When the x axis servo motor reaches the end of its 0

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When the X-axis servo motor reaches the end of its 0-180° range, it enters inverse mode where it must reset in order to keep moving the solar panel towards the light source. To do this, it reverses at high speed until it reaches the opposite end of its motion, and then flips the solar panel on the Y-axis, effectively returning the solar panel to the position it was in before the reset, but upside-down. At this point, the X-axis can continue rotating until it is aimed at the light source. ?? ??? ??? ? ????? ?ℎ?? 𝑖??????? ?ℎ? ??????𝑖?? ?????𝑖?? 𝑖? ????: ? ??𝑤 = 180 − ? ??? Low-Light Mode The automatic tracking mode includes a low-light mode, which is necessary when the total light sensed by the sensors is too low for reliable operation. To check for low-light conditions, all four light sensor values are added together and compared with a threshold value. The threshold value is ?𝐷𝑅 𝑇?𝑡𝑎? = ?𝐷𝑅 𝑇?? + ?𝐷𝑅 𝐵?𝑡𝑡?? + ?𝐷𝑅 𝑅𝑖?ℎ𝑡 + ?𝐷𝑅 𝐿??𝑡 𝐼? ?𝐷𝑅 𝑇?𝑡𝑎? < 3500 ?ℎ?? ??? ?𝑖?ℎ? ???? 𝑖? ??????? 𝐼? ?𝐷𝑅 𝑇?𝑡𝑎? > 3500 𝐴??????𝑖? ???? 𝑖? ???????
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Smart Tracking Solar Panel Final Project Report Page 11 Both servo motors are sent to 90° and parked, so the solar panel is held horizontally to take advantage of whatever ambient light is available from any direction. The system will keep checking for low-light conditions on each cycle of the main loop until the total LDR reading exceeds the threshold and it returns to normal automatic mode. Reading Input Voltage Levels Voltage levels are displayed for the battery level and the solar panel output on the LCD. The internal Arduino Uno analog-to-digital converters are used on analog pins 4 and 5, which have an input range from 0 to 5V. Since the battery has a normal operating voltage of 12V, the level must be lowered using a voltage- divider network of resistors. Using a 10kΩ and 3.6kΩ resist or, the usable range on this input is 0-18.9V, which allows for a safe margin of error. Similarly, the solar panel has a voltage output of 6 to 9V. The voltage-divider network uses two 10kΩ resistors to allow a usable input range from 0 -10V.A lower margin is required as the solar panel is not expected to exceed 9V output. In the software, both analog inputs are read on each cycle of the main program loop using the AnalogRead function, which reads the input as a value from 0-1023. The map function is used to scale the 0-1023 level back to the actual voltage levels, which are displayed on the LCD screen. Bluetooth Connection The Smart Tracking Solar Panel connects to an Android app using a wireless Bluetooth connection. It uses a standard HC-06 Bluetooth module for connecting the Arduino controller to the Android device. The HC-06 was selected as it takes care of pairing automatically and does not require any AT commands from the Arduino to operate as required. It connects directly to the Arduino serial TX/RX pins and acts as a wired serial UART connection, which greatly simplifies the Arduino coding. The
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  • Fall '18
  • Photovoltaics, Liquid crystal display, voltage regulator, Servomechanism, Battery charger

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