Designing with components II

Fall 2009/R Fall 2013

Overview

Possible Components

DC/DC Converters

Adjustable boost regulator can generate an output voltage as high as 25 V from an input voltage as low as 1.5 V.

A trimmer potentiometer lets you set the boost regulator’s output voltage to a value between 4 and 25 V.

Switching step-down voltage regulator takes an input voltage between 4.5 V and 42 V and efficiently reduces it to a lower, user-adjustable voltage. It has a output voltage range of 2.5 V to 7.5 V and a maximum output current of 300mA.

http://www.pololu.com/

Components: 28015

Parallax's new PING)))™ ultrasonic sensor provides a very low-cost and easy method of distance measurement. This sensor is perfect for any number of applications that require you to perform measurements between moving or stationary objects.

The PING)))™ sensor measures distance using sonar; an ultrasonic (well above human hearing) pulse is transmitted from the unit and distance-to-target is determined by measuring the time required for the echo return.

http://www.parallax.com/product/2801528015.pdf

Components: 28015

FeaturesSupply Voltage: 5 VDCSupply Current: 30 mA typ; 35 mA maxRange: 3cm to3 m( 1.2in to 3.3yrds)Input Trigger: positive TTL pulse, 2 us mm, 5 us typ.Echo Pulse: positive TTL pulse, 115 us to 18.5 mSEcho Hold-off: 750 us from fall of Trigger pulse Burst Frequency: 40 kHz for 200 usBurst Indicator LED shows sensor activityDelay before next measurement: 200 usSize: 22 mm H x 46 mm W x 16 mm D (0.84 in x 1.8 in x 0.6 in

Components: 28015

Components: 28015

Components: 28015

Components: GP2D120

Sharp GP2D120 Analog Distance SensorLess influence on the color of reflective objects, reflectivityLine-up of distance output/distance judgment type

• Distance output type (analog voltage) GP2D120 Detecting distance 4 to 30cm

Recommended: buy the interconnect cableGP2D120.pdf(Buy New Versions)

Components: GP2D120

Components: GP2D120

14,000 lx

http://www.acroname.com/robotics/info/articles/sharp/sharp.html

These new rangers all use triangulation and a small linear CCD array to compute the distance and/or presence of objects in the field of view.  The basic idea is this: a pulse of IR light is emitted by the emitter.  This light travels out in the field of view and either hits an object or just keeps on going.  In the case of no object, the light is never reflected and the reading shows no object.  If the light reflects off an object, it returns to the detector and creates a triangle between the point of reflection, the emitter, and the detector. 

Components: GP2D12

Sharp GP2D12 Analog Distance SensorFeatures

Less influence on the color of reflective objects, reflectivityLine-up of distance output/distance judgment type

• Distance output type (analog voltage) GP2DI 2 Detecting distance 10 to 80cm

• Distance judgment type: GP2DI5 Judgment distance 24cm. Adjustable within the range of 10 to 80cm) 3. External control circuit is unnecessary

GP2D12.pdf

Components: GP2D12

80 cm

2.4 V

Components: GP2D12

14,000 lx

http://www.robotroom.com/HBridge.html

This is just an example, we prefer to use the TC4422 in the T0-220 package which has higher Current capability but is single channel.

Components: TC4421/TC4422

PWM

In the graphic, the green lines represent a regular time period. This duration or period is the inverse of the PWM frequency. In other words, with Arduino's PWM frequency at about 500Hz, the green lines would measure 2 milliseconds each.

A call to analogWrite() is on a scale of 0 - 255, such that analogWrite(255) requests a 100% duty cycle (always on), and analogWrite(127) is a 50% duty cycle (on half the time) for example.

analogWrite(pin, value)

Components: TC4421/TC4422

Features High Peak Output Current: 9A Wide Input Supply Voltage Operating Range: 4.5V to 18V High Continuous Output Current: 2A Max Fast Rise and Fall Times:

30 ns with 4,700 pF Load 180 ns with 47,000 pF Load

Short Propagation Delays: 30 ns (typ) Low Supply Current:

With Logic ‘1’ Input: 200 µA (typ) With Logic ‘0’ Input: 55 µA (typ)

Low Output Impedance: 1.4 (typ) Latch-Up Protected: Will Withstand 1.5A Output Reverse Current Input Will Withstand Negative Inputs Up To 5V Pin-Compatible with the TC4420/TC4429 6A MOSFET Driver Space-saving 8-Pin 6x5 DFN Package http://www.microchip.com/stellent/idcplg?

IdcService=SS_GET_PAGE&nodeId=1335&dDocName=en010665

Components: TC4421/TC4422

H Bridge ST L298http://www.st.com/stonline/products/literature/ds/1773.pdf

Position Determination

Stock#: 605-0005Melexis 90217 Hall-Effect SensorPrice:  $4.95

3/8 diameter, 1/8 thick NdFeB plate magnet

Position Determination

1. Hamamatsu P5587 Wheel Encoder Modules + 30 Spoke Wheel 1.5” Encoder Disks or similar

http://www.pololu.com/catalog/product/1440

This is the motor and encoder portion the 37D mm metal gearmotors with 64 CPR (cycles per revolution) encoders.

Position Determination

http://www.labbookpages.co.uk/circuits/wheelEncoder.html

Position Determination

ACE 128 Absolute Encoder

http://www.newark.com/jsp/Passives/Encoders/BOURNS/EAW0D-B24-AE0128/displayProduct.jsp?sku=04B9184

$10.75

Position Determination

Incremental EncoderECL1J-B24-BC0024 —

BOURNS http://www.newark.com/

jsp/Passives/Encoders/BOURNS/ECL1J-B24-BC0024/displayProduct.jsp?sku=04B9197

$4.26

DC Motors

“DC motors are widely used, inexpensive, small and powerful for their size.

Reduction gearboxes are often required to reduce the speed and increase the torque output of the motor.

Accurate control over the axial rotation of these motors requires additional components and algorithms.

Compared to stepper motor they offer smooth control and high levels of acceleration.

Stepper Motor Driver. ON MC3479

Stepper Motors http://www.cs.uiowa.edu/~jones/step/

Variable Reluctance

Unipolar

Winding 1 1001001001001001001001001

Winding 2 0100100100100100100100100

Winding 3 0010010010010010010010010

Winding 1a 1000100010001000100010001 Winding 1b 0010001000100010001000100 Winding 2a 0100010001000100010001000 Winding 2b 0001000100010001000100010

Stepper Motors http://www.cs.uiowa.edu/~jones/step/

Bipolar Bifilar

Terminal 1a +---+---+---+--- ++--++--++--++--

Terminal 1b --+---+---+---+- --++--++--++--++

Terminal 2a -+---+---+---+-- -++--++--++--++-

Terminal 2b ---+---+---+---+ +--++--++--++--+

Stepper Torque

Stepper motors have the greatest torque at slower speeds and less torque as the motor speeds up.

If the motors are started at full speed they will not move the mouse at all, the motors will simply "twitch" and the rotor will not rotate to the next position.

In order to move the mouse, the motors must be accelerated to top speed. Likewise, in order to stop the mouse, the motors must be slowed down. A graph of the stepper's speed would look like this:

http://www.micromouseinfo.com/introduction/steppers.html

Digital Potentiometer

They don’t have a DIP package for the up/down versions.

I would suggest using the SOIC package and soldering some cables to the IC

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1335&dDocName=en025082

Components: Memsic 2125 Dual-axis Accelerometer

The Memsic 2125 is a low cost, dual-axis thermal accelerometer capable of measuring dynamic acceleration (vibration) and static acceleration (gravity) with a range of ±2 g

Key Features of the Memsic 2125: Measure 0 to ±2 g on either axis; less than 1 mg resolution Fully temperature compensated over 0° to 70° C range Simple, pulse output of g-force for X and Y axis Analog output of temperature (TOut pin) Low current operation: less than 4 mA at 5 vdc

Components: Memsic 2125 Dual-axis Accelerometer

How It Works Internally, the Memsic 2125 contains

a small heater. This heater warms a "bubble" of air within the device. When gravitational forces act on this bubble it moves. This movement is detected by very sensitive thermopiles (temperature sensors) and the onboard electronics convert the bubble position [relative to g-forces] into pulse outputs for the X and Y axis.

The pulse outputs from the Memsic 2125 are set to a 50% duty cycle at 0 g. The duty cycle changes in proportion to acceleration and can be directly measured by the BASIC Stamp. Figure 2 shows the duty cycle output from the Memsic 2125 and the formula for calculating g force.

CMUCAM

http://www.cmucam.org/

http://www.youtube.com/watch?v=kWG2EbhZUgchttp://www.youtube.com/watch?v=IXy2F4Zv60M

UART2B-EEL

unsigned adcRes; char txt[6];

void main() { int i; PORTB = 0x0000; TRISB.F1 = 1; // set pin as input - needed for ADC to work

Uart1_Init(19200);

while (1) { adcRes = Adc_Read(1); // Read ADC channel 1 WordToStr(adcRes, txt); // Convert ADC value to text i=0; while (txt[i]) { Uart1_Write_Char(txt[i]); // Send text to UART one character at a time i=i+1; Delay_ms(1000); } } }//~!

CAN

Components: Parallax (Futaba) Continuous Rotation Servo: 900-00008

Technical Specifications Power 6vdc max Average Speed 60 rpm, Note: with 5vdc and no torque Weight 45.0 grams/1.59oz Torque 3.40 kg-cm/47oz-in Size mm (L x W x H), 40.5x20.0x38.0 Size in (L x W x H), 1.60x.79x1.50 Manual adjustment port www.parallax.com continuous rotation

$6.95 http://www.parallax.com/detail.asp?product_id=900-00008 crservo.pdf

Components: Parallax (Futaba) Continuous Rotation Servo: 900-00008

Additional Resources

http://www.cs.cmu.edu/~cmucam/http://www.pololu.com/ (Check gear boxes)http://www.vexlabs.com/http://www.kitsusa.net/phpstore/index.php (Check

Motors and Robot Arm)

Overview

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