499 lines
14 KiB
C++
499 lines
14 KiB
C++
#include <Arduino.h>
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#include <lcdgfx.h>
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#include <FastTrig.h>
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#include "I2Cdev.h"
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// #include "MPU6050_6Axis_MotionApps20.h"
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#include "MPU6050_6Axis_MotionApps612.h"
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// comment out to disable debug output / serial / led
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#define DEBUG
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// LED for debugging interrupts
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#define LED 17
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// sleep params
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#define SLEEP_AFTER_MS 10000
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// External interrupt source
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#define EXT0_PIN 34
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// Simulation constants
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#define SIM_WIDTH 128
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#define SIM_HEIGHT 64
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#define NUM_PARTICLES 250
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#define PARTICLE_RADIUS 2
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#define GRAVITY 1.0f
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#define DAMPING 0.3f
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#define PRESSURE_RADIUS 3.5f
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#define PRESSURE_FORCE 0.9f
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#define MAX_VEL 2.0f
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#define GRID_SIZE 16
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#define CELL_SIZE (SIM_WIDTH/GRID_SIZE)
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/**
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* Class implements SSD1306 128x64 lcd display in 1 bit mode over I2C
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* overrides default implementation to expose private m_i2c
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*/
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class DisplaySSD1306_128x64_I2Cx: public DisplaySSD1306_128x64<InterfaceSSD1306<PlatformI2c>>
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{
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public:
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/**
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* @brief Inits 128x64 lcd display over i2c (based on SSD1306 controller): 1-bit mode.
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*
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* Inits 128x64 lcd display over i2c (based on SSD1306 controller): 1-bit mode
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* @param rstPin pin controlling LCD reset (-1 if not used)
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* @param config platform i2c configuration. Please refer to SPlatformI2cConfig.
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*/
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explicit DisplaySSD1306_128x64_I2Cx(int8_t rstPin, const SPlatformI2cConfig &config = {-1, 0x3C, -1, -1, 0})
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: DisplaySSD1306_128x64(m_i2c, rstPin)
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, m_i2c(*this, -1,
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SPlatformI2cConfig{config.busId, static_cast<uint8_t>(config.addr ?: 0x3C), config.scl, config.sda,
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config.frequency ?: 400000})
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{
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}
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/**
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* Initializes SSD1306 lcd in 1-bit mode
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*/
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void begin() override;
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/**
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* Closes connection to display
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*/
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void end() override;
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InterfaceSSD1306<PlatformI2c> m_i2c;
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};
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void DisplaySSD1306_128x64_I2Cx::begin()
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{
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m_i2c.begin();
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DisplaySSD1306_128x64::begin();
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}
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void DisplaySSD1306_128x64_I2Cx::end()
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{
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DisplaySSD1306_128x64::end();
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m_i2c.end();
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}
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DisplaySSD1306_128x64_I2Cx display(-1);
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MPU6050 mpu;
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// I2C device found at address 0x3C ! // OLED
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// I2C device found at address 0x68 ! // IMU
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typedef float f32 __attribute__((aligned(4)));
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struct Particle {
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f32 x, y;
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f32 vx, vy;
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};
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inline float fast_sqrt(float x) {
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union { float f; uint32_t i; } u;
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u.f = x;
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u.i = 0x5f375a86 - (u.i >> 1);
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return u.f * (1.5f - 0.5f * x * u.f * u.f);
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}
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Particle particles[NUM_PARTICLES];
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uint8_t canvasData[SIM_WIDTH*(SIM_HEIGHT/8)]; // because of 1bit display, not RGB
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NanoCanvas1 canvas(SIM_WIDTH, SIM_HEIGHT, canvasData);
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/*---Sleep/wake vars---*/
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uint32_t lastZMot = 0;
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bool zMotInterrupt = false;
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/*---MPU6050 Control/Status Variables---*/
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bool DMPReady = false; // Set true if DMP init was successful
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uint8_t MPUIntStatus; // Holds actual interrupt status byte from MPU
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uint8_t devStatus; // Return status after each device operation (0 = success, !0 = error)
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uint16_t packetSize; // Expected DMP packet size (default is 42 bytes)
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uint8_t FIFOBuffer[64]; // FIFO storage buffer
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/*---Orientation/Motion Variables---*/
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Quaternion q; // [w, x, y, z] Quaternion container
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VectorInt16 aa; // [x, y, z] Accel sensor measurements
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VectorInt16 gy; // [x, y, z] Gyro sensor measurements
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VectorFloat gravity; // [x, y, z] Gravity vector
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uint16_t fifoCount;
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/*------Interrupt detection routine------*/
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volatile bool MPUInterrupt = true; // Indicates whether MPU6050 interrupt pin has gone high
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void DMPDataReady() {
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MPUInterrupt = true;
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}
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// Setup serial communication
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// only for debugging
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void initSerial() {
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Serial.begin(115200);
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while (!Serial) {
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;
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}
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}
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// Setup I2C communication for IMU
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// would be nice to remove this library
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// requirement and somehow
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// reuse the implementation from the OLED
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void initI2C() {
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Wire.begin();
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Wire.setClock(400000);
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display.m_i2c.displayOn();
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display.m_i2c.setContrast(0);
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}
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void initMpu() {
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zMotInterrupt = false;
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lastZMot = 0;
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// avoid unnecessary resets by checking
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// a non-default value
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if (mpu.getAccelerometerPowerOnDelay() == 2) {
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return;
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}
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mpu.initialize();
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mpu.CalibrateAccel(6); // Calibration Time: generate offsets and calibrate our MPU6050
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mpu.CalibrateGyro(6);
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// time taken for accel to settle after power on
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// i think 4 is the starting and this adds additional wait time
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mpu.setAccelerometerPowerOnDelay(2); //max 3
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mpu.setTempSensorEnabled(false);
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}
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void mpuSetInterruptMode(){
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// set the interrupt to latch until data is read
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// this is nice so on mpu.getIntStatus() it will clear the interrupt
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mpu.setInterruptLatch(MPU6050_INTLATCH_WAITCLEAR);
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mpu.setInterruptLatchClear(MPU6050_INTCLEAR_STATUSREAD);
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// i honeslly don't know what the other versions of this is
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// it's either push-pull or open-drain
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mpu.setInterruptDrive(MPU6050_INTDRV_PUSHPULL);
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}
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/** mpu setup for motion detection
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* this will be used to wake the ESP32
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* from deep sleep (so when ESP is sleeping, accel is in low-ish power mode)
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*/
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void mpuMotionDetectMode() {
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// set up MPU
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// docs recommend waiting for at least 50ms after reset
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mpu.reset();
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lcd_delay(100);
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mpu.resetSensors();
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lcd_delay(100);
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mpu.setTempSensorEnabled(false);
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// disable fifo when sleeping
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mpu.setFIFOEnabled(false);
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// low pass filter, 42Hz
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mpu.setDLPFMode(MPU6050_DLPF_BW_42);
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lcd_delay(10);
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// high pass filter, from current value (should not be done while in motion)
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mpu.setDHPFMode(MPU6050_DHPF_HOLD);
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// mpu.setIntEnabled(0);
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// set interrupt to be high when motion detected
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mpu.setInterruptMode(MPU6050_INTMODE_ACTIVELOW);
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mpu.setClockSource(MPU6050_CLOCK_INTERNAL);
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// lowest accel sens
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mpu.setFullScaleAccelRange(MPU6050_ACCEL_FS_2);
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// lowest gyro sens
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mpu.setFullScaleGyroRange(MPU6050_GYRO_FS_250);
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mpu.setDHPFMode(MPU6050_DHPF_RESET); // reset high-pass filter in prep for hold mode
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// // adjust values from calib script example, if needed
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// mpu.setXGyroOffset(-69);
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// mpu.setYGyroOffset(-48);
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// mpu.setZGyroOffset(-19);
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// mpu.setXAccelOffset(-5158);
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// mpu.setYAccelOffset(-4576);
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// mpu.setZAccelOffset(7687);
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// level of movement required to trigger interrupt
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// recommended default is 20
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mpu.setMotionDetectionThreshold(1);
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// number of milliseconds that the sensor must be at the threshold
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mpu.setMotionDetectionDuration(1);
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// enable only motion detection interrupt
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mpu.setIntEnabled((1 << MPU6050_INTERRUPT_MOT_BIT) | (1 << MPU6050_INTERRUPT_FF_BIT));
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mpu.setAccelerometerPowerOnDelay(2); //max 3
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mpuSetInterruptMode();
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// ensure the accellerometers are on
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// mpu.setStandbyXAccelEnabled(false);
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// mpu.setStandbyYAccelEnabled(false);
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// mpu.setStandbyZAccelEnabled(false);
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// we can sleep the gyro
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mpu.setStandbyXGyroEnabled(true);
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mpu.setStandbyYGyroEnabled(true);
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mpu.setStandbyZGyroEnabled(true);
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mpu.setWakeFrequency(50);
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mpu.setWakeCycleEnabled(true);
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mpu.setSleepEnabled(true);
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}
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/** mpu setup for active monitoring
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* this will be used to monitor the IMU
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* while the ESP32 is awake to run the sim
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*/
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void mpuActiveMonitorMode() {
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// ensure the gyro is on
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mpu.setStandbyXGyroEnabled(false);
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mpu.setStandbyYGyroEnabled(false);
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mpu.setStandbyZGyroEnabled(false);
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devStatus = mpu.dmpInitialize();
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// disable motion detection interrupt
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// and enable data ready interrupt
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// mpu.setIntEnabled(1 << MPU6050_INTERRUPT_DMP_INT_BIT);
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// mpuSetInterruptMode();
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if (devStatus == 0) {
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mpu.CalibrateAccel(6); // Calibration Time: generate offsets and calibrate our MPU6050
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mpu.CalibrateGyro(6);
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mpu.setDMPEnabled(true);
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packetSize = mpu.dmpGetFIFOPacketSize(); // Get expected DMP packet size for later comparison
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mpu.setIntEnabled((1 << MPU6050_INTERRUPT_ZMOT_BIT) | (1 << MPU6050_INTERRUPT_DMP_INT_BIT));
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mpu.setZeroMotionDetectionDuration(2);
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mpu.setZeroMotionDetectionThreshold(20);
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DMPReady = true;
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}
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#ifdef DEBUG
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else {
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Serial.print(F("DMP Initialization failed (code ")); //Print the error code
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Serial.print(devStatus);
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Serial.println(F(")"));
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// 1 = initial memory load failed
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// 2 = DMP configuration updates failed
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}
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#endif
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}
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struct GridCell {
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uint8_t particles[10];
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uint8_t count;
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};
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GridCell grid[GRID_SIZE][GRID_SIZE];
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#ifdef DEBUG
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bool blinkState = true;
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#endif
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void buildSpatialGrid() {
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memset(grid, 0, sizeof(grid));
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for(int i=0; i<NUM_PARTICLES; i++) {
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#ifdef __AVR__
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float x = TO_FLOAT(particles[i].x);
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float y = TO_FLOAT(particles[i].y);
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#else
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float x = particles[i].x;
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float y = particles[i].y;
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#endif
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int gx = constrain(x / CELL_SIZE, 0, GRID_SIZE-1);
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int gy = constrain(y / CELL_SIZE, 0, GRID_SIZE-1);
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if(grid[gx][gy].count < 10) {
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grid[gx][gy].particles[grid[gx][gy].count++] = i;
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}
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}
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}
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void setup() {
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DMPReady = false;
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#ifdef DEBUG
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initSerial();
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#endif
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initI2C();
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initMpu();
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mpuActiveMonitorMode();
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pinMode(EXT0_PIN, INPUT);
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#ifdef DEBUG
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pinMode(LED, OUTPUT);
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digitalWrite(LED, blinkState);
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Serial.print(F("Enabling interrupt detection (Arduino external interrupt "));
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Serial.print(digitalPinToInterrupt(EXT0_PIN));
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Serial.println(F(")..."));
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#endif
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attachInterrupt(digitalPinToInterrupt(EXT0_PIN), DMPDataReady, RISING);
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MPUIntStatus = mpu.getIntStatus();
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// }
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// setup display
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display.begin();
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display.clear();
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canvas.setMode(CANVAS_MODE_TRANSPARENT);
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// Initialize particles in a droplet pattern
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float cx = SIM_WIDTH/2;
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float cy = SIM_HEIGHT/4;
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for(int i=0; i<NUM_PARTICLES; i++) {
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float angle = random(360) * PI / 180.0;
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float radius = random(10);
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particles[i].x = cx + icos(angle) * radius;
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particles[i].y = cy + isin(angle) * radius;
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particles[i].vx = random(-50,50)/25.0; // -2 to +2
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particles[i].vy = random(-25,50)/25.0; // -1 to +2
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}
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}
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void applyPhysics() {
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// Build spatial grid
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buildSpatialGrid();
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// Interactions using grid
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const float PRESSURE_RADIUS_SQ = PRESSURE_RADIUS * PRESSURE_RADIUS;
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for(int i=0; i<NUM_PARTICLES; i++) {
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const int gx = particles[i].x / CELL_SIZE;
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const int gy = particles[i].y / CELL_SIZE;
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// Check 3x3 grid around particle
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for(int dx=-1; dx<=1; dx++) {
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for(int dy=-1; dy<=1; dy++) {
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if(gx+dx < 0 || gx+dx >= GRID_SIZE) continue;
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if(gy+dy < 0 || gy+dy >= GRID_SIZE) continue;
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GridCell &cell = grid[gx+dx][gy+dy];
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for(int c=0; c<cell.count; c++) {
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const int j = cell.particles[c];
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if(j <= i) continue; // Avoid duplicate pairs
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const float dx = particles[j].x - particles[i].x;
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const float dy = particles[j].y - particles[i].y;
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const float dist_sq = dx*dx + dy*dy;
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if(dist_sq < PRESSURE_RADIUS_SQ && dist_sq > 0.01f) {
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const float dist = fast_sqrt(dist_sq) + 0.001f;
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const float force = PRESSURE_FORCE * (1.0f - dist/PRESSURE_RADIUS);
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// Only apply horizontal forces to preserve gravity
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particles[i].vx -= force * dx/dist;
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particles[j].vx += force * dx/dist;
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// Reduce vertical force impact
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particles[i].vy -= force * dy/dist * 0.3f;
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particles[j].vy += force * dy/dist * 0.3f;
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}
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}
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}
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}
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}
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// Gravity and movement
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for(int i=0; i<NUM_PARTICLES; i++) {
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particles[i].vy += gravity.x * GRAVITY; // x / y flipped
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particles[i].vx += gravity.y * GRAVITY;
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particles[i].x += particles[i].vx;
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particles[i].y += particles[i].vy;
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particles[i].vx = constrain(particles[i].vx, -MAX_VEL, MAX_VEL);
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particles[i].vy = constrain(particles[i].vy, -MAX_VEL, MAX_VEL);
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// X-axis
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if(particles[i].x <= 0 || particles[i].x >= SIM_WIDTH-1) {
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particles[i].vx *= -DAMPING;
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particles[i].x = constrain(particles[i].x, 1, SIM_WIDTH-2);
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}
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// Y-axis
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if(particles[i].y <= 0 || particles[i].y >= SIM_HEIGHT-1) {
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particles[i].vy *= -DAMPING;
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particles[i].y = constrain(particles[i].y, 1, SIM_HEIGHT-2);
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}
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}
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}
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// Direct canvas buffer access (replace drawParticles)
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void drawParticles() {
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// Clear canvas by direct memory access
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memset(canvasData, 0, sizeof(canvasData));
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// canvas.clear();
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for(int i=0; i<NUM_PARTICLES; i++) {
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int x = constrain(static_cast<int>(particles[i].x + 0.5f), 0, SIM_WIDTH-1);
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int y = constrain(static_cast<int>(particles[i].y + 0.5f), 0, SIM_HEIGHT-1);
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#if PARTICLE_RADIUS == 1
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canvas.putPixel(x, y);
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#else
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canvas.drawCircle(x,y,PARTICLE_RADIUS-1);
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#endif
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}
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display.drawCanvas(0,0,canvas);
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}
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void reportIMU() {
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if (!DMPReady) return; // Stop the program if DMP programming fails.
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if (!MPUInterrupt) return;
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MPUIntStatus = mpu.getIntStatus();
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#ifdef DEBUG
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Serial.println(MPUIntStatus);
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#endif
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/* Read a packet from FIFO */
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fifoCount = mpu.getFIFOCount();
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// check for overflow (this should never happen unless our code is too inefficient)
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if ((MPUIntStatus & 0x10) || fifoCount == 1024) {
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// reset so we can continue cleanly
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mpu.resetFIFO();
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#ifdef DEBUG
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Serial.println(F("FIFO overflow, reseting FIFO"));
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#endif
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} else if (MPUIntStatus & (1 << MPU6050_INTERRUPT_ZMOT_BIT)) {
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// zero motion interrupt
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// this is used if the device is placed somewhere or stops moving
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// then we initialize the countdown to sleep
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lastZMot = millis();
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zMotInterrupt = true;
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}
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// otherwise, check for DMP data ready interrupt (this should happen frequently)
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else if (MPUIntStatus & 0x02) {
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if (mpu.dmpGetCurrentFIFOPacket(FIFOBuffer)) { // Get the Latest packet
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mpu.dmpGetQuaternion(&q, FIFOBuffer);
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mpu.dmpGetGravity(&gravity, &q); // this is all we care about right now
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}
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}
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#ifdef DEBUG
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// change LED state
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blinkState = !blinkState;
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digitalWrite(LED, blinkState);
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#endif
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// reset interrupt flag
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MPUInterrupt = false;
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}
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void sleepTimer() {
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if (zMotInterrupt && millis() - lastZMot > SLEEP_AFTER_MS) {
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#ifdef DEBUG
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Serial.println(F("Going to sleep"));
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#endif
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display.m_i2c.displayOff();
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// detach interrupt
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detachInterrupt(digitalPinToInterrupt(EXT0_PIN));
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// sleep
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mpuMotionDetectMode();
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// clear any pending interrupts
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mpu.getIntStatus();
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// enable wakeup from ext0
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esp_sleep_enable_ext0_wakeup(GPIO_NUM_34, 0);
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lcd_delay(150);
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esp_deep_sleep_start();
|
|
}
|
|
}
|
|
|
|
void loop() {
|
|
static uint32_t last_frame = 0;
|
|
drawParticles();
|
|
reportIMU();
|
|
if(millis() - last_frame >= 33) {
|
|
sleepTimer();
|
|
last_frame = millis();
|
|
applyPhysics();
|
|
} else {
|
|
lcd_delay(millis() - last_frame);
|
|
}
|
|
}
|