# Eggtimer WiFi Switch - Is it usable as ONLY a switch?

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#### patelldp

##### Well-Known Member
I just placed an order for a pair of Eggtimer WiFi switches for use in my 54mm diameter three stage project. The altimeter bay for the upper stage will be about 6' from the base of the first stage which could make arming via a screw switch difficult. These switches are perfect for my application.

I will be using the switch to power my AIM Xtra 2.0 altimeter which will have a 2S 1000mAh LiPo. If possible, I'd like to reserve that battery solely for the AIM and power the WiFi switch with its own 1S 400mAh LiPo. The AIM really needs its own dedicated battery as it has a significant current draw and skimming some off to power a switch would greatly reduce transmission time.

Is it possible to use the WiFi switch solely in place of a screw switch with its own dedicated battery, or does one need to run the altimeter battery through the switch?

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Like every other electronic switch that I know of, the WiFi Switch is powered by the altimeter's battery and turns on or off the altimeter by providing or cutting power to the altimeter. It's not like a mechanical switch which provides a mechanical low resistance path between the battery and the altimeter. The WiFi Switch will work with a 1S LiPo, but it's marginal; you're much better off with that 2S battery. A 1000 mAH 2S LiPo will run both your WiFi Switch and the AIM Xtra for several hours, but you may want to get a larger battery. Look at the batteries used for Airsoft rifles, they're long and skinny and fairly easy to use with minimum-diameter rockets like yours. This one is 2000 mAH, that should last you all day: http://www.hobbyking.com/hobbyking/...tech_2000mah_2S_15_25C_Lipo_AIRSOFT_Pack.html

#### blackbrandt

##### That Darn College Student
Like every other electronic switch that I know of, the WiFi Switch is powered by the altimeter's battery and turns on or off the altimeter by providing or cutting power to the altimeter. It's not like a mechanical switch which provides a mechanical low resistance path between the battery and the altimeter. The WiFi Switch will work with a 1S LiPo, but it's marginal; you're much better off with that 2S battery. A 1000 mAH 2S LiPo will run both your WiFi Switch and the AIM Xtra for several hours, but you may want to get a larger battery. Look at the batteries used for Airsoft rifles, they're long and skinny and fairly easy to use with minimum-diameter rockets like yours. This one is 2000 mAH, that should last you all day: http://www.hobbyking.com/hobbyking/...tech_2000mah_2S_15_25C_Lipo_AIRSOFT_Pack.html
Thanks for linking to that battery! I've been looking for a battery for my 38mm MD.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Thanks for linking to that battery! I've been looking for a battery for my 38mm MD.
Don't know if that one will fit in a 38mm, but they have a 1000 mAh that's basically half of the pair... that one is 20mm x 11mm, so it should work.

#### patelldp

##### Well-Known Member
Like every other electronic switch that I know of, the WiFi Switch is powered by the altimeter's battery and turns on or off the altimeter by providing or cutting power to the altimeter. It's not like a mechanical switch which provides a mechanical low resistance path between the battery and the altimeter. The WiFi Switch will work with a 1S LiPo, but it's marginal; you're much better off with that 2S battery. A 1000 mAH 2S LiPo will run both your WiFi Switch and the AIM Xtra for several hours, but you may want to get a larger battery. Look at the batteries used for Airsoft rifles, they're long and skinny and fairly easy to use with minimum-diameter rockets like yours. This one is 2000 mAH, that should last you all day: http://www.hobbyking.com/hobbyking/...tech_2000mah_2S_15_25C_Lipo_AIRSOFT_Pack.html
I appreciate the help on this. Believe it or not, I'd actually want a battery that is essentially a square cross-section and fairly short in length. I haven't done the math as I don't have the WiFi switch in hand yet, but one side of the board will be dedicated to the AIM Xtra and the other side will have the battery and switch stacked axially. All of this will be in a 54mm coupler that is a total of 6" long, so less with minimal bulkhead step engagement. I've done this before but with a Missile Works screw switch.

Ideally, I'd power the switch with a dedicated battery and the altimeter with a dedicated battery, specifically my 1000mAh battery that I know is usable for multiple flights in one day. If I have to power both with the same battery, I'll have to get a larger battery.

#### ksaves2

Is you are running a 1000mah battery, you ought to be good running your AIM and the WiFi switch from it. Unless it's going to be sitting on the pad a long time. The other thing you could consider is ditch the AIM and
get a $40.00 Quantum. Will get rid of an extra electronic device and leave room for a bigger battery? You plug the Quantum in, button up the ebay and it's ready to be activated by your Wifi/browser enabled device. A lot simpler wiring if you ask me. Kurt #### cerving ##### Owner, Eggtimer Rocketry TRF Sponsor TRF Supporter The Xtra has GPS tracking... it's like a TRS. I'm sure he's got the whole setup, so he want to use it. #### patelldp ##### Well-Known Member Is you are running a 1000mah battery, you ought to be good running your AIM and the WiFi switch from it. Unless it's going to be sitting on the pad a long time. The other thing you could consider is ditch the AIM and get a$40.00 Quantum. Will get rid of an extra electronic device and leave room for a bigger battery? You plug the Quantum in, button up the ebay and it's ready to be activated by your Wifi/browser enabled device.
A lot simpler wiring if you ask me. Kurt
I am planning a three stage rocket. This will require the unit to fire a separation charge and control 3rd stage ignition. The AIM Xtra (accelerometer based) does that AND provides GPS telemetry and tracking.

The rocket will have a Raven in each booster (to control stage separation and fire a deployment charge) and the AIM Xtra in the sustainer.

#### patelldp

##### Well-Known Member
I think I found a battery that will work. Understanding that this bay will be very tight, here's a 1500mAh battery that is approximately the correct form factor that has the same connectors to my current 1000mAh battery:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=26564

71 x 33 x 19mm (2.8" x 1.3" x 0.75")

As long as the WiFi switch is <2.875", I should be able to make this all work.