read an high precision adc like hx711

Hi,
I stumbled upon THIS webpage for the electric imp.
Github link to the code
It has implemented the read function using :

function read_weight(){
    //This is bit banged so we 
    //bind calls to local variables
    //to speed things up.
    //Takes about 2.2mS to do the read
    local sw  = spi.write.bindenv(spi);
    local dr  = data.read.bindenv(data);
    local val = 0;

    for(local i = 24; i >= 0; i--){
        sw(PULSE);
        val += dr() ? math.pow(2, i) : 0;
    }

    return (val-ZERO_OFFSET)/GAIN;  //Value in grams
}

It does point out that I should have typed >0 in the for statement not 1...
I will test my code again with the refinements suggested by Gordon later tonight hopefully and will report back.

Many thanks,

Aaron