User:Batmaneatsgrass/project 3

My Instructor's user page which points to this.

Project 3 : Useless Baby Box

Week1 Narrative

 * During the first week I gathered materials and created a mini-prototype. First, I got two baby dolls, a large one and a small one, from a thrift store called Second Avenue and a couple of baskets which I would've used as a box. One basket had a heavy lid while another one had no lid. I tried fitting the babies properly in each basket to see how easy it would be for them to pop out, but the basket wall got in the way each time. The baskets were too deep and not wide enough. This is where the idea for the shoe box came in. It was the correct size for the smaller baby. I then hot glued a stick onto a Radioshack servo motor and attached the baby to that. I then tested out which wires were which for the servo - purple negative, yellow positive, orange signal. I then cut the lid of the box to make a smaller lid that the servo would easily be able to push up. I glued the servo to the box and connected it to the arduino. Then, I glued the servo onto the bottom of the box, making sure that the baby's head wouldn't interfere with the back of it. I used a code from Vincent, my project partner, to make the servo move at intervals to make the baby come out of the box. The baby's legs were interfering with the servo and had to bee cut off. Its arms also had to be tied together because they were interfering with the hole cut in the lid of the box.

Week2 Narrative

 * During this week I came up with some possible designs that included a switch and light and started building. I bought toggle light switch at walmart and also some extra 9V batteries since some of the ones I had were dead.The light switch would be attached to a piece of wood facing the front of the box so the baby can reach over and move it. The light would be behind the box and the wires going from the switch to the light can go under the box or be taped to the side of it. The breadboard, batteries, arduino, and motor shield also needed for the project can go inside the box. One idea for moving the baby's arms was to have a stepper motor with gears, but then I realized that one motor wouldn't be enough. The new plan became to have a servo be inside of the baby and control one arm. If possible, two servos would be better to ensure the switch would be turned off. I could not find a second workable servo so I decided to just go with one and keep a lookout for any others. A stepper had to be used to move the baby itself up to ensure the baby would stay in place and not move back while the servo would move the baby's arm. One the switch would be turned on by a person, a light would turn one, and a photoresistor would send feedback into the arduino which would tell the stepper and servo to move the baby out of the box. When the light would be turned off, the photoresistor would no longer send feedback and so the baby will go back down. I found a string of LEDs and checked that they would work with the switch and with a 9 volt battery while my partner confirmed that the photoresistor was reacting to the LEDS. I also screwed on the switch onto a long, narrow piece of wood so it could be more easily attached to other pieces.

Week3 Narrative

 * I tested the servo by itself with the switch to make sure it was strong enough and it was able to turn the switch. I took the baby off the servo and glued a stick onto the servo so that it could move the baby's arm. The stick was straight while the arm was curved so it wouldn't go through the arm and not enough leverage was created, so i decided to use a wire. I bent it into the same bend the arm was and glued it onto the servo. Then, I found a gear to fit the stepper and glued a piece of wood onto it that could hold the stepper and baby. I had cut the piece of wood to be maximum length without interfering with the hind wall of the box. After comparing it to the baby, I cut more off so the baby's head can go in the spot of the wood because the wood was causing the head to bulge forward and restrict the movement of the arms. Then I attached the servo to the wood with zip ties and electric tape. Then I attached the baby with zip ties so that where the servo turns would be at the shoulder of the arm to decrease resistance and increase torque. Because the stuffing got in the was I had to pull some out. I also cut some cloth at the shoulder because it was causing too much resistance.

Week4 Narrative
I tried to get the stepper motor to work by trying various wire combinations, but nothing would cause it to work even though the LED on the motor shield lit up when I spun the motor. The code I was using was guaranteed to work because I saw it working in a youtube video with the same exact motor (stm-100) and the same exact wire setup that I had. I also tried replacing the adafruit motorshields with the same type but just different ones lying around in the lab. When this still didn't work, I determined that it is broken and ordered a new one - when it comes in I hope the project will work.