+ :title [arduino to deck]
+ (p [let's attach the arduino to the deck.])
+ (subsection
+ :title [required materials]
+ (p [you will need the things in this picture.
+ ,(figure :legend "arduino to deck / required materials"
+ (image :file "arduino-to-deck/0-required-materials.png"))
+ ,(itemize
+ (item [medical kit with bandages])
+ (item [safety goggles])
+ (item [drill bit \(we will determine size in a moment\)])
+ (item [drill])
+ (item [alan wrench])
+ (item [wood block])
+ (item [arduino])
+ (item [#6-32x3/8\", four of them])
+ (item [robot deck, the white thing with a grid of holes1]))]))
+ (subsection
+ :title [first hole]
+ (subsubsection
+ :title [choosing drill bit]
+ (p [the arduino comes with holes in it already, so we will make
+ some choices around those holes.
+ choosing the right drill bit depends on what job you are
+ doing.
+ right now, we are making holes for screws to hold the
+ arduino to the deck.
+ there are two constraints between the hole and screw.
+ each hole needs to be big enough for the screw body to fit
+ through it.
+ the holes also need to be smaller than the screw's thread.
+ since there are holes on the arduino already, the screw was
+ chosen to match it.
+ the screw was chosen so that the hole on the arduino was
+ bigger than the screw body and smaller than its thread.
+ we will choose the biggest drill bit that fits through the
+ hole on the arduino, then use that to drill holes in the
+ deck.])
+ (p [here's a cross section of a screw in the deck]
+ (figure :legend "screw cross section"
+ (image :file
+ "arduino-to-deck/screw-cross-section.png")))
+ (p [check
+ ,(itemize
+ (item
+ [what would happen if the drill bit were larger than the
+ screw thread?])
+ (item
+ [what would happen if the drill bit were smaller than the
+ screw body?]))]))
+ (subsubsection
+ :title [inserting drill bit]
+ (p (figure :legend "arduino to deck / insert bit"
+ (image :file "arduino-to-deck/1-insert-bit.png"))
+ [insert the drill bit into the teeth of the drill.
+ insert it far enough that the teeth will clamp on the
+ smooth part of the bit when they are tightened.])
+ (p (figure
+ :legend "arduino to deck / twist tighten drill teeth"
+ (image :file "arduino-to-deck/2-twist-tighten-drill-teeth.png"))
+ [while holding the drill bit, twist end of the drill to tighten
+ the teeth.
+ make sure that the teeth end up gripping the flat part of
+ the drill bit.])
+ (p [check
+ ,(itemize
+ (item
+ [where should the teeth clamp down on the drill bit?])
+ (item
+ [what would happen if the teeth tightened on the recessed
+ part of the drill bit?]))]))
+ (subsubsection
+ :title [holding drill]
+ (p [hold the drill with one hand on the handle and trigger.
+ put the other hand on the orange nozzle, before the
+ black spinning part.]))
+ (subsubsection
+ :title [arduino placement]
+ (p [the arduino should be placed as shown in this picture.]
+ (figure :legend "arduino to deck / place arduino"
+ (image :file "arduino-to-deck/3-place-arduino.png")))
+ (p [here's a closeup]
+ (figure :legend "arduino to deck / place arduino closeup"
+ (image :file
+ "arduino-to-deck/4-place-arduino-closeup.png"))
+ [the picture above shows where to place the arduino on the deck.
+ the arduino should line up with the holes on the deck.
+ this alignment line is highlighted in pink.
+ on the arduino, there's a hole on the top left, between the
+ orange reset button and black headers.
+ the green circle shows where the hole is.
+ the blue box encloses the arduino hole and two deck holes.
+ place the arduino hole mid-way between the two
+ deck holes.])
+ (p [check
+ ,(itemize
+ (item
+ [should the arduino be upside-down?])
+ (item
+ [what should the upper side of the arduino align with?])
+ (item
+ [why not place the arduino up along the left side of the
+ robot?]))]))
+ (subsubsection
+ :title [drilling practice]
+ (p [strength check]
+ (itemize
+ (item [put on safety goggles])
+ (item [unplug drill])
+ (item [hold drill in one hand])
+ (item [point drill at the ground])
+ (item [point drill at the wall])))
+ (p [steps for drilling into wood block]
+ (itemize
+ (item [plug in the drill])
+ (item [place the drill bit in position])
+ (item [bring the drill up to full speed, and keep it at full
+ speed while lowering and raising the drill])
+ (item [push down until the drill bit has passed through an inch
+ of the wood block])
+ (item [keep the drill at full speed])
+ (item [stop before the drill smashes into the wood block])
+ (item [keep the drill at full speed by holding the trigger])
+ (item [bring the drill straight back up])
+ (item [hold the trigger down to keep the drill at full speed])
+ (item [once the drill is back out of the hole, let go of the
+ trigger])))
+ (p [check
+ ,(itemize
+ (item
+ [should the drill be at full speed while the drill bit is
+ going down into the wood and coming back up?])
+ (item
+ [how do you keep the drill at full speed?])
+ (item
+ [what would happen if the drill bit were not at full
+ speed?])
+ (item
+ [what would happen if the drill were twisted sideways while
+ the drill bit were in the wood?]))]))
+ (subsubsection
+ :title [drilling the first screw hole]
+ (itemize
+ (item [place the drill bit in position])
+ (item [bring the drill up to full speed, and keep it full speed])
+ (item [push down until the drill bit has passed through the
+ deck])
+ (item [keep the drill at full speed])
+ (item [stop before the drill smashes into the arduino])
+ (item [keep the drill at full speed by holding the trigger])
+ (item [bring the drill straight back up])
+ (item [hold the trigger down to keep the drill at full speed])
+ (item [once the drill is back out of the hole, let go of the
+ trigger]))
+ (p [check
+ ,(itemize
+ (item
+ [should the drill be at full speed while the drill bit is
+ going down into the wood and coming back up?])
+ (item
+ [what would happen if the drill bit were not at full
+ speed?])
+ (item
+ [how do you keep the drill at full speed?]))])))
+ (subsection
+ :title [first screw]
+ (subsubsection
+ :title [fastening arduino to deck using #6-32x3/8\" screw]
+ (p [the "#6" part of "#6-32x3/8\"" is how big around the bolt is.
+ it is related to wire gauge.
+ bigger numbers mean larger screws.
+ smaller numbers means smaller screws.]
+ (figure :legend "arduino to deck / #6-32 screw"
+ (image :file
+ "arduino-to-deck/6-32-screw.png")))
+ (p [check
+ ,(itemize
+ (item
+ [in the motor assembly, there are #4-40x1.25\" screws.
+ are those fatter, thinner, or the same thickness as the
+ #6-32x3/8\" screws?]))])
+ (p [the "32" part of "#6-32x3/8\"" is a measurement of how close
+ the threads are to each other.
+ this is related to the angle of the thread, which is also
+ called pitch.
+ it is a count of how many times the thread wraps around one
+ inch of the screw body.])
+ (p [the head is the flat part where some tool, like the alan
+ wrench, can exert force to spin the screw.])
+ (p [check
+ ,(itemize
+ (item [how many times will the thread wrap around one inch of
+ the screw body?])
+ (item [what about 2 inches?
+ how many times will the thread wrap around two
+ inches of the screw body?])
+ (item [where can a tool exert turning force on
+ the screw?]))]))
+ (subsubsection
+ :title [fasten the arduino board to the deck]
+ (p [first we'll put the screw into the deck just enough so the deck
+ holds it in place.
+ then we will hold the arduino up to the screw and finish
+ tightening the screw down.
+ with the screw partially in, we do not have hold it as
+ rigidly while we are also holding the arduino and
+ the deck.])
+ (p [push the #6-32 screw into the deck from the underside.
+ the underside is the brown side.
+ at the same time, spin the 6-32 screw so it rotates
+ clockwise while looking down on its head.
+ twist until the tip of the screw is about to stick out on
+ the top side of the deck.])
+ (p [hold the arduino board flat to the deck and line up the arduino
+ hole so the screw can come up through it.
+ continue tightening the screw into the deck, spinning the same
+ direction as before.
+ tighten until the screw head touches the deck.
+ do not continue tightening after that.])
+ (p [the arduino should still be flat against the deck still, just
+ as it was before tightening the screw.])
+ (p [check
+ ,(itemize
+ (item [why do we insert the first screw partially before
+ holding up the arduino?])
+ (item [which side of the deck is the top side?]))]))
+ (subsubsection
+ :title [assessment of the first screw]
+ (itemize
+ (item [,(bold [warning]), if you rotate the arduino board too
+ much,you will unscrew it from the deck and you'll have to
+ screw it back in.
+ rotating a few degrees should be ok.])
+ (item [does the arduino stay with the deck when the deck moves?])
+ (item [can the arduino board still rotate a few degrees?]))))
+ (subsection
+ :title [second hole and screw]
+ (subsubsection
+ :title [arduino board move relative to deck]
+ (p [without any screws, the arduino board can move independently of
+ the deck.
+ it can translate and rotate freely.
+ with the first screw, the arduino can rotate around one
+ point on the deck and can no longer translate much.])
+ (p [the second screw limits rotation a lot.
+ it also makes translation even more difficult.
+ it might even be too small to be detectable by directly
+ looking at it.])
+ (p [to choose where the second hole and screw should go, we should
+ keep in mind that the goal is to attach the deck to the
+ arduino.
+ this means minimizing rotation and translation.
+ the picture below shows that the second hole should be as
+ far as possible from the first hole, since that minimizes
+ rotation.]
+ (figure :legend "arduino to deck / keep holes far apart"
+ (image :file "arduino-to-deck/keep-holes-far-apart.png"))))
+ (subsubsection
+ :title [drilling and attaching screw]
+ (p [to drill the second hole, follow the same steps as drilling the
+ first hole.
+ hold the arduino down as before, and drill through the hole
+ furthest away from the first hole.])))