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Mounting the WiFi Switch in Your AV Bay
The WiFi Switch has two #4 holes for mounting in a AV bay sled. It's about 2.5" x .9" x 3/8",
so you'll need to make sure that you have enough room on your sled for it. It doesn't matter
which way you mount it, as long as it's mounted so the WiFi module is facing outwards.
There's a drilling template on the Eggtimer Rocketry web site, we recommend that you
download it, print it, and cut it out with scissors so you can drill the mounting holes accurately.
Our favorite mounting method is to use two #4 hex-head cap screws, about 3/4" long, and a
short (about 1/8") piece of ¼" i.d. rubber tubing to act as a spacer between the bottom of the
PC board and the sled. We hold it on with nylon-insert nuts... they don't work loose. If you
mount it like this, you can pretty much use whatever monster motor you may have on-hand
(like the infamous O5800, for example) without fear of anything coming loose, and the rubber
tubing makes a nice cushioned mount.
For rockets with somewhat lesser acceleration, we've used double-stick foam tape ("servo
tape"), it works just fine, but note that the tape isn't going to cover 100% of the bottom of the
board because it's not flat. Make sure that whatever surface you're attaching it to is nice and
clean; any dirt will get between the adhesive and the board, and keep it from sticking.
We generally recommend that you try to mount the WiFi Switch as close to the battery and
your altimeter as possible, and keep the wiring as short as possible. Small zip ties work really
well for tidying up the wires. Also, we strongly recommend that you zip tie the wires
connected to the WiFi Switch to your sled, to provide strain relief for them. In general, if a
wire can't move, it won't come loose. Enough said...
Note that large bits of metal in your AV bay will reduce the range of your WiFi switch, as will
metallic paint or carbon fiber body tubes. In most cases, the range will be good enough for you
to be able to operate the WiFi Switch from a reasonable distance, but you need to be aware of
this in case you're thinking that you can arm your 75mm minimum-diameter carbon fiber
machbuster sitting on the away pad from the LCO's table... it ain't gonna happen.
About Batteries for Your WiFi Switch...
The Eggtimer WiFi Switch is designed for a battery from 4V-16V, this fits in nicely with the
requirements of most hobby rocketry electronics. Since the WiFi Switch is designed to be used
with a variety of different batteries, we don't provide a battery connector; you'll need to get
whatever connector matches the battery that you're using. You CAN use a 1S/3.7V LiPo
battery with the WiFi Switch, note that the range may be slightly reduced compared to a larger
battery, but it should be more than adequate for most uses.
The WiFi Switch uses about 85 mA of current, so we recommend that you use a battery with at
least 300 mAH of capacity. That will give you about 3 hours of power, which should be
enough for almost all flights. Bigger is better. You CAN use a smaller LiPo battery, just
remember that the run-time will be less, so if you put a 200 mAH battery in your AV bay and it
sits on the pad for two hours, you may have an unpleasant surprise if your battery runs down
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