By ground sensor do you mean something that will be in the ground physically(like seismic detectors) ? Or deployed “on the ground” as in “in field” ?
Are you looking to utilize the android phone and it’s internal components only or is external hardware ok?
The Android phone component, is its only duty to relay information from a separate external device that is collecting this information?
Does the device need to withstand any particular environmental hazards?
How long of a operating time is wanted for this device ? As in battery life, is the option for recharging in field wanted?
Is the goal to produce a cheap monitoring / proximity node (device) that easily incorporates the connectivity of a android phone only to relay pertinent information?
Thanks for the questions. First ground sensor is a capability that can be emplaced on or in the ground utilizing the accelerometers and gyro that are resident in a smart phone. This would trigger the other phones to perform an action. The seismic capability would need to be able to be configured for sensitivity. This would be in a field/hostile environment. The capability would mainly utilize the android phones onboard capabilities, however, if necessary for seismic I would think that a probe of some kind would be acceptable. To give you an example of seismic sensitivity refer to the ShakeMe app that is referenced, of course understanding that this phone would not be in someone’s pocket or on a desk somewhere, but it does demonstrate the power of the internal components. The android set up in a mission setting, should have the ability to perform multiple functions. Example: A trail exists, people come and go, a phone is on one end of a same a 100 meter section of the trail at the other end there is another phone. In between there are three other phones. The first phone tips to the next phone that shoots a picture, registers a time stamp and geolocation, as the person proceeds down the trail the next sensor picks up the person with a seismic and shoot a picture, and so on until the person gets to the last sensor which also is triggered. Now flip it and a person walks the opposite direction and the same thing happens. This will demonstrate the flexibility of the capability with multiple sensors. Although the challenge does not specifically identify environmental impact on the sensor, it implied that the phone would need to be somewhat waterproof, capable of operating in high heat areas of operation. Additional requirements such as this would be required in phase II, right now it is proof of concept that the phones can do what we are asking it to do in the challenge. Battery life is a large concern, the sensors should be able to operate a minimum of 24 hours, recharging in the field for example a small low profile solar panel is acceptable. In regard to your last question the answer is yes. Ability to have a low cost easily assessable device that is capable of performing different mission sets using the onboard capabilities of the phone as explained earlier. I hope this answers your questions, please feel free to follow up. I look forward to your submission.