File:Team22 code.c

2008-03-19T22:54:20Z

2008-03-19T21:44:15Z

BrianLesperance: /* Vibratory Clock */

'''[[ME 333 end of course schedule]]'''

__TOC__

== ME 333 Final Projects 2008 ==

=== [[IR Tracker]] ===

[[Image:IR_Tracker_Main.jpg|right|thumb|200px]]

The IR Tracker (aka "Spot") is a device that follows a moving infrared light. It continuously detects the position of an infrared emitter in two axises, and then tracks the emitter with a laser.

 

=== [[Robot Snake]] ===
[[Image:HLSSnakeMain.jpg|right|thumb|200px]]

A wirelessly controlled robotic snake which uses a traveling sine wave and servo motors to mimic serpentine motion. The snake is capable of going forward, left, right and in reverse.

 

=== [[Programmable Stiffness Joint]] ===

[[Image:SteelToePic.jpg|thumb|200px|The 'Steel Toe' programmable stiffness joint|right]]

The Programmable Stiffness Joint varies rotational stiffness as desired by the user. It is the first step in modeling the mechanical impedance of the human ankle joint (both stiffness and damping) for the purpose of determining the respective breakdown of the two properties over the gait cycle.

 

=== [[Magnetic based sample purification]] ===

 

=== [[Continuously Variable Transmission]] ===

[[image:CVT_setup1.jpg|thumb|200px]]

A continuously variable tramsission is intended to provide a transition from low to high gear ratios while keeping the engine input running at the max efficient speed. It is achieved by a system of variable radius pulleys and a v-belt.

 

=== [[Granular Flow Rotating Sphere]] ===

This device will be used to study the granular flow of particles within a rotating sphere. The sphere is filled with grains of varying size and then rotated about two different axes according to a series of position and angular velocity inputs.

 

=== [[Vibratory Clock]] ===

[[Image:Vibratory_Clock.jpg|right|thumb|Vibratory Clock|200px]]

The Vibratory Clock allows a small object to act as an hour "hand" on a horizontal circular platform that is actuated from underneath by three speakers. The object slides around the circular platform, impelled by friction forces due to the vibration. [http://www.youtube.com/watch?v=PV9utFL5J6w Check it out!]

 

=== [[WiiMouse]] ===

[[Image:HPIM1027.jpg|right|thumb|200px]]

The WiiMouse is a handheld remote that can be used to move a cursor on a windows-based PC, via accelerometer input captured through device movement.

 

=== [[Intelligent Oscillation Controller]] ===

This device "learns" a forcing function that is applied to a spring and mass system to match an arbitrary, periodic acceleration profile.

=== [[Baseball]] ===

[[Image:Baseball_Playfield.jpg|right|thumb|200px]]

An interactive baseball game inspired by pinball, featuring pitching, batting, light up bases and a scoreboard to keep track of the game.

Vibratory Clock

2008-03-19T21:28:20Z

BrianLesperance: /* Electrical Design */

File:Team22 circuit.jpg

2008-03-19T21:16:55Z

BrianLesperance: This is the circuit diagram for the Vibratory Clock. Channels 1, 2, and 3 go into Left 1, Right 1, and Left 2 channels on the amplifier respectively.

This is the circuit diagram for the Vibratory Clock. Channels 1, 2, and 3 go into Left 1, Right 1, and Left 2 channels on the amplifier respectively.

2008-02-06T09:58:14Z

BrianLesperance: /* Circuit */

== Overview ==
Using serial communication, two PICs can easily communicate with one another. A basic extension, IR communication can easily be set up for a microcontroller (PIC) by using an IR Encoder/Decoder (Endec) and an IR Transceiver. The endec and transceiver used in this example support Serial IR (SIR) data rate, ranging from 9.6 kpbs - 115.2 kpbs. The typical range of the transceiver is nominally between 2in to 2ft, extending upwards of 12ft. The UART, endec, and transceiver used all support bidirectional use. However, due to the fact that when a transceiver is transmitting, it essentially blinds its receiver and therefore cannot attain true full-duplex communication, only half-duplex, taking turns transmitting and receiving.

When transmitting, the PIC sends the serial format data to the endec, who receives this serial data and encodes (or modulates) it bit by bit. This encoded data is then output as electrical pulses to the transceiver. The transceiver will then convert these electrical pulses to IR light pulses. On the receiving side, the transceiver receives IR light pulses (data), which are outputted as electrical pulses. The endec decodes (or demodulates) these electrical pulses, with the data then being transmitted by the endec UART back to the receiving PIC. This modulation/demodulation method is performed in accordance with the IrDA standard.

[[Image:copper_clad_board.jpg|thumb|400px|Copper-Clad Board]]

Both the PIC and the endec used in this example were DIP packages, making them easy to prototype and inspect. The transceiver, however, was a surface mount chip with an uncommon pin configuration (.95 mm pitch), requiring a different approach. We initially attempted to etch a [http://www.radioshack.com/sm-2-sided-copper-clad-pc-board--pi-2102495.html copper-clad board] for our circuit (see image). Another possible solution for our transceiver is to use a [http://www.schmartboard.com/index.asp?page=products_so&id=54 SchmartBoard]. These boards are more general and prefabricated for use with surface mount ICs (with a particular pitch or pin seperation). Both solutions will allow for connections to a solderless breadboard.

== Circuit ==
The Circuit Diagram shows the layout of the PIC, Encoder/Decoder, and IR Transceiver combination. Two of these set-ups are needed in order to have two independent circuits: one to transmit and one to receive data. The specifications of the circuit are as follows:

[[Image:IR_circuit.jpg|thumb|600px|Circuit Diagram]]

===Electrical Characteristics===
''µController (PIC18F4520)''
*VDD = 5.0V
*C1 = 1µF
**Pin 11 or 32 can be used for VDD
**Pin 12 or 31 can be used for GND

''IR Encoder/Decoder (MCP2122-E/P)''
*VDD = 5.0V (1.8V-5.5V)
*CBYP = 0.01µF

''IR Transceiver (TFDU4300-TR1)''
*Vcc1 = 5.0V (2.4V-5.5V)
*Vcc2 = 5.0V (-0.3V-6.0V)
*Vlogic = 5.0V (1.5V-5.5V)
*R2 = 47Ω
*C2 = 0.1µF

The links to the data sheets for the Encoder/Decoder and the IR Transceiver can be found in the External Links sections.

*PIC interfaces serially with EnDec
*EnDec connected to transceiver through a transmit pin, a receive pin, and a Vlogic pin?
*Transceiver manufactured by Vishay Semiconductors
**Part # TFDU4300
*EnDec manufactured by Microchip
**Part # MCP2122

=== Surface Mount Prototyping ===
*Transceiver lead pitch = 1.2mm/0.95mm/0.50mm/0.45mm?
*Multiple options for installation
**Schmart board
**Digikey board (need to find)
**Copper-clad board etching
**Funky pin adapter thing Prof. Peshkin gave us
**Funky adapter thing #2 Prof. Peshkin gave us

=== Limitations ===
*Transceiver cannot simultaneously transmit and receive

== Code ==

Example code for a simple IR communication circuit w/o the use of a transceiver:

/*
ircomm.c Jennifer Breger, Brian Lesperance, Dan Pinkawa 2008-02-05
Using the PIC's built-in UART, a counter continually is sent to one IR encoder/decoder. Then
the first IR encoder/decoder feeds its TXIR to the RXIR of a second IR encoder/decoder. The
second IR encoder/decoder then transmits back to the PIC what it is receiving. When the
transceiver circuit is properly mount and inserted into the circuit, this code can be adapted
for half-duplex communication w/ another IR communications circuit.
*/

#include <18f4520.h>
#fuses HS,NOLVP,NOWDT,NOPROTECT
#use delay (clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, stream=com_a) // Initializes the UART to 9600 bps
// (up to 115,200 bps)

// timed_getc() checks whether data is ready to be read. If it's not the function returns a null
// character. If you simply use getc(), the PIC might get slowed up if the data isn't ready right
// away.
char timed_getc(void){
long timeout;
int timeout_error = FALSE;
timeout = 0;
while(!kbhit() && (++timeout<50000))
delay_us(10);
if (kbhit())
return(getc());
else {
timeout_error = TRUE;
return(0);
}
}

// Main program
void main(void){
int i;
char rx;

setup_timer_2(T2_DIV_BY_1, 32, 16); // Provides a 151.3 kHz clock for the Encoder/Decoder, in
setup_ccp1(CCP_PWM); // order for it to know the baud rate of the UART. Should be
set_pwm1_duty(16); // closer to 16 * 9600 = 153.6 kHz but the error is tolerable

while(TRUE){
for(i=0;i<16;i++){ // Counts up from 0 to 15 and transmits to the first Encoder/Decoder.
putc(i); // Listens to the second Encoder/Decoder, which is simply the original
rx = timed_getc(); // message from the PIC, and displays the value on the LEDs/Port D.
output_d((int8) rx);
delay_ms(1000);
}
}
}

= External Links and Further Reading =
*[http://ww1.microchip.com/downloads/en/DeviceDoc/21894c.pdf IR Transceiver Data Sheet]
*[http://ww1.microchip.com/downloads/en/DeviceDoc/21894c.pdf IR Encoder/Decoder Data Sheet]
*[http://www.schmartboard.com/ Schmartboard (Prototyping boards for SMT)]

== Relevant Technical Articles ==

*[http://en.wikipedia.org/wiki/Infrared_communication#Communications| Infrared communication]
*[http://en.wikipedia.org/wiki/Serial_communications| Serial communication]
*[http://en.wikipedia.org/wiki/Surface_mount| Surface mount technology]
*[http://en.wikipedia.org/wiki/UART| UART]