$fn = 50;

width = 24;
length = 119;
height = 22;

corner_radius = 2;
wall_thickness = 2;
post_diameter = 8;
post_height = 0;

hole_diameter = 3;
lid_thickness = 1.9;
lid_lip = 1 ;
lid_tolerance = .5;


module posts(x, y, z, h, r){
    translate([x, y, z])
      cylinder(r = r, h = h);

    translate([-x, y, z])
      cylinder(r = r, h = h);

    translate([-x, -y, z])
      cylinder(r = r, h = h);

    translate([x, -y, z])
      cylinder(r = r, h = h);
}



difference() {
    // box
    hull() {
        posts(
            x=(width/2 - corner_radius), 
            y=(length/2 - corner_radius),
            z=0,
            h=height,
            r=corner_radius);
    }
    
    // hollow
    hull() {
        posts(
            x=(width/2 - corner_radius - wall_thickness), 
            y=(length/2 - corner_radius - wall_thickness),
            z=wall_thickness,
            h=height,
            r=corner_radius);
    }

    // lip inside box
    hull() {
        posts(
            x=(width/2 - corner_radius - lid_lip), 
            y=(length/2 - corner_radius - lid_lip),
            z=(height - lid_thickness),
            h=(lid_thickness + 1),
            r=corner_radius);
    }

    // ventilation slits left 1
    for(i = [(wall_thickness+post_height+3):4:(height-5)]) {
        translate([(-width/2)-wall_thickness, (-length/2)+25, i])
            cube([10, length/5, 2], center=true);
    }

    // ventilation slits left 2
    for(i = [(wall_thickness+post_height+3):4:(height-5)]) {
        translate([(-width/2)-wall_thickness, (length/2)-25, i])
            cube([10, length/5, 2], center=true);
    }

    // ventilation slits right 1
    for(i = [(wall_thickness+post_height+3):4:(height-5)]) {
        translate([(width/2)-wall_thickness, (-length/2)+25, i])
            cube([10, length/5, 2], center=true);
    }

    // ventilation slits right 2
    for(i = [(wall_thickness+post_height+3):4:(height-5)]) {
        translate([(width/2)-wall_thickness, (length/2)-25, i])
            cube([10, length/5, 2], center=true);
    }

    // network connector hole 1
    translate([0, (length/2), wall_thickness+2+10])
        cube([17, 6, 20], center=true);

    // network connector hole 2
    translate([0, (-length/2), wall_thickness+2+10])
        cube([17, 6, 20], center=true);

    // sensor hole
    translate([(width/2), -7, wall_thickness+2+6])
        cube([5, 10, 7], center=true);

}


// support posts for pcb
/*difference() {
    translate([0, length/4, wall_thickness])
        cylinder(r = post_diameter/2, h = post_height);

    translate([0, length/4, wall_thickness])
        cylinder(r = hole_diameter/2, h = post_height+3);
}


difference() {
    translate([0, -length/4, wall_thickness])
        cylinder(r = post_diameter/2, h = post_height);

    translate([0, -length/4, wall_thickness])
        cylinder(r = hole_diameter/2, h = post_height+3);
}
*/