Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Last revision Both sides next revision
fabricademy2017:students:nuria.robles:week_9 [2018/02/15 23:40]
nuriafablab_gmail.com
fabricademy2017:students:nuria.robles:week_9 [2018/05/12 00:21]
nuriafablab_gmail.com
Line 18: Line 18:
  
 Create an interactive object; if you are already experienced with coding, focus on fully integrating a microcontoller into a textile circuit. If you are new to coding, choose an example and get it working using your own sensors and actuators. Create an interactive object; if you are already experienced with coding, focus on fully integrating a microcontoller into a textile circuit. If you are new to coding, choose an example and get it working using your own sensors and actuators.
 +
 +----
 +
 +=== Digital Sensor Circuits ===
 +
 +A **digital sensor** ​ is an electronic or electrochemical sensor, where [[https://​en.wikipedia.org/​wiki/​Data_conversion|data conversion]] and data transmission are done digitally.
 +
 +When a digital sensor is connected to a microcontroller,​ need to use a pull down or pull-up resistor. A nice tutorial about pull-up, pull-down resistor can be found [[https://​learn.sparkfun.com/​tutorials/​pull-up-resistors|here]].
 +
 +=== Reading Resistive Sensors ===
 +
 +The first thing I want to test is how my crochet pressure sensor acts in a voltage divider. Many sensors in the real world are simple resistive devices. A [[https://​www.sparkfun.com/​products/​9088|photocell]] is a variable resistor, which produces a resistance proportional to the amount of light it senses. Other devices like [[https://​www.sparkfun.com/​products/​8606?​|flex sensors]], [[https://​www.sparkfun.com/​products/​9375|force-sensitive resistors]],​ and [[https://​www.sparkfun.com/​products/​250|thermistors]],​ are also variable resistors.
 +
 +It turns out voltage is really easy for microcontrollers (those with [[https://​learn.sparkfun.com/​tutorials/​analog-to-digital-conversion|analog-to-digital converters]] - ADC’s - at least) to measure. Resistance? Not so much. But, by adding another resistor to the resistive sensors, we can create a voltage divider. Once the output of the voltage divider is known, we can go back and calculate the resistance of the sensor.
 +
 +For example, the photocell’s resistance varies between 1kΩ in the light and about 10kΩ in the dark. If we combine that with a static resistance somewhere in the middle - say 5.6kΩ, we can get a wide range out of the voltage divider they create.
  
 ---- ----
Line 39: Line 55:
 {{  :​fabricademy2017:​students:​nuria.robles:​week9_etextile_wearablesii:​lilypad_arduino_processing.png?​nolink&​600x613 ​ }} {{  :​fabricademy2017:​students:​nuria.robles:​week9_etextile_wearablesii:​lilypad_arduino_processing.png?​nolink&​600x613 ​ }}
  
-A video of the circuit working can be watched here:+Here is te arduino code :
  
-{{vimeo>255993043?​large}}+<code> 
 +#define OUTPUT_TEAPOT
  
-===   ===+#define INTERRUPT_PIN 2  // use pin 2 on Arduino Uno & most boards 
 +#define LED_PIN 13 // (Arduino is 13, Teensy is 11, Teensy++ is 6) 
 +bool blinkState ​false;
  
-=== Digital Sensor Circuits ===+// MPU control/​status vars 
 +bool dmpReady ​false; ​ // set true if DMP init was successful 
 +uint8_t mpuIntStatus; ​  // holds actual interrupt status byte from MPU 
 +uint8_t devStatus; ​     // return status after each device operation (0 success, !0 error) 
 +uint16_t packetSize; ​   // expected DMP packet size (default is 42 bytes) 
 +uint16_t fifoCount; ​    // count of all bytes currently in FIFO 
 +uint8_t fifoBuffer[64];​ // FIFO storage buffer
  
-A **digital ​sensor**  is an electronic or electrochemical ​sensor, ​where [[https://en.wikipedia.org/wiki/Data_conversion|data conversion]] and data transmission are done digitally.+// orientation/​motion vars 
 +Quaternion q;           // [w, x, y, z]         ​quaternion container 
 +VectorInt16 aa;         // [x, y, z]            accel sensor ​measurements 
 +VectorInt16 aaReal; ​    // [x, y, z]            gravity-free accel sensor ​measurements 
 +VectorInt16 aaWorld; ​   // [xy, z]            world-frame accel sensor measurements 
 +VectorFloat gravity; ​   // [x, y, z]            gravity vector 
 +float euler[3];         // [psi, theta, phi]    Euler angle container 
 +float ypr[3]; ​          // [yaw, pitch, roll  yaw/​pitch/​roll container ​and gravity vector
  
-When a digital sensor is connected to a microcontroller,​ need to use a pull down or pull-up resistor. A nice tutorial about pull-up, pull-down resistor can be found [[https://learn.sparkfun.com/​tutorials/​pull-up-resistors|here]].+// packet structure for InvenSense teapot demo 
 +uint8_t teapotPacket[14= { '​$',​ 0x02, 0,0, 0,0, 0,0, 0,0, 0x00, 0x00, '​r',​ '​n'​ };
  
-=== Reading Resistive Sensors ​===+// ================================================================ 
 +// ===               ​INTERRUPT DETECTION ROUTINE ​               === 
 +// ================================================================
  
-The first thing I want to test is how my crochet pressure sensor acts in a voltage divider. Many sensors in the real world are simple resistive devices. A [[https://www.sparkfun.com/​products/​9088|photocell]] is a variable resistor, which produces a resistance proportional to the amount of light it senses. Other devices like [[https://​www.sparkfun.com/​products/​8606?​|flex sensors]], [[https://​www.sparkfun.com/​products/​9375|force-sensitive resistors]],​ and [[https://​www.sparkfun.com/​products/​250|thermistors]],​ are also variable resistors.+volatile bool mpuInterrupt = false; ​    // indicates whether MPU interrupt pin has gone high 
 +void dmpDataReady() { 
 +    mpuInterrupt = true; 
 +}
  
-It turns out voltage is really easy for microcontrollers (those with [[https://learn.sparkfun.com/tutorials/analog-to-digital-conversion|analog-to-digital converters]] - ADC’s - at least) to measure. Resistance? Not so much. But, by adding another resistor to the resistive sensors, we can create a voltage divider. Once the output of the voltage divider is known, we can go back and calculate the resistance of the sensor.+// ================================================================ 
 +// ===                      INITIAL SETUP                       === 
 +// ================================================================
  
-For examplethe photocell’resistance varies between 1kΩ in the light and about 10kΩ in the darkIf we combine that with static resistance somewhere ​in the middle ​say 5.6kΩwe can get a wide range out of the voltage divider they create.+void setup() { 
 +    // join I2C bus (I2Cdev library doesn'​t do this automatically) 
 +    #if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE 
 +        Wire.begin();​ 
 +        Wire.setClock(400000);​ // 400kHz I2C clock. Comment this line if having compilation difficulties 
 +    #elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE 
 +        Fastwire::​setup(400true); 
 +    #endif 
 + 
 +    // initialize serial communication 
 +    // (115200 chosen because it is required for Teapot Demo output, but it's 
 +    // really up to you depending on your project) 
 +    Serial.begin(115200);​ 
 +    while (!Serial); // wait for Leonardo enumeration,​ others continue immediately 
 + 
 +    // NOTE: 8MHz or slower host processors, like the Teensy @ 3.3V or Arduino 
 +    // Pro Mini running at 3.3V, cannot handle this baud rate reliably due to 
 +    // the baud timing being too misaligned with processor ticks. You must use 
 +    // 38400 or slower ​in these cases, or use some kind of external separate 
 +    // crystal solution for the UART timer. 
 + 
 +    // initialize device 
 +    Serial.println(F("​Initializing I2C devices..."​));​ 
 +    mpu.initialize();​ 
 +    pinMode(INTERRUPT_PIN,​ INPUT); 
 + 
 +    // verify connection 
 +    Serial.println(F("​Testing device connections..."​));​ 
 +    Serial.println(mpu.testConnection() ? F("​MPU6050 connection successful"​) : F("​MPU6050 connection failed"​));​ 
 + 
 +    // wait for ready 
 +    Serial.println(F("​nSend any character to begin DMP programming ​and demo: ")); 
 +    while (Serial.available() && Serial.read());​ // empty buffer 
 +    while (!Serial.available()); ​                // wait for data 
 +    while (Serial.available() && Serial.read());​ // empty buffer again 
 + 
 +    // load and configure the DMP 
 +    Serial.println(F("​Initializing DMP..."​));​ 
 +    devStatus = mpu.dmpInitialize();​ 
 + 
 +    // supply your own gyro offsets here, scaled for min sensitivity 
 +    mpu.setXGyroOffset(220);​ 
 +    mpu.setYGyroOffset(76);​ 
 +    mpu.setZGyroOffset(-85);​ 
 +    mpu.setZAccelOffset(1788);​ // 1688 factory default for my test chip 
 + 
 +    // make sure it worked (returns 0 if so) 
 +    if (devStatus == 0) { 
 +        // turn on the DMP, now that it's ready 
 +        Serial.println(F("​Enabling DMP..."​));​ 
 +        mpu.setDMPEnabled(true);​ 
 + 
 +        // enable Arduino interrupt detection 
 +        Serial.println(F("​Enabling interrupt detection (Arduino external interrupt 0)..."​));​ 
 +        attachInterrupt(digitalPinToInterrupt(INTERRUPT_PIN),​ dmpDataReady,​ RISING); 
 +        mpuIntStatus = mpu.getIntStatus();​ 
 + 
 +        // set our DMP Ready flag so the main loop() function knows it's okay to use it 
 +        Serial.println(F("​DMP ready! Waiting for first interrupt..."​));​ 
 +        dmpReady = true; 
 + 
 +        // get expected DMP packet size for later comparison 
 +        packetSize = mpu.dmpGetFIFOPacketSize();​ 
 +    } else { 
 +        // ERROR! 
 +        // 1 = initial memory load failed 
 +        // 2 = DMP configuration updates failed 
 +        // (if it's going to break, usually the code will be 1) 
 +        Serial.print(F("​DMP Initialization failed (code ")); 
 +        Serial.print(devStatus);​ 
 +        Serial.println(F("​)"​));​ 
 +    } 
 + 
 +    // configure LED for output 
 +    pinMode(LED_PIN,​ OUTPUT); 
 +
 + 
 +// ================================================================ 
 +// ===                    MAIN PROGRAM LOOP                     === 
 +// ================================================================ 
 + 
 +void loop() { 
 +    // if programming failed, don't try to do anything 
 +    if (!dmpReady) return; 
 + 
 +    // wait for MPU interrupt or extra packet(s) available 
 +    while (!mpuInterrupt && fifoCount <​packetSize) { 
 +        // other program behavior stuff here 
 +        // . 
 +        // . 
 +        // . 
 +        // if you are really paranoid you can frequently test in between other 
 +        // stuff to see if mpuInterrupt is true, and if so, "​break;"​ from the 
 +        // while() loop to immediately process the MPU data 
 +        // . 
 +        // . 
 +        // . 
 +    } 
 + 
 +    // reset interrupt flag and get INT_STATUS byte 
 +    mpuInterrupt = false; 
 +    mpuIntStatus = mpu.getIntStatus();​ 
 + 
 +    // get current FIFO count 
 +    fifoCount = mpu.getFIFOCount();​ 
 + 
 +    // check for overflow (this should never happen unless our code is too inefficient) 
 +    if ((mpuIntStatus & 0x10) || fifoCount == 1024) { 
 +        // reset so we can continue cleanly 
 +        mpu.resetFIFO();​ 
 +        Serial.println(F("​FIFO overflow!"​));​ 
 + 
 +    // otherwise, check for DMP data ready interrupt (this should happen frequently) 
 +    } else if (mpuIntStatus & 0x02) { 
 +        // wait for correct available data length, should be VERY short wait 
 +        while (fifoCount <​packetSize) fifoCount = mpu.getFIFOCount();​ 
 + 
 +        // read a packet from FIFO 
 +        mpu.getFIFOBytes(fifoBuffer,​ packetSize);​ 
 + 
 +        // track FIFO count here in case there is> 1 packet available 
 +        // (this lets us immediately read more without waiting for an interrupt) 
 +        fifoCount ​-= packetSize;​ 
 + 
 +        #ifdef OUTPUT_READABLE_QUATERNION 
 +            // display quaternion values in easy matrix form: w x y z 
 +            mpu.dmpGetQuaternion(&​q,​ fifoBuffer);​ 
 +            Serial.print("​quat\t"​);​ 
 +            Serial.print(q.w);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(q.x);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(q.y);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.println(q.z);​ 
 +        #endif 
 + 
 +        #ifdef OUTPUT_READABLE_EULER 
 +            // display Euler angles in degrees 
 +            mpu.dmpGetQuaternion(&​q,​ fifoBuffer);​ 
 +            mpu.dmpGetEuler(euler,​ &q); 
 +            Serial.print("​euler\t"​);​ 
 +            Serial.print(euler[0] * 180/​M_PI);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(euler[1] * 180/​M_PI);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.println(euler[2] * 180/​M_PI);​ 
 +        #endif 
 + 
 +        #ifdef OUTPUT_READABLE_YAWPITCHROLL 
 +            // display Euler angles in degrees 
 +            mpu.dmpGetQuaternion(&​q,​ fifoBuffer);​ 
 +            mpu.dmpGetGravity(&​gravity,​ &q); 
 +            mpu.dmpGetYawPitchRoll(ypr,​ &q, &​gravity);​ 
 +            Serial.print("​ypr\t"​);​ 
 +            Serial.print(ypr[0] * 180/​M_PI);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(ypr[1] * 180/​M_PI);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.println(ypr[2] * 180/​M_PI);​ 
 +        #endif 
 + 
 +        #ifdef OUTPUT_READABLE_REALACCEL 
 +            // display real acceleration,​ adjusted to remove gravity 
 +            mpu.dmpGetQuaternion(&​q,​ fifoBuffer);​ 
 +            mpu.dmpGetAccel(&​aa,​ fifoBuffer);​ 
 +            mpu.dmpGetGravity(&​gravity,​ &q); 
 +            mpu.dmpGetLinearAccel(&​aaReal,​ &aa, &​gravity);​ 
 +            Serial.print("​areal\t"​);​ 
 +            Serial.print(aaReal.x);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(aaReal.y);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.println(aaReal.z);​ 
 +        #endif 
 + 
 +        #ifdef OUTPUT_READABLE_WORLDACCEL 
 +            // display initial world-frame acceleration,​ adjusted to remove gravity 
 +            // and rotated based on known orientation from quaternion 
 +            mpu.dmpGetQuaternion(&​q,​ fifoBuffer);​ 
 +            mpu.dmpGetAccel(&​aa,​ fifoBuffer);​ 
 +            mpu.dmpGetGravity(&​gravity,​ &q); 
 +            mpu.dmpGetLinearAccel(&​aaReal,​ &aa, &​gravity);​ 
 +            mpu.dmpGetLinearAccelInWorld(&​aaWorld,​ &​aaReal,​ &q); 
 +            Serial.print("​aworld\t"​);​ 
 +            Serial.print(aaWorld.x);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.print(aaWorld.y);​ 
 +            Serial.print("​\t"​);​ 
 +            Serial.println(aaWorld.z);​ 
 +        #endif 
 + 
 +        #ifdef OUTPUT_TEAPOT 
 +            // display quaternion values in InvenSense Teapot demo format: 
 +            teapotPacket[2] = fifoBuffer[0];​ 
 +            teapotPacket[3] = fifoBuffer[1];​ 
 +            teapotPacket[4] = fifoBuffer[4];​ 
 +            teapotPacket[5] = fifoBuffer[5];​ 
 +            teapotPacket[6] = fifoBuffer[8];​ 
 +            teapotPacket[7] = fifoBuffer[9];​ 
 +            teapotPacket[8] = fifoBuffer[12];​ 
 +            teapotPacket[9] = fifoBuffer[13];​ 
 +            Serial.write(teapotPacket14); 
 +            teapotPacket[11]++;​ // packetCount,​ loops at 0xFF on purpose 
 +        #endif 
 + 
 +        // blink LED to indicate activity 
 +        blinkState = !blinkState;​ 
 +        digitalWrite(LED_PIN,​ blinkState);​ 
 +    } 
 +
 +</​code>​ 
 + 
 +A video of the circuit working can be watched here: 
 + 
 +{{vimeo>​255993043?​large}} 
 + 
 +===   === 
 + 
 +===   ===