Formula & Units vs FlightPlan!

Formula & Units is an ultimate tool for calculation of complex scientific expressions and convertion of scientific units. Expressions may be comprised of variables and constants, possessing numeric values and sets of units. Support and info at www.volard.wordpress.com The application interface consists of three custom (A, B, C) value-units expressions and six preset constants, which may be added to the final expression field by pressing the corresponding buttons. Value-Units Expression contains three fields: value field, numerator (top) units field and denominator (bottom) units field. Units must be typed exactly as they appear in the provided list in the Help section. Power of unit is typed directly after unit : s2. Metric prefixes or unit prefixes are recognized automatically: mm = 1.0e-3 m, kA = 1000 A. Metric prefix micro- (1e-6), is changed to 'u'. Additional Units can be added upon request through www.volard.wordpress.com. Example of unit expression as it should appear in numerator or denominator fields: mm2*s*kg*uA-2*MPa-2. Upon addition or subtraction, unit expressions should be of the same dimensionality! Meters cannot be added to Pascals!!! Application provides set of widely used physico-chemical constants. Pressing the corresponding constant button adds the value to the final field. Presets are: Na - Avogadro's constant, h - Planck constant, F - Faraday constant, R - gas constant, kB - Boltzmann constant, g - acceleration of gravity, e - elementary charge, Pi - pi constant. (All in SI units) The final expression is a regular scientific formula consisting of value-units expressions, regular math operations, numbers and functions. Available math functions are provided with buttons-shortcuts. Dot is used as a decimal point. Pressing "Calculate" button evaluates final expression. By default, application converts all units to International System of Units (SI), but it is possible to set the required units directly to the final (where result is shown) units fields before calculation, then the result will be adjusted to meet the requirement. The resulting final expression can be copied to A expression field, by pressing a "A^" top bar button, for further conversion or calculations. For a simple conversion, type the expression that should be converted to A field and preferred units to the B field. Special attention should be paid to dimensionality! For example: To change m3 to US Gallon in expression s*kg/m3, type gal-1 to numerator field or gal to denominator field in the B expression. Press 'convert' button to get the final converted result. For conversion numeric value of B expression has no meaning. Examples can be found at www.volard.wordpress.com.

This app allows you to visually program a flight plan for the Tello Drone and then upload it to the drone for execution. You can also fly the drone manually with the app if you wish. Real time telemetry from the drone is displayed on the glass cockpit. Tello is a mini drone equipped with a HD camera that is manufactured by Ryze Robotics and includes a flight controller with DJI smarts. We access the Tello API by connecting to the airframe via a WiFi UDP port. Once a connection is in place, the drone is controlled using simple text commands. So before using the app, make sure that your Tello drone is on and the iPhone is connected to the Tello WiFi. You can check this by going to Settings -> WiFi. The first time that you use the app it will request your permission to use Location Services. This is required to allow the app to determine the SSID of the WiFi connection so we know when you are connected to the drone. The app doesn't use location services for anything else. The app has two modes of operation: manual and planning / auto pilot. The app status is shown in the top centre panel. This panel also indicates whether WiFi is connected or not. It may take a few seconds for a change in WiFi status to be displayed.  If you are connected to the Tello and in manual mode, then tapping the take off icon will cause the drone to auto take off and hover. Tapping land will auto land. Only tap emergency stop if necessary as it will immediately stop all four motors and the drone will fall out of the sky! Tapping the plan button toggles the app state between planning mode and manual mode. In planning mode a grid (representing the ground) and yellow arrow (representing the drone), will appear. The arrow direction indicates the front of the drone. In planning mode, you can enter the sequence of commands which will be transmitted to your drone for execution. Start with take off or you will receive a warning message. When you are finished with your flight plan tap land. The arrow will simulate the position of the drone but is not to scale. Tapping the upload icon will send your flight plan to the Tello and execute it. While the plan is being flown, the app will display the glass cockpit. Real time telemetry from the drone is displayed on the glass cockpit. This includes pitch, roll, yaw, velocity (x, y, z), temperature, time of flight (tof), height, battery percentage, motor on time, barometric pressure, and acceleration (x, y, z). A full description of how the app operates is provided at our website (reefwing.com.au). FlightPlan is a refined version of another that I described in an article called "Programming the Tello Drone using Swift." (https://medium.com/@reefwing/programming-the-tello-drone-using-swift-f9122fd4aeb8?). You can refer to this article to understand how the app operates and create your own version.