Vibration sensor using accelerometer on Hannah

hannah-motiondetect.nut

// Vibration sensor using accelerometer on Hannah

//I2C Addresses
const i2c_ioexp = 0x7C;
const i2c_temp  = 0x98;
const i2c_als   = 0xE8;
const i2c_accel = 0x38;

//----------------------------------------
//-- Configure I2C
//----------------------------------------
hardware.configure(I2C_89);
local i2c = hardware.i2c89;

//----------------------------------------
//-- IO Expander Functions
//----------------------------------------
local function ioexp_read(addr) {
    local result = i2c.read(i2c_ioexp, format("%c", addr), 1);
    if (result == null) {
        server.log("i2c read fail");
        return -1;
    } else return result[0];
}

local function ioexp_write(addr, data) {
    i2c.write(i2c_ioexp, format("%c%c",addr, data));
}

local function ioexp_writebit(addr, bitn, level) {
    // read modify write
    local reg = ioexp_read(addr);
    reg = (level==0)?(reg&~(1<<bitn)) : (reg | (1<<bitn));
    ioexp_write(addr, reg)
}

local function ioexp_modify_write(addr, data, mask) {
   local reg = ioexp_read(addr);
   reg = (reg & ~mask) | (data & mask);
   ioexp_write(addr, reg);
}

local function ioexp_setpin(gpio, level) {
    ioexp_writebit(gpio>=8?0x10:0x11, gpio&7, level?1:0);
}

local function ioexp_setdir(gpio, output) {
    ioexp_writebit(gpio>=8?0x0e:0x0f, gpio&7, output?0:1);
}

local function ioexp_setpullup(gpio, enable) {
    ioexp_writebit(gpio>=8?0x06:0x07, gpio&7, enable);
}

local function ioexp_setirqmask(gpio, enable) {
    ioexp_writebit(gpio>=8?0x12:0x13, gpio&7, enable);
}

local function ioexp_setirqedge(gpio, rising, falling) {
    local addr = 0x17 - (gpio>>2);
    local mask = 0x03 << ((gpio&3)<<1);
    local data = (2*falling + rising) << ((gpio&3)<<1);    
    ioexp_modify_write(addr, data, mask);
}

local function ioexp_clearirq(gpio) {
    ioexp_writebit(gpio>=8?0x18:0x19, gpio&7, 1);
}

local function ioexp_readpin(gpio) {
    return (ioexp_read(gpio>=8?0x10:0x11)&(1<<(gpio&7)))?1:0;
}

local function ioexp_setled(gpio, led) {
    ioexp_writebit(gpio>=8?0x20:0x21, gpio&7, led);
}

local function ioexp_update_leds(r,g,b) {
    ioexp_write(0x3b, g);
    ioexp_write(0x40, b);
    ioexp_write(0x45, r);
}

//LED Driver Enable
ioexp_modify_write(0x01, 0xE0, 0xFF);
ioexp_modify_write(0x0f, 0xE0, 0x00);
ioexp_modify_write(0x0b, 0xE0, 0xFF);
ioexp_modify_write(0x21, 0xE0, 0xFF);
ioexp_write(0x1e, 0x50);
ioexp_write(0x1f, 0x10);
ioexp_update_leds(0,0,0);
ioexp_setpin(5, 0);
ioexp_setpin(6, 0);
ioexp_setpin(7, 0);

// Enable Potentiometer
ioexp_setpin(8, 0);
ioexp_setdir(8, 1);
hardware.pin2.configure(ANALOG_IN);

// Enable accelerometer
local e = i2c.write(i2c_accel, "\x20\x47");

local out = OutputPort("Acceleration", "number")

local averageX = 0
local averageY = 0
local averageZ = 0

local warmup = 0

local exponentialFactor = 0.9

function poll() {
    imp.wakeup(0.05, poll)
    
    local accel = i2c.read(i2c_accel, "\x29", 1) + i2c.read(i2c_accel, "\x2B", 1) + i2c.read(i2c_accel, "\x2D", 1)
    
    local x = ((accel[0] + 128) % 256) - 128.0
    local y = ((accel[1] + 128) % 256) - 128.0
    local z = ((accel[2] + 128) % 256) - 128.0
    
    averageX = averageX * exponentialFactor + x * (1-exponentialFactor)
    averageY = averageY * exponentialFactor + y * (1-exponentialFactor)
    averageZ = averageZ * exponentialFactor + z * (1-exponentialFactor)
    
    local motion = math.abs(x-averageX) + math.abs(y-averageY) + math.abs(z-averageZ)
    
    if(motion > 5 && warmup > 3/(1-exponentialFactor)) {
        server.log(format("triggered! %d", motion))
    } else {
        warmup += 1
    }
}

poll()

imp.configure("Vibration sensor", [], [out])