Basics on Tools, Power, and

Communication

Prof. Rohan MunasingheDepartment of Electronic and Telecommunication EngineeringFaculty of Engineering

University of Moratuwa 10400

Electronic Tools

50W soldering station PCB Holder Third Hand (for soldering)

60% Sn (Tin), 40% Pb (Lead), rosin-core solder (wash your hands after soldering) Desoldering sucker

Electronic Tools

Tip Tinner(removes oxide)

Wire cutter

Twizeer Wire stripper

Power Supplies

• AC to DC conversion

Power Supplies• Voltage Regulation using Zener Diode

• Voltage Regulation Using Regulator IC For a stabile

transient

responseresponse

Reduce ripple

• Using unregulated power adapters

Power Supply

LiPo Batteries

• Voltage and Capacity

• One cell = 3.7V / 2200mHh

– 2S: two series cells (7.4V / 2200mHh)

– 3S: three series cells (11.1V/2200mAh).– 3S: three series cells (11.1V/2200mAh).

• 2P means that there are two groups of cells wired in parallel

to increase capacity without increasing voltage.

– 3S2P: two parallel packs of three cells (11.1V/4400mAh).

LiPo Batteries• Current Rating (C rating) : Example 2200mAh battery with

25C continuous, 35C "climb outs" and 50C max bursts.

– 25C pack would be 25 x 2200/1000 = 50 Amps (continuous).

– This battery can supply 50Amps continuously, 77Amps for a short period and a max short burst of 110Amps.period and a max short burst of 110Amps.

• Special balance Charger to be used.

• Store LiPo in a “LiPo safe” bag (recommended).

Wire ties and connectors• Firm electrical connections

– No hand wound connections

– No open battery terminal wires

(use insulated sockets)

• Tie up wires to mobile platform

neatly using wire ties. Bundle

them whenever possible

Digital Communication• UART : Universal Asynchronous Receiver Transmitter

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Serial transmission

Device 1 Device 2

1 byte 1 byte

UART

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UART

RS-232

RS-422

RS-485

etc

RS-232

RS-422

RS-485

etc

Serial transmission

etc etc

RS232 Serial Standard

• Pinout

1. DCD-data carrier detect

2. Receive Data

3. Transmit data

4. Data terminal ready

5. GND

6. Data set ready

7. Request to send

8. Clear to send

9. Ring indicator

RS232 Data Format

• Data rate, parity (optional), number of stop bits are configurable

-12-5

• Non return to Zero Level (NRTZL) line encoding

-5

+5+12

USB Interface

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Device complies with USB standards

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USB driver passed Windows Hardware Quality Labs Test

(WHQLT)

USB Interface

Maximum 5 hubs in series

USB Cable

• 5m length, use hubs to extend

High CMRR

• 5m length, use hubs to extend

further

• 3.3V, non return to zero

inverted (NRTZI) bit encoding

(serial transmission)