It has been over a year since the last update, but we're still here. Today we announce the release of a new Android app, Surveyor Tools Free. It is basically a theodolite, compass and GPS rolled into one useful app. Click the link at left to check it out!
Today we released a major update to our Working Scale app. We added a second, completely independent method to measure mass. Previously, the app determined the unknown's mass by measuring the angle of tilt of the Android device. The new method makes use of the fact that the oscillation period of an object attached to a spring depends on the mass of the object.
By placing an Android device at the end of a meter stick or yard stick partially overhanging off the edge of a table, you can measure the mass of a small object. Working Scale accomplishes this feat by accurately measuring the oscillation period.
Shown in the picture is a Galaxy Nexus phone at the end of a yard stick with two US quarters. The quality of each measurement is reported as 'good', 'fair', or 'poor'. This feedback is helpful in deciding if the measurement should be repeated.
At the request of one of our Precision GPS app users, we have added an option to display UTM coordinates in Precision GPS Pro. Let us know if there are other features you would like to see included in these apps.
Yesterday, I noticed a couple of old ice packs in my garage. These are typically used for keeping shipped perishable items cool during transport. The type of ice packs I have consist of liquid in a sealed plastic bag. I immediately thought that these would serve as a great platform for testing our 'Working Scale' app on Android devices. So, we setup a stack of two ice packs and set our Nexus 7 tablet on top (see picture).
The results of a few tests are very encouraging. The tablet rests more stabily on the ice packs than it does on a slightly inflated zip-lock sandwhich bag (which was our previous favorite platform). Also, stacking two or more ice packs increases the sensitivity of the tablet to mass. If you have some ice packs in your freezer that you aren't using, try them with 'Working Scale' and see how they work for you.
In case you haven't noticed yet, we published version 2.0 of the free version of 'Working Scale' yesterday. This is a major update. We have tweaked the app engine to give more stable readings, and we fixed some UI issued for tablets. We hope that this improves the accuracy of the measurements for all Android devices. We know that it takes some care using this app to get good results, especially when you are working near the lower mass limit for reliable mass determination (about 5 grams).
Yesterday, Science with Android published its latest Android app, Accurate Thermometer Free. You might ask "Why another thermometer app? Aren't there enough in the Android stores?" True, there are many apps that have "thermometer" in their names, but do they provide an accurate reading of the ambient temperature?
Thermometer apps determine temperature either from information from the Internet specific to your location, or else they use the built-in battery temperature sensor. Accurate Thermometer Free uses the latter approach. So, what makes it different from other Android apps that use the same sensor?
Accurate Thermometer Free only counts a temperature measurement as accurate if the Android device has been sitting motionless with the screen off for at least 20 minutes. This ensures that the device has been been held in your hand or kept in your pocket for that period. It also requires your device to have been asleep. Only then has the device had sufficient time for its temperature to come into near equilibrium with the ambient environment. Any small remaining difference between the device and its surroundings is taken into account with a simple offset. The app includes a default offset value, but you can change it with a simple calibration procedure.
A pro version of Accurate Thermometer Free is in the works.
This is our first blog posting on our weeks old web site. Come here for the latest news on our apps, contributions from our supporters, and news related to doing experimental science with Android devices. We hope to post on a semi-regular basis. Please email us at email@example.com if you would like to have us blog on a particular topic.