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<\/a><\/p>\nCode:<\/p>\n
\/*Project Title: Double Transducer: Rotational Speed -> Magnetic Field Strength\r\n Team Members: Noel Barnes, Yuqi (Alice) Zhou\r\n Description: Arduino takes in input from a rotary encode to calculate the rotational speed. \r\n This speed is then mapped into a speed that's feed into the DC motor to drive a propeller.\r\n FSR then picks up a force reading from the tilt of the Propeller arm.\r\n The force reading is then mapped to a rotation degree for the servo motor. \r\n Servo motors are moved based on the rotation to move the magentic forward. \r\n Pin mapping:\r\n Arduino pin | role | description\r\n ------------|--------|-------------\r\n A0 input FSR for force sensing\r\n 2 input rotary encoder pin A\r\n 3 input rotary encoder pin B\r\n 5 input drv8833 A2 IN\r\n 6 input drv8833 A1 IN \r\n 10 output servo motor #1\r\n 11 output servo motor #2 \r\n SCL SCL of LCD\r\n SDA SDA of LCD\r\n\r\n Rotoray Encoder Code adapted from https:\/\/dronebotworkshop.com\/rotary-encoders-arduino\/#Arduino_Motor_Encoder_Sketch DroneBot Workshop 2019\r\n DC motor code adapted from https:\/\/courses.ideate.cmu.edu\/16-223\/f2016\/text\/lib\/WheelDrive.html#wheeldrive-doxygen\r\n*\/\r\n\r\n#include <Servo.h>\r\n#include <Wire.h>\r\n#include <LiquidCrystal_I2C.h>\r\n\r\nLiquidCrystal_I2C screen(0x27, 16, 2);\r\n\r\n\/\/ Motor encoder output pulse per rotation (change as required)\r\n#define ENC_COUNT_REV 374\r\n\r\n\/\/ Encoder output to Arduino Interrupt pin\r\n#define ENC_IN 3\r\n\r\n\/\/ Pulse count from encoder\r\nvolatile long encoderValue = 0;\r\n\r\n\/\/ interval for measurements of rotational speed\r\nint interval = 100;\r\nconst int quaterSec = 250;\r\nunsigned long timer = 0;\r\nlong previousMillis = 0;\r\nlong currentMillis = 0;\r\n\r\nint rpm = 0;\r\nint rpmDisplay; \/\/ RPM display for the LCD screen\r\nint motorRPM; \/\/ DC motor speed\r\nint dcDisplay; \/\/ DC motor speed display for LCD screen\r\n\r\n\/\/make a servo object\r\nServo lilMotor;\r\nServo secMotor;\r\nconst int LILMOTORPIN = 11; \/\/ Servo Motor to pin 11\r\nconst int SECMOTORPIN = 10; \/\/ Servo Motor to pin 10\r\n\r\nint force; \/\/ the analog reading from the FSR \r\nint forceDisplay; \/\/ force display for the LDC screen\r\nint fsrPin = 0; \/\/ the FSR and 10K pulldown are connected to a0\r\n\r\nint rotation; \/\/ rotation degree for lilMotor\r\nint rotationTwo; \/\/ rotation degree for secMotor\r\nint rotationDisplay; \/\/ servo motor rotation display for LDC screen\r\n\r\n#define A1PIN 6\r\n#define A2PIN 5\r\n\r\nvoid setup() {\r\n \/\/ Set encoder as input with internal pullup\r\n pinMode(ENC_IN, INPUT_PULLUP);\r\n \/\/ Attach interrupt\r\n attachInterrupt(digitalPinToInterrupt(ENC_IN), updateEncoder, RISING);\r\n \/\/ Setup initial values for timer\r\n previousMillis = millis();\r\n\r\n \/\/ initialize DC motor\r\n pinMode(A1PIN, OUTPUT);\r\n pinMode(A2PIN, OUTPUT);\r\n digitalWrite(A1PIN, LOW);\r\n digitalWrite(A2PIN, LOW);\r\n\r\n \/\/ tell Arduino where the servo motors are plugged in\r\n lilMotor.attach(LILMOTORPIN);\r\n secMotor.attach(SECMOTORPIN);\r\n \/\/ initialize the screen (only need to do this once)\r\n screen.init();\r\n \/\/ turn on the backlight to start\r\n screen.backlight();\r\n\r\n \/\/ lcd display template\r\n screen.home();\r\n screen.print(\"i:\");\r\n screen.setCursor(6, 0);\r\n screen.print(\"m:\");\r\n screen.setCursor(12, 1);\r\n screen.print(\"o:\");\r\n\r\n}\r\n\r\nvoid loop() {\r\n \/\/ Update RPM value\r\n currentMillis = millis();\r\n if (currentMillis - previousMillis > interval) {\r\n previousMillis = currentMillis;\r\n \/\/ Calculate RPM\r\n rpm = (float)(encoderValue * 60 \/ ENC_COUNT_REV);\r\n \/\/follow the range of 20-60 for rotational speed\r\n if (rpm > 60) {\r\n rpm = 60;\r\n }\r\n if (rpm < 20) {\r\n rpm = 20;\r\n }\r\n encoderValue = 0;\r\n }\r\n \/\/rotational speed display\r\n if (millis() - timer >= quaterSec) {\r\n screen.setCursor(2, 0);\r\n rpmDisplay = map(rpm, 20, 60, 0, 99);\r\n screen.print(rpmDisplay);\r\n }\r\n\r\n \/\/ run DC motor with RPM \r\n motorRPM = map(rpm, 20 , 60, 80, 255); \/\/normalize rotational speed to input as DC motor speed\r\n digitalWrite(A1PIN, LOW);\r\n analogWrite(A2PIN, motorRPM);\r\n delay(2);\r\n \r\n \/\/ DC motor speed display\r\n if (millis() - timer >= quaterSec) {\r\n screen.setCursor(8, 0);\r\n dcDisplay = map(motorRPM, 80, 255, 0, 99); \/\/ normalized for display\r\n screen.print(dcDisplay);\r\n }\r\n\r\n\r\n \/\/ force reading\r\n force = analogRead(fsrPin);\r\n \/\/ limit to a force range that's appropriate for the propeller arm setup\r\n if (force > 400) {\r\n force = 400;\r\n }\r\n if (force < 50) {\r\n force = 50;\r\n }\r\n \r\n \/\/ force sensor display\r\n if (millis() - timer >= quaterSec) {\r\n forceDisplay = map(force, 50, 400, 0, 99); \/\/ normalized force for display\r\n screen.setCursor(8, 1);\r\n screen.print(forceDisplay);\r\n }\r\n\r\n \/\/ calculate rotation for the two servo motors\r\n rotation = map(force, 50, 400, 10, 170); \/\/ map force reading to motor rotation degree\r\n rotationTwo = 180 - rotation;\r\n \r\n \/\/ servo motor rotation degree display\r\n if (millis() - timer >= quaterSec) {\r\n rotationDisplay = map(rotation, 10, 170, 0, 99); \/\/ normalized rotation degree for display\r\n screen.setCursor(14, 1);\r\n screen.print(rotationDisplay);\r\n timer = millis();\r\n }\r\n\r\n \/\/ rotate the servo motors\r\n lilMotor.write(rotation);\r\n secMotor.write(rotationTwo);\r\n\r\n}\r\n\r\nvoid updateEncoder()\r\n{\r\n \/\/ Increment value for each pulse from encoder\r\n encoderValue++;\r\n}<\/pre>\n <\/p>\n","protected":false},"excerpt":{"rendered":"
Alice’s Board Video of working machine: when rotational speed is at its highest, the propeller spins fast and presses down on the force sensor a lot, which translates…<\/p>\n","protected":false},"author":198,"featured_media":13985,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[86],"tags":[],"_links":{"self":[{"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/posts\/13932"}],"collection":[{"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/users\/198"}],"replies":[{"embeddable":true,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/comments?post=13932"}],"version-history":[{"count":16,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/posts\/13932\/revisions"}],"predecessor-version":[{"id":14104,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/posts\/13932\/revisions\/14104"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/media\/13985"}],"wp:attachment":[{"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/media?parent=13932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/categories?post=13932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/courses.ideate.cmu.edu\/60-223\/f2021\/work\/wp-json\/wp\/v2\/tags?post=13932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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