Smartmaker's temperature example.

hannah-rev3-tmp112.squirrel.js

imp.configure("Temperature Logger", [], []);

const i2c_temp  = 0x92;
hardware.configure(I2C_89);
local i2c = hardware.i2c89;
function ShowTemperature(){
    //Poll the temperature every n seconds
    imp.wakeup(5,ShowTemperature);
    i2c.write(i2c_temp, "\x01\xE1\x30");
    imp.sleep(0.050); //50 ms vs rated time of 26 ms
    local result = i2c.read(i2c_temp, "\x00", 2);
    local t;
    if(result[1] & 1) { //Extended, 13-bit, mode
        //server.log("[DEBUG] Received 13-bit extended mode value");
        if(result[0] & 0x80) {
            //Extend the 13-bit two's complement
            //server.log("[DEBUG] Received negative extended mode value");
            t = 0xFFFFE000 | ((result[0] << 5) | (result[1] >> 3));
        } else {
            t = ((result[0] << 5) | (result[1] >> 3));    
        }
    } else {
        //server.log("[DEBUG] Received 12-bit normal mode value");
        if(result[0] & 0x80) {
            //Extend the 12-bit two's complement
            //server.log("[DEBUG] Received negative normal mode value");
            t = 0xFFFFF000 | ((result[0] << 4) | (result[1] >> 4));
        } else {
            t = ((result[0] << 4) | (result[1] >> 4));    
        }
    }
    
    //local temp = t * 0.0625; //Celsius
    local temp = t * 0.1125 + 32; //Fahrenheit
    agent.send("temperature", temp);
}

// Configure the tmp112 for one-shot reading (shutdown mode)
i2c.write(i2c_temp, "\x01\x61\x20");
imp.sleep(0.1); //100msec to reconfigure

ShowTemperature();