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‘ Physical Computing ’ category archive
Jan
11
Mar
04
Photocell + 8×8 LED Matrix
This is an example of using 2 photocells and a variable resistor as analog inputs to control 8×8 LED Matrix with PIC18F452, UDN2981, and ULN2803. The input values of the two photocells are compared. When the values are the same, LED lights up randomly within the entire board. Depending on how much darker a photocell is compared to the other, LED lights up within the range that is more focused towards a corner. The variable resistor controls how fast the LEDs blink. This is how the board was set up:
The following is the code:
DEFINE LOADER_USED 1
DEFINE OSC 20
INCLUDE “modedefs.bas”
DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 20
ADCON1 = %10000010
trisb =%00000000
trisd =%00000000
trisa =%11111111
trisc =%10000000
an0 var word
an1 var word
an2 var word
an0b var byte
an1b var byte
an2b var byte
portb = 0
portd = 0
rand_max var byte
rand_min var byte
random_word var word
randomdig var byte
main:
GOSUB getadc
IF an1b < an2b THEN
rand_max=an1b
rand_min=0
ENDIF
IF an1b > an2b THEN
rand_max=7
rand_min=7-an2b
ENDIF
IF an2b = an1b THEN
rand_max=7
rand_min=0
ENDIF
GOSUB generate_Random
portb = 1<<randomdig
GOSUB generate_Random
portd = 1<<randomdig
PAUSE 10*an0b
gosub bd_off
PAUSE 1*an0b
GOTO main
bd_off:
portb=0 : portd=0
RETURN
getadc:
ADCIN 0,an0
ADCIN 1,an1
ADCIN 2,an2
an0b = (an0*8)>>10
an1b = (an1*8)>>10
an2b = (an2*8)>>10
RETURN
generate_random:
RANDOM random_word
randomdig = random_word DIG 1
IF randomdig > rand_max THEN GOTO generate_random
IF randomdig < rand_min THEN GOTO generate_random
RETURN
Feb
22
Analog / Digital Input, Output
This is an example of using 2 variable resistors as analog inputs and a switch as a digital input to control 8 LEDs with a PIC18F452 chip. Variable resistor 1 is used to control which LEDs light up. The second variable resistor controls how fast the LEDs blink. The switch decides whether the LEDs blink or not. MAX232CPE is used to allow serial communication with a computer. PICBASIC was used to program the chip. This is how the board was set up:
The following is the code:
DEFINE LOADER_USED 1
DEFINE OSC 20
INCLUDE “modedefs.bas”
DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 20
ADCON1 = %10000010
TRISA = %11111111
TRISB = %00000000
TRISC = %10001000
adc VAR WORD
adcbyte VAR BYTE
SPEED VAR WORD
SPEEDbyte VAR BYTE
SWITCH VAR PORTC.4
main:
IF SWITCH = 1 THEN
ADCIN 0, adc
adcbyte = adc/140
ADCIN 1, SPEED
SPEEDbyte = SPEED/140
PORTB = %00000001 << adcbyte
PAUSE 100*SPEEDbyte
PORTB = 0
PAUSE 100*SPEEDbyte
ELSE
ADCIN 0, adc
adcbyte = adc/140
PORTB = %00000001 << adcbyte
ENDIF
GOTO main
Jan
29
Jan
23
Physical Computing – Current Amplification
Today was my first day at a physical computing workshop run by Jin-Yo Mok (http://www.geneo.net). I’m starting from the very basics to understand how every single piece operates at the most fundamental level. The breadboard in the image shows the simplest setup of current amplification using an NPN transistor (2N2222). Hopefully, I’ll be able to design custom circuit boards in the future as I become more comfortable with all these volts and currents :)
Nov
25
the experiment begins
I’ve been craving to learn how to utilize sensors, actuators, controller boards, and osc to build some interactive environments (post-robotic-ecologies-trauma). Suspecting that most of these products would be made in China anyways and that they’d be quite cheap, my friend and I have started to explore the world of Zhong Guan Cun. We ran into a few stores that specialize in making sensors and circuit boards. We spent about $10. We now have about a hundred LEDs, an infrared sensor, a photosensor, and etc -_-b
It wasn’t easy getting a controller board that we could burn customized program on to. Luckily, we got in touch with an IBM engineer that builds Arduino boards for hobby. So, now the experiment begins :)
