TpSol --oOo-- Version 1.1		DesCad --oOo-- Version 1.0
	Yvon Massé yvon.massesfr.fr

TpSol and DesCad are two applications for Android version 4.0 or higher. They share to draw the sundial corresponding to the orientation of the smartphone or the tablet. So for example, like on the picture, it is possible to apply the device on a wall to get the drawing of the corresponding sundial. The shadow is also drawn, this allows you to learn the gnomonics in a playful manner.

To know the device orientation, these applications use the magnetic sensor that it is necessary to calibrate following the procedure described below.

TpSol

The main function of TpSol is to give the solar time according to the date, the legal time and the GPS location. These parameters can be input manually. Moreover, TpSol gives:

• the equation of time and the solar declination,
• the azimuth and the altitude of the Sun.

TpSol is free, download it on Google-Play

DesCad

At launching, DesCad displays directly the sundial: the setup is automatic. It is then possible to modify the parameters to explore all the configurations. The following parameters are especially modifiable:

• geographical location,
• date and time of the shadow,
• orientation of the dial,
• position and size of the style,
• dimensions of the real sundial (the quantified data allow you to materialize it),
• type of hours (solar or legal hours),
• type of diurnal arcs,
• type of shadow-caster.

The position / size of the style and the date / time of the shadow can be modified by gestures on the touchscreen.

The menu also allows you:

• to store / load the configurations,
• to load specific configurations (horizontal sundial, meridional, occidental, oriental, septentrional, equatorial and polar),
• to access to the help on line.

DesCad has therefore a great educational value for those who are interesting in sundial, from beginner to expert in gnomonics.

DesCad is a cheap application (around 2 $), download it on Google-Play

Calibration of the magnetic sensor

Perform the calibration on the following way:

• be sure that no metallic object or magnet is in the surrounding of the device (think to the magnetic lock of the protection cover)
• activate the dynamic drawing of the sundial by the button Auto / Stop of the group Towards
• orient the smartphone or the tablet towards all the directions. For this:
• stand up and hold the device with the screen facing upwards,
• rotate the device until it faces downwards then a new time upwards,
• repeat the previous step up to the end of the calibration with a regular and alternate movement of around 2 seconds,
• in the same time, turn slowly on yourself during around 30 seconds to complete at least one rotation.

The calibration is finish. The parameters of the sundial orientation (inclination and declination), which are computed and supplied by the application, are then less erratic and more accurate. However, the accuracy is not better than some degrees.

Despite all the care taken to verify these applications, it is possible that some bugs have escaped my attention. If you find any malfunction, do not hesitate to let me know: I shall endeavor to make the necessary changes. I will also be very attentive to proposals from users for improving the program if they express a particular need (yvon.massesfr.fr).

Have a good use!...