fabricademy2017:students:nuria.robles:week_9 [Textile Academy]

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--- fabricademy2017:students:nuria.robles:week_9 [2018/02/15 23:39]
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.
+----
+=== 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.
 ----
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 {{  :fabricademy2017:students:nuria.robles:week9_etextile_wearablesii:acelerometro_lilypad_coser.png?nolink&600x613  }}
-===     :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;    // [x, y, 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 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.
+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(400, true);
+    #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 a 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(teapotPacket, 14);
+            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}}
+===   ===
+===   ===