In Intro to Physical Computing, many projects require a skill of soldering. For those who don’t know, soldering is the practice of conjoining two metal materials together by the melting of a third material (solder) that melts and bridges the two metals together. Soldering is used in almost every project in the class. Examples of where soldering is applicable to this class is the joining of wires on a circuit board, of wires to a module, or wires to other wires, to name a few. However, this class having no prerequisites, it is not guaranteed that everyone knows how to solder, or solder properly. This tutorial is to show a beginner how to via soldering two wires together.

Materials

The first thing is to make sure you have all the materials needed to solder. This includes:

Safety Goggles:

Soldering Iron:

60/40 Rosin Core Solder Spool:

Fan:

Third Hand Soldering Stand with Magnifying Glass & Sponge:

Wire Stripper:

Wires:

Safety goggles are important as soldering involves melting metals at a high temperature, so it is imperative to protect your eyes when in the process of soldering. Solder comes in various shapes, lengths, and sizes, for many different applications. It is very important that the solder you are using Rosin Core Solder as it has rosin flux which is used to help the metals from oxidizing, which tends to happen at high temperatures. With oxidation, it is almost impossible for you to be able to solder properly. It is also ideal to use 60/40 solder, which is used commonly in applications that are used in Physical Computing such as soldering electronics. The one I am using is Rosin Core Solder from Radioshack® There are many versions of soldering irons out there that have different Power requirements for different applications. The soldering iron tool from Weller®, is a 25 Watt single temperature soldering iron that heats up to 750 degrees Fahrenheit. This is the typical power needed for a soldering iron to melt solder that is used for applications such as electronics and circuitry work. Although it only heats to a single temperature, it is effective in melting the Rosin Core Solder. Offered in class is the Hakko® FX888d soldering station, that gives the user a wider range of temperatures, allowing the user to heat up the soldering iron up to almost 900 degrees, although it isn’t recommended to.

The third hand station can be very useful when Soldering. It can hold the soldering iron as well as up to two metal parts (be it wires or circuit boards) through its two alligator clips. (Note: be careful if using the alligator clips to hold a circuit board, as it is possible to damage the board doing so). The sponge at the bottom is necessary to clean off the soldering iron after soldering so it can be used again. The magnifying glass, is also important so one can have a close up view when soldering for better accuracy. I got mine also from Radioshack® Some stations, such as the Hakko used in Physical Computing, have flux installed into the station as well, this way after soldering, the user can simply rub the soldering iron tip into the flux so it can be used again with less fear of the tip oxidizing. It is also recommended to have either a Fume Extractor (provided in Physical Computing) or a fan when soldering. The fumes made from the melting of solder can be very dangerous if inhaled for extended periods of time.

Soldering Tip(s):

Almost all soldering irons have removable tips so that the user can use which soldering tip that bets suits them. I personally use the round cone tip when soldering, however, especially for beginners, it is heavily recommended to use a flat head tip for soldering. It gives the user more surface area on the soldering iron, when soldering.

Setting Up:

It is important to remember to wet the sponge on the soldering base, although it’s easy to remember, it is also easy to forget to wet the sponge, as placing the soldering iron on a dry sponge will cause the sponge to burn and shorten its lifespan.

No:

Yes!:

The next step is to take the two wires we want to solder together, and strip them using a wire stripper. This will give us more space to put solder on the wire, thus creating a larger bond between the two wires

Now simply place the wires into the two alligator clips of the third hand stand, one wire to each alligator clip. Then adjust the third hand stand such that the wires are touching each other. Before soldering, an important step is the process called tinning. Contrary to the name, the only time solder is actually placed on the soldering iron, is this step. In the process of tinning, you want to turn on your soldering iron, in this case plug it in, and wait 60 seconds for it to reach the target temperature. Then, you want to take some solder from your spool of solder, and gently rub the solder onto the soldering iron, but only enough to cover the tip, you do not want globs of solder to form onto the soldering iron. The process of tinning is to reduce the chance of oxidation when soldering as well as to help make the soldering process quicker. Then, once this is done, Place the soldering iron below the exposed section of the wires and the solder above. This will create a heat bridge in which from the soldering iron heating up the wires, the wires will then cause the solder to melt on them. Then move both the soldering iron and solder slowly from left to right to completely cover the exposed section in solder. Use the magnifying glass as help if necessary for a closeup view. It should go as seen in the video below:

If done correctly, the result will look like this:

As an added bonus, I also added how to solder on a circuit board. This circuit board being the Personal Portable Server Prototype of my Father and I’s startup, Toyz Electronics. This video is a demonstration of me (re)soldering the battery onto the board using the steps above. (for more information on the Personal Portable Server: https://www.youtube.com/watch?v=hbpiUyZQ3nM  or go to tngl.biz)

Final Product:

Thank you:
Video recorded on my Wifi Smart Glasses, a product of Toyz Electronics

Ghosty is an autonomous little robot who is adventurous and loves to explore his surroundings. However, unlike a normal ghost, he doesn’t like to scare people. Instead they actually scare him! In our most current version of Ghosty, his vision line is based on the data of two proximity sensor data reads. The difference between the data of the two proximity sensors determine whether the motors that control the wheels of Ghosty will go forward or backward and what acceleration (bigger difference equals greater speed).

Technical Details

Ghost was set up according to the above circuit diagram. There were two proximity sensors, both powered by the 5 volt pin on the arduino board. These sent readings to the arduino, which checked the difference between the values and turned the robot left or right if there was a significant difference between them. The difference between the proximity sensors caused a certain combination of high and low values to be sent to the motor pins, controlled through an integrated circuit that was able to operate two motors simultaneously.

The above circuit diagram is a modified version of the circuit diagram seen below:

Motor Control:

Upon reaching out to Dr.Ali  from prior iteration (Ghosty II), It was decided the DRV 8833 Motor Controller (source: http://www.pololu.com/file/0J534/drv8833.pdf ) would be best to control the motors for Ghosty. After working with Dr.Ali, a program that works with the DRV 8833 Motor controller was made. The Arduino was able to send data to the Motors was using the DRV 8833, which has the ability to drive two motors simultaneously and send signals from the arduino and relay them to the motor.

The way the motor driver works is it reads two different data forms, by sending LOW/HIGH to the pin labeled BIN2, the motor driver would tell whichever motor connected to that pin to move at a slow decay if it is set to HIGH, and fast decay if it is set to LOW. Then it would move at a forward motion at a rate determined by the difference between the data read by the two proximity sensors. If sent data to BIN1 LOW/HIGH, the motor connected to the pin will also move at a slow decay if sent to HIGH and fast decay if it is set to LOW, however it will now move in reverse motion based on the difference between the data recorded from the two proximity sensors. The same conditions also apply to pins AIN1 and AIN2. BIN1 or BIN2 (as well as if AIN1, AIN2) is fed a positive value (determined by if the proximity sensor connected to A1 on the arduino reads that an object is further away from it than it is the proximity sensor connected to A0) and a negative value if A0 reads an object is further away from it than it is the proximity sensor connected to A1. If fed a negative value then the motor will move in a reverse motion and if positive, will move in a forward motion. The combination of the motors determines which direction Ghosty will go. The motors themselves (from prior iterations in Ghosty II), Solarbotics GM9 Gear Motor (http://www.pololu.com/product/188/resources  )  required around 9V of power each to show any noticeable change, which, in the current iteration was supplied by battery (Code from prior iteration (Ghosty II) Shown Below):                     ArduinoDistance

Servo:

Originally in prior iterations (Ghosty 2) it was decided that the arduino would be controlled by pins 9/10 from the Arduino, such that if a proximity sensor read that an object is close, Ghosty will move its arms (servos) in an upward motion, however it was decided it would be more efficient to use these pins for motors instead. The servos were originally powered by A 5V Step Up Regulator. Code shown below:                ArduinoDistanceWithServo

Puredata:

Research was done in regards to integrate puredata in the 3rd edition of Ghosty using sensors & arduino, however, under given time constraints, it was decided not to.  http://forum.pdpatchrepo.info/search/arduino-sensors.

Photos

Video: