash water. Please use it only in a dry
environment.
- Do not expose the appliance to excessive heat (for example, a parked vehicle in high sunlight).
- Do not use any damaged components.
The used battery stores energy with a high density. Incorrect handling of the battery can lead to
dangerous situations. Please observe the following precautions regarding the handling of the
battery.
- Do not open or attempt to repair the battery
- Do not short-circuit the connections
- Do not expose the battery to high temperatures or burn it
- Do not expose or dispose of the battery
- Do not charge the battery when the battery is warmed or near sources of heat.
- Do not use a defective or damaged battery
- Do not charge the battery with other chargers
- Do not place the unit on a flammable base
Notes on battery disposal
In connection with the distribution of batteries or with the delivery of devices containing batteries,
the supplier is obliged to inform the customer of the following:
The customer is legally obliged to return used batteries as end users. It can return old batteries,
which the supplier has as a new battery in the assortment or led, free of charge at the dispatch
warehouse (dispatch address) of the offerer. Batteries and accumulators must not be disposed of
in household waste.
The symbol according to §17 paragraph 1 BattG (german laws) and the signs according to §17
paragraph 3 BattG have the following meaning:
Pb = Battery contains more than 0.004% weight of lead
Cd = battery contains more than 0.002% cadmium
Hg = battery contains more than 0.0005 mass% of mercury
www.wimo.com - 6- ©Taner Schenker

2. Usage
2.1 General
The transceiver has only two buttons due to the very small dimensions. With these two buttons,
PicoAPRS can be fully operated and configured. The operation is very simple.
PicoAPRS can only be operated with the battery connected.
Switching On
To switch on, press one of the buttons for at least 2 seconds.
2.2 Mainscreen
To enter the menu, press the left button (labeled "Menu") while PicoAPRS displays the main
screen. See the following illustration:
Left Button
The left button is used within the menu to jump to the next menu item or to the next character to
be changed (for example, for call sign input). In this case, the button in the display is labeled
"next" (see menu items below).
Right Button
Use the right button to change the currently displayed setting (for example, changing the character
on which the cursor is currently located) within the menus.
On the main screen, the right button is used to send a position message (labeled "beacon").
PicoPARS sends the position message as soon as a GPS position has been found. If GPS has
previously been deactivated automatically (GPS status display "OFF"), GPS is activated
automatically.
If mycalll has not been set to MyCall, "mycall" appears instead of "beacon". By pressing the
"mycall" key, you are taken directly to the menu item for setting your call sign.
www.wimo.com - 7- ©Taner Schenker

The following information is displayed on the main screen:
First line, from left to right: battery charging icon, alternating with charging current in mA, TX /
RX status, GPS status, battery voltage
Second line: Time (time zone can be set via the menu) and your APRS symbol
Third line: speed in km/h (updated only while GPS is active) and above 3km/h your course in
degrees.
4th line: Label for the left and right buttons
Example screen:
Explanation of the above example main screen display:
- the built-in lithium-ion battery is fully charged. The battery
symbol is completely white filled and is permanently
embedded.
- "TX" – unit is transmitting. The TX indicator remains active
for a short time, even if the transmission has already been completed. Since transmissions can
sometimes only have a very short duration, this helps for better detection of transmissions.
When receiving data, an "RX" appears at this point.
If neither transmitting nor receiving a data packet, nothing appears here.
- Currently 7 satellites are used for the position determination.
- The battery voltage is approx. 4.1V (the voltage measurement is not calibrated!)
- Time 19:48:34 (hours: minutes: seconds)
- The speed is 1km / h
Further possible examples on the main screen:
In this example, the built-in battery is charging.
The battery symbol with arrow flashes during charging.
Automatic display of received APRS packets
When an APRS packet is received, the package is displayed automatically, unless you are within
the menu.
www.wimo.com - 8- ©Taner Schenker
The "*" symbol flashes during the GPS search.
If the GPS receiver has been temporarily deactivated for energy saving ("GPS Powersave"),
nothing appears at this point!
→ If the GPS receiver has been permanently deactivated after several unsuccessful GPS
searches for energy saving reasons, "OFF" is shown!

- Received position message
First line: call sign, SSID and APRS Symbol of the received
station
Second line: Distance in km as well as direction to indicated
station in degrees. Unless a valid GPS position is known (for
example inside buildings or when the GPS is deactivated due
to energy saving functions), a "~" appears in front of the
distance indication.
Third line: If a status text has been sent, this is displayed here as running text.
- Received staus message
If a pure status packet without position data is received, will display:
Status from:
Call sign
SSID
Status text
- Received message („SMS“)
First line: ote "MessageFrom"
Second line: sender of the message
Third line: Message text. (Circulation).
2.3 Menu structure (overview)
•Power OFF
•Last Heard
•Messages
•APRS Symbol
•GPS Status
•USB Mode (OFF / GPS / KISS T C)
•Save Home pos
•TX Power (High / Low)
•TX Interval
•Timezone
www.wimo.com - 9- ©Taner Schenker
All kinds of received APRS packets can be deleted by pressing one of the two buttons!
If a time has been set in the "Autoclose" menu, all received messages (with the exception
of messages) are automatically closed after this time has elapsed!

•Beep
•MyCall
•MySSID
•Receiver (O / OFF)
•Frequency
•Autopower
•Autoclose
•Screensaver
•GPS Powersave
•Contrast
•Comment
•Info
•Units
•Reboot
After the last menu point "Reboot" you get back to the main screen!
2.4 Menu details
Power OFF
Press the right button to turn off the transceiver.
Last Heard
Here, the last received four stations with distance in km and
direction in degrees are displayed. Stations already received
are updated when they are received again. Press "close" to
exit the menu immediately.
www.wimo.com - 10- ©Taner Schenker
If you do not press any button for 10 seconds in the Settings menu, the changes are saved
automatically and the menu will be exited. This does not apply if you want to display the last
heard, received messages, GPS position or while saving your home position!