The Motus array (and broader sensorgnome network) have experienced numerous outages
over the past year. Here are some notes on what needs fixing.
Software
- the 2015 Aug 27 software update has been running on several SGs at Acadia, Turkey Point,
and Falconer (ON) for severaldays and seems stable. It will be a replacement for the broken
update of 28 July, and will address the same issues: funcubes stopping for various known and unknown reasons,
and SGs seeing no devices at all because a USB cable got jiggled without the unit being
rebooted. This update will reprogram any attached funcubes to sample at the 48 kHz rate,
which makes the unit's web interface more responsive. This update can be applied to any
unit running a software version from late 2014. If the unit is running a version from May 2014
(or earlier!) it is probably best to re-image the unit with today's release. Re-imaging is also
recommended if you're unable to connect to a unit's web interface. Instructions
are on the software releases page.
Power Reliability
- a major issue! This will be addressed by doubling solar panels and/or batteries.
- solar panels should be wired in parallel to each other (i.e. connect + to +, and connect - to -).
- batteries should also be wired in parallel to each other (i.e. connect + to +, and connect - to -).
- the SG should continue to be attached to the load terminals on the solar charge controller,
and not directly to the batteries or the battery terminals on the solar charge controller.
- solar panels should face due south, or somewhat westward of that if due south
is not possible.
- the ideal tilt for panels is a bit of a guessing game. At the equinoxes (March 21,
Sept 21) the noon sun is LAT degrees down from straight overhead, where LAT is the latitude. E.g.
at 40 degrees North latitude, the equinox noon sun is 40 degrees down from overhead, or, equivalently,
50 degrees up from the horizon. In late September, we're still getting quite a bit of sun, but later
in the season, when the sun is lower, we want to make sure to get more of that. So I'd recommend
dropping the panels another 10 degrees toward the horizon. This is because at the winter solstice, Dec. 21,
the noon sun is 23.5 degrees below where it is at the equinox, but we want to make sure peak migration
in Sept. to early Nov. is well powered, so we don't tilt all the way to the solstice noon angle.
GPS Placement
- we've had several instances of GPS cables being bitten through or corroded
- the GPS is critical, because it sets and maintains the system date/time.
- testing at Acadia has found that both the USB GPS (BU-353-S4) and the
GPS cape with external puck antenna can function from inside the Action
Packer box or the Pelican case, but only if mounted as follows: - the GPS puck (USB or cape antenna) will be attached to the inside of
the lid of the outermost weatherproof container: - if the Pelican case is enclosed in an Action Packer, attach the GPS puck to the Action Packer lid
- if the Pelican case is outside, without an Action Packer, attach the GPS puck to the Pelican case lid
- clean the area on the inside lid where the GPS will be taped, so that the tape sticks reliably
- the GPS puck must be oriented flat, with its "active surface" pointing straight up toward the sky:
- for the USB puck, the "active surface" is the side labelled BU-353-S4
- for the cape puck, the "active surface" is the more rounded, non-magnetic side
- the GPS puck is taped into lid using foil tape (e.g. this kind). Do not use plastic duct tape - metal is required.
- if attaching to the Action Packer lid, use an 8" length of tape and run it across a couple
of the ribs, so that the cable comes in along a groove, as shown here:
- if attaching to the Pelican case lid, use a 6" length of tape and attach where convenient.
- smooth the foil tape firmly against the lid, and against the underside of the GPS.
- after mounting the GPS inside the case, close it all up, restart, with the case positioned as it will be
after you leave
- restart the SG
- attach to the SG's web interface and wait until the GPS gets a lat/lon fix and has set the system clock.
If this has not happened within 5-10 minutes, you will probably need to try a different configuration.
- Caution: this scheme will not work if you are using a heavy object to weight down the lid of the Action Packer,
as this will block GPS signals. You'll need to find another way to keep the Action Packer secure, such
as running wire through the side latches and fixing those to the ground.
- Caution: if water pools on the lid of the Action Packer or Pelican case, it may impeded GPS function. If possible, position
this outermost box so that it has a slight tilt and will shed water.
