Smartphone & Driver App.
The driver app. can run on only Android phones and Android phones with OS over Lollipop 5.0. The motor driver app. controls a stepper motor through the earphone jack of the smart phone connected to the driver. Since the motor control signal is transmitted through the audio channel of the smartphones, an empty phone is strongly recommended to avoid the interruption of incoming phone calls. In wi-fi environments an iPhone or another phone which TeamViewer is installed on can remotely control the empty phone. Then the empty phone controls the stepper motors.
The motor controllability is dependent on the D/A converter of the audio channel of a smartphone. Since the driver system has been tested only on Samsung Galaxy phones over S6, the controllability of other phones can not be guaranteed.
Since the driver uses the amplified signals of weak signals of an earphone, the driver does not work properly with weak input signals. The media volume should be maintained 70% as the setting of the smartphone is changed as Setting > Sound > Volume > Media whenever the earphone jack is connected to the driver.
Driver App. InstallationThe driver app. is provided as the attached file of the another mail after shipping confirmation mail. There are three kinds of driver apps depending on the resistance and L/R time constant are provided. The corresponding driver app. indicated in the table of Stepper Motor page should be used to control motors properly.
Driver App. L/R Time Constant Resistance Rated Cur. Maximum Speed
Low Power > 3 ms > 3 Ω < 1 A 300 RPM
Med Power 2 ~ 3 ms 2 ~ 3 Ω 1 A 600 RPM
High Power < 1 ms < 1 Ω 1 ~ 2 A 900 RPM
Google Drive is the most useful tool to install the driver app. on a smartphone. After the driver app. is uploaded to Google Drive and downloaded from Google Drive on a smartphone, a change of the setting of the smartphone is requested to install the app. of unknown sources. The setting automatically proceeds when the driver app. is downloaded from Google Drive. As the driver app. is installed and opened, the initial display of the driver app. as the following figure appears.
There are three input items in the initial display of the driver app. The first item is the selection of the step angle. There are two step angles. 0.9° or 1.8° is selected as the step angle. The driver type is selected as half step or full step in the next item. The default value of the step angle and driver type is 1.8° and full step respectively. The ENTER button should be touched to change the default value of the step angle and driver type.
For an exact position control of a geared motor exact gear ratio is required. As example, if the gear ratio is 98.7255 : 1, the gear ratio is represented as 51 / 5035. No input is necessary if there is no gear. The default value is 1/1.
There are three driving modes: Running Mode for speed control, Position Mode for position control and Repetition Mode for back and forth motion.
In each mode, MOTOR DRIVER button is used to return to the initial display of the driver app.
Running ModeIn the display as the following figure, when the value between 1 ~ 900 RPM is entered the input RPM is displayed in the middle of the display and the motor runs at the input RPM speed. The motor speed increases or decreases 30 RPM if + button or - button is touched. The maximum speed is 900 RPM if the step angle 1.8° and the driver type is full step. The maximum, increment and decrement speeds are different depending on the step angle, driver type and gear ratio.
When the STOP button is touched the motor stops. Holding torque is maintained as a constant current flows during the motor stop. CW button and CCW button are used to change the direction of rotation. The direction of rotation is changed when the ENTER button is touched after the motor stopped as the STOP button was touched. The EMERGENCY STOP button stops the motor immediately and cuts the motor current.
The driver app. has a soft start and soft stop functions.
The motor rotates the amount of angle when a certain angle is entered. The direction of rotation is decided according to the selection of the CW button and CCW button. Holding torque is maintained as a constant current flows during the motor stop. The EMERGENCY STOP button stops the motor immediately and cuts the motor current.
As a certain angle is entered the motor rotates the amount of angle back and forth repeatedly. The number of repetitions is displayed in the middle of the display. The initial direction of rotation is decided according to the selection of the CW button and CCW button. After 1/2 complete repetition the motor stops when the STOP button is touched. The EMERGENCY STOP button stops the motor immediately and cuts the motor current.
