+ ;; the construction of the first item is heavily commented.
+ ;; the higher amount of commenting is intended to make it clear
+ ;; how the code works to new readers
+ (make-item (string-append
+ ;; this is the argument for the parameter 'description'.
+ ;; it's a description of the orange wire. this is for
+ ;; documentation.
+ "solid core orange 22 awg wire, male-male jump wire."
+ " units in mm. makes electrical connection between"
+ " arduino and motor controller, used for backwards"
+ " enabling.")
+
+ ;; this is the argument for the parameter 'quantity'.
+ ;; this is the number of millimeters of orange wire
+ ;; in a single robot kit.
+ ;; there are 2 orange wires, one for each wire.
+ ;; the 120 mm wire reaches to the far side of the
+ ;; motor controller
+ (+ 120 90)
+
+ ;; this is the argument for the parameter 'unit-cost'.
+ ;; the cost on jameco is 7.95 for 100 feet.
+ ;; this calculation converts from dollars per foot to
+ ;; dollars per millimeter.
+ ;; there are 100 feet, 12 inches per foot, 2.54 cm / inch,
+ ;; and 10 mm / cm.
+ ;; the product of all these numbers is the number of
+ ;; millimeters purchased with $7.95
+ (/ 7.95 (* 100 12 2.54 10))
+
+ ;; this is the argument for the parameter 'max-lead-days'.
+ ;; since the part is at jameco, i can pick it up same day.
+ 1
+
+ ;; this is the argument for the parameter 'where-to-get'.
+ ;; it is a url where the part can be purchased.
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_2154871_-1"))
+
+ (make-item (string-append
+ "solid core blue 22 awg wire, male-male jump wire."
+ " units in mm. connects motor controller and arduino,"
+ " used for forwards enabling.")
+ (+ 120 90)
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36768_-1"))
+ (make-item (string-append
+ "solid core white 22 awg wire, male-male jump wire."
+ " units in mm. connects motor controller and arduino,"
+ " used for speed signal.")
+ (+ 120 90)
+ ;; cost of 1 mm
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36881_-1")
+ (string-append "unit cost goes down for large orders,"
+ " see page for specifics"))
+ (make-item (string-append
+ "solid core green 22 awg wire, male-male jump wire."
+ " units in mm. connects motor to breadboard.")
+ (* 2 175)
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36822_-1"))
+ (make-item (string-append
+ "solid core yellow 22 awg wire, male-male jump wire."
+ " units in mm. connects motor to breadboard.")
+ (* 2 175)
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36920_-1"))
+ (make-item (string-append
+ "solid core red 22 awg wire, male-male jump wire."
+ " units in mm. connects power for all components.")
+ (+ (* 2 30) 25 25)
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36856_-1"))
+ (make-item (string-append
+ "solid core black 22 awg wire, male-male jump wire."
+ " units in mm. connects ground for all components.")
+ (+ (* 30 2) (* 4 25) 25 55)
+ (/ 7.95 (* 100 12 25.4))
+ 1
+ (string-append
+ "http://www.jameco.com/webapp/wcs/stores/servlet/Product"
+ "_10001_10001_36792_-1"))
+ (make-item "4xAA battery"
+ 4 (/ 17.99 100) 1
+ "http://www.frys.com/product/6292850"
+ "can get in store")
+ (make-item "4xAA battery holder"
+ 1 2.25 1
+ (string-append
+ "http://shop.evilmadscientist.com/"
+ "productsmenu/partsmenu/422")
+ (string-append
+ "can get in store. unit cost goes down for large orders"
+ ", see page for specifics."))
+ (make-item "angle bracket, 1/2 inch sides with #6-32 threaded hole"
+ 4 0.75 1
+ (string-append
+ "http://shop.evilmadscientist.com/productsmenu/partsmenu"
+ "/465-bracket")
+ (string-append
+ "can get in store. unit cost goes down for large orders"
+ ", see page for specifics."))