Electronic Lunch 8/11

We had another successful Electronic Lunch this week, Dan Charette came in and taught us some tips for soldering electronics!

First he discussed how there are two different types of solder:

Rosin based- use with electronics:

Acid based- used for copper piping and will eventually ruin electronics

Tinning the Tip of the Soldering Iron:

- Flux in the solder must be cleaned off the tip. If it is left on the tip will turn black and not conduct heat as well. Eventually it can cause permeant damage.

-clean the flux off my wiping the tip on the sponge- the flux is gone when the smoking stops. (you can also use a cup of brass shavings)

- add solder to the tip of the iron until the tip is completely covered and shinny.

- You only need to tin the tip once per soldering session

What to look for in a well soldered connection:

- Shinny- If it is dull grey the iron wasn't hot enough

-Concave- If the iron was hot enough and all of the pieces where properly heated than the solder should be pulled down into the joint- If not you might see bubbling and solder might get in places you don't want it- creating connections you don't want.

- wiggle the components, they shouldn't fall off!

Steps:

- Clean the board, with 400 grit sandpaper or a gum eraser.

- start with smaller components like diodes or resistors. These are will keep the board flatter for longer. If board wobbles use a vice.

-Save the sensitive components for last. This will decrease the chances for you to damage it or that it will overheat. Also think about using a heat sink while soldering. By putting a clip on the component (on the opposite side of the board from where you are welding in between the board and the component) will keep it from overheating.

-Hold the soldering iron to wire and the board heating both of them at the same time. After 3-4 seconds melt solder on to the joint on the opposite side of the wire (don't touch the tip of the iron to the solder or the solder will just run up the tip and not on to the joint).

-The solder should melt in 3/4 seconds- if not turn up the heat. Also try using more of the side of the tip on the soldering iron, more surface area equals more heat.

-remove the solder first then the tip of the iron or the solder will stick to the joint.

Electronic Lunch 7/21

On Wednesday we discussed the future of Electronic Lunch. We are going to continue working through the Arduino tutorials and working on a group project. We are planning on making a shield together, a board with built in inputs and outputs, that allows the user to easily plug in motors and sensors to prototype quickly. This will allow us to learn more arduino together and create a useful tool for DL1.

Electronic Lunch 7/14

The first Electronic Lunch of the summer was very successful! We had 16 participants this week which included architects,

middle school teachers, Groundworks staff, U of M professors, a brother from Massachusetts, and robotics experts. Thank you all for coming and a special thanks to Bilal, Andrew, and Alex from Robotics Redefined for the first gr

eat lesson.

We will be hosting Electronic Lunch in DL1 every Wednesday from 12-1pm as a support group for people working to learn about microprocessors. If you want to get started on your own check out the links in the blog post bellow. The book, Getting Started with Arduino by Massimo Banzi, is available online through the U of M library (http://proquest.safaribooksonline.com/9780596155704).

In Lunch we had an overview of the Arduino. We discussed how Arduino is " an open source physical computing platform based on a simple input/output (I/O) board and a development environment that implements the Processing language (www.processing.org)."

Which means that you can have the Arduino parts a quickly prototype a circuit and program it with open source software that you can download free offline.

Bilal discussed how circuits must be a complete loop to function. Electrons have to flow a certain path from the + positive to the - negative or ground and we can manipulate them on this path to do work for us. (Bilal used the analogy of a house)

Bilal walked us through the different parts to an Arduino board including the breadboard, diodes, and resistors. Resistors convert energy in the circuit to heat and dissipate it so thing do not fry. The color code on the side of the resistor lets us know how much they are resisting. Andrew taught us an easy was to remember the code:

0 Black (bad)

1 Brown (beer)

2 Red (rots)

3 Orange (our)

4 Yellow (young)

5 Green (guts)

6 Blue (but)

7 Violet (vodka)

8 Grey (goes)

9 White (well)

( The gold and silver indicate tolerance)

The best way to get familiar with Arduinos is by prototyping with them and playing. Bilal started us off by walking through one of the first exercises, making an LED blink. The instructions can be found online as well (http://www.ladyada.net/learn/arduino/index.html).

If you want to try this exercise again feel free to come into DL1 and use the Arduino boards we have available here. We are open 12-9pm M-Th and 12-4 on Fridays. You can also apply for 24 hr key card access.

We hope to see you at next weeks Electronic Lunch!

Electronic Lunch #2- Learning the basics of the micro processor (Ardunio)

To keep in mind:
Voltage: the potential for electrical energy

0= off 1= on, high voltage

Computer language is binary written with 1's and 0's

Binary is base two, just like decimal (the standard number format) is base 10.

This means that a binary number can be viewed as an addition of powers of two, just like a decimal number can be viewed as an addition of powers of 10.

i.e.
The number:
1778
Can be seen as:
1*10^3 + 7 * 10^2 + 7*10^1 + 8*10^0 = 1000 + 700 + 70 + 8 = 1778

For binary:
11010 = 1 * 2^4 + 1*2^3 + 0*2^3 + 1*2^2 + 1*2 + 0*2^0 = 26 (In decimal)


Computers can:
1) senses info
2) remembers data for later use
3) adds

Writing the code to send to the board (you can use programs such as Arduino and Processing)

-written in C, and then converted into binary by a compiler

-Digital pins read 5 volts so they are either on or off (If the board's operating voltage is 5V)
-On and off is represent by 1 and 0 respectively

-Analog- read voltages between 0-5 (If operating voltage is 5) then it goes through a special circuit that converts analog to digital (binary) number which represents the voltage.

-a function is a list of commands


Links:
http://arduino.cc/
http://www.ladyada.net/learn/arduino/index.html
http://www.processing.org

Electronic Lunch: How to Solder #1

Practicing Joining Wires by Soldering...

Soldering- connecting pieces without losing electric conductivity.

You need:

- soldering iron

- soldering wire

- damp sponge (to keep tip of iron clean)

- wire to join (we used old speaker cable)

- wire stripper

- something to hold the pieces while you work

- electrical tape

Tips:

- heat the work not the solder

- solder melts QUICKLY, much faster than material you are connecting

- avoid Cold Joints: didn't use enough heat- won't conduct signal and might physically come off.

Steps:

1- Strip the jacket off the wire, don't cut into the wire.

2- Tin the wire.

- this is putting some solder on the wire before you connect them so that connecting them goes smother.

- If the solder stays a ball on the wire than its not hot enough

- put solder on until wire ends are covered, turn silver

- work towards the tip

- once it flows it goes

3- Twist the wire together

-twist ends together and fold back on itself (make sure both ends get twisted)

4- Solder this joint

5- Cover in electrical tape