Mini Sumo Electronics Tutorial F10

outLINE

• Quick Intro to Circuit Theory• Board Overview• Components and Soldering• Testing and Debugging• General Advice

Resistors

• Governed by Ohm’s Law

• Nice and simple• Used as current limit, or to drop/lower

voltages

Capacitors/Inductors

• Capacitors • Inductors

Hey Look! Calculus...?

cap/inductorNOTES

• Fun fact, you can get rid of the derivatives!• You will hear the word “impedance” thrown around.• Basically, we consider everything with reference to

frequency rather than time (huh?).• You will see this applied without explanation in 1st year,

and then explained in 2nd. • You will spend ~two years studying the previous slide(s),

so don’t worry if it seemed frightening.

Diodes & LEDs

• Only conduct in one direction. That of the “arrow”.• For our purposes, “turn on” when the “arrow” is more

positive than the “line”.• LEDs (= Light Emitting Diodes), emit well...light.

boardOVERVIEW

• Custom 2 layer design, updated this Summer

• Based around Atmel’s ATMega168 AVR microprocessor

• We use two separate power supplies, one 6V (4xAA) and one 9V.

blockDIAGRAM

ATMega168

RS232

Motor Drivers

Voltage Sensing

Status LEDs

2x IR DistSensors

SPI

2x LineSensors

Voltage Regulation

6V9V

boardCOMPONENTS

Schottky Diode (Polar)

MAX232NSR

L293d

ATMega168v

LED (Polar)

Resistor

Capacitor

Electrolytic Capacitor (Polar)

LD1117 5V Regulator

100mil Header Right Angle Header

Negative

Match to stripe on board

Pin 1 Marker

100 + 2 zeros = 10k

Ferrite

8 MHz Oscillator

solderingBASICS

• Soldering: Use of a hot iron to melt a tin alloy in order to electrically connect components to a circuit board

Image courtesy of SparkFun Electronics

solderingTIPS• Iron temp is usually set to ~70-75• Make sure you wipe the iron tip on the wet

sponge every time you solder something• Components should be flush to the board• Demos will be done in the lab. • Ask us for help if you need it. Hint: You

will.

moreHELP

• You CAN destroy components and/or parts of the board

• You ARE easily burned. Be careful.• Highly recommended set of tutorials +

videos:

http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=96

testandDEBUG

• The schematic and BOM are on our website. This presentation will be on our website.

• You should check our website.• It probably won’t work the first

time you turn it on. This is normal.

thereFORE

• Test all power inputs before soldering chips onto the boards.

• Flux remover is your best friend. Flux is a flowing liquid residue from soldering. It’s conductive. Enough said.

• Pay close attention to component polarity where applicable. This is how chips explode.

generalADVICE

• Divide up tasks. Work concurrently.• You don’t need the lab to program or

sketch drawings.• It’s on YOU to ensure work gets done.• Remember to allocate time for testing.

Very few things in engineering work the first time. Especially robots.

questions?

• Feel free to ask me or any one else in the lab for help

• If you’re curious about what a particular circuit does, ask me and I’ll do my best to explain it

buildTIME

• Starts now.• TWO of you per team (max.) should come

with me to the soldering session.• You also have software to write and a

chassis to design and build