The Motus troubleshooting guide
Solutions to common problems can be found in the list below. Please contact us if you have any questions/concerns.
CAUTION! If you have a project, but have not yet registered with Motus and created a project, please do so now. See https://motus.org/data/login.jsp
CAUTION, again! If you have tags that you plan to deploy, but have not registered them with Motus, please do so now. See https://archived.sensorgnome.org/VHF_Tag_Registration
Motus Station Equipment, Hardware, Setup and Take Down: A bounty of information is currently available on the Sensorgnome website at www.sensorgnome.org.
Antenna angles sometimes shift, so it is important to inspect and track the details of every station configuration during every visit. If an element appears bent, fix or replace it. All changes to a Motus station must be tracked through their deployments in a registered Motus project.
Batteries will lose their charge very quickly if they do not get enough power from the solar panel. During the winter this is especially a problem, as short days combined with colder temperatures result in shortened or non-existent battery life. Projects operating when day length is less than 10.5 hours may want to consider using larger solar panels or rotating batteries, augmenting the panel with a charge from a wall socket. If day length and temperatures are adequate and the battery is still dying, the charge controller, solar panel, and all connecting cables should be checked for possible issues. Properly maintaining batteries over the winter by charging them periodically or connecting them to a batter maintainer or trickle-charge, is critical to ensure a long, healthy life.
Beaglebones/Raspberry Pi’s sometimes do not turn on (check for the blue blinking lights). If this occurs, try disconnecting and reconnecting the power cables. If this doesn’t work, try disconnecting the beaglebone/RPi from the battery and connecting to it with your computer via the USB cable. This sometimes takes a few minutes as your computer tries to connect. If neither of these work, check to ensure that the charge controller connections are in their proper positions (positive with positive, negative with negative). If they are switched, it is likely that the beaglebone/RPi has been fried and will need to be sent in for fixing. Other software issues may arise such as the inability to connect a running receiver to your computer, as a first step ensure that you’re running the most recent software version (available here) and conduct a re-image on your receiver as described here. Further unresolved issues should be posted to the sensorgnomads discussion group after checking that the issue hasn’t already been resolved on the forum.
Broken towers – Towers may occasionally break if not properly supported by guy wires or braces, or during periods of extreme wind. The break will usually occur just above the tripod, resulting in a bent or broken mast and occasionally broken guy wires and antenna elements. Remove all guy wires and antennas from the mast, replacing/fixing any broken elements or wires along the way. Remove the broken mast and replace with a new one, then assemble the tower as you would if it were a new installment. Be sure to inspect all tower equipment (rebar, battery, sensorgnome, etc.) for any other failures that may have occurred.
Charge controllers can be quite finicky. When connecting to the battery, solar panel, and sensorgnome (in that order!), ensure that positive and negative DO NOT get switched, as this can fry the controller, the gnome or both. If this occurs, it is best to get a new charge controller. If the battery is not charging and the solar panel appears to be working, the charge controller may be the issue and should be tested with a voltmeter or replaced.
Lost power – if the sensorgnome loses power while in operation, it should automatically restart itself when power again becomes available. If this does not happen, you will have issues when connecting to the gnome to download data. If you suspect this has happened, check the beaglebone – if all lights are on and not blinking, it has stalled when trying to restart. Disconnect from the battery and connect directly to the computer via the USB cable, it will draw power from the computer and reboot.
Rodents may occasionally chew on cables. To prevent this, zip tie extra cable to the tripod to ensure as little as possible is near the ground. For cables that must be near the ground (i.e. protruding from box itself), ensure all grass/brush is cleared away from the area and wrap cables in foil tape. Ensure the elbow where the cables protrude is packed with foam (pipe insulation works well) to prevent rodents, snakes and other animals from entering the housing box.
Sinking towers generally result from soft ground – the towers are quite heavy, and that weight is distributed on four relatively small areas. Scrap pieces of wood should be screwed onto the feet of the tripod if the tower is at any risk of sinking into the ground.
Solar panels should always face south (or as close as possible) and be angled between 45-60 degrees. Do not allow them to be obscured by trees, shrubs, buildings or anything that creates a shadow (even a small shadow can result in a large loss in power generation). Keep panels clean by washing during regular tower checks – a small spray bottle filled with soapy water and some paper towels work well. Ensure all connections are waterproofed, as they will corrode if exposed to water. If this happens, the wires can be cut, stripped, spliced and electrical taped to create new connections. Do not attempt to open the black box on the back of the solar panel.
Taking towers down – Occasionally one or two U-bolts will seize up or have the nuts rust into them, use a socket or crescent wrench to apply pressure and break the U-bolt if necessary. If guy wires or other parts are rusted out, bolts are missing, etc, have some spare parts handy to replace them, or keep a list of missing/broken parts for the next person/season.