树莓派-PS2操作杆实验.md

树莓派-PS2操作杆实验

原理图

接线图

树莓派管脚图

代码

C

#include <stdio.h>
#include <wiringPi.h>
#include <pcf8591.h>

#define PCF       120
#define uchar	unsigned char

int AIN0 = PCF + 0;
int AIN1 = PCF + 1;
int AIN2 = PCF + 2;

char *state[6] = {"home", "up", "down", "left", "right", "pressed"};

int direction(){
	int x, y, b;
	int tmp;
	x = analogRead(AIN1);
	y = analogRead(AIN0);
	b = analogRead(AIN2);
	if (y == 0)
		tmp = 1;		// up
	if (y == 255)
		tmp = 2;		// down
	
	if (x == 255)
		tmp = 3;		// left
	if (x == 0)
		tmp = 4;		// right

	if (b == 0)
		tmp = 5;		// button preesd
	if (x-125<15 && x-125>-15 && y-125<15 && y-125>-15 && b == 255)
		tmp = 0;		// home position
	
	return tmp;
}

int main (void)
{
	int tmp;
	int status = 0;
	wiringPiSetup ();
	// Setup pcf8591 on base pin 120, and address 0x48
	pcf8591Setup (PCF, 0x48);
	while(1) // loop forever
	{
		tmp = direction();
		if (tmp != status)
		{
			printf("%s\n", state[tmp]);
			status = tmp;
		}
	}
	return 0 ;
}

编译命令：gcc joystick_PS2.c -o joystick_PS2 -lwiringPi

Python

#!/usr/bin/env python
#------------------------------------------------------
#
#		This is a program for JoystickPS2 Module.
#
#		This program depend on PCF8591 ADC chip. Follow 
#	the instruction book to connect the module and 
#	ADC0832 to your Raspberry Pi.
#
#------------------------------------------------------
import PCF8591 as ADC 
import time

def setup():
	ADC.setup(0x48)					# Setup PCF8591
	global state

def direction():	#get joystick result
	state = ['home', 'up', 'down', 'left', 'right', 'pressed']
	i = 0

	if ADC.read(0) <= 5:
		i = 1		#up
	if ADC.read(0) >= 250:
		i = 2		#down

	if ADC.read(1) >= 250:
		i = 3		#left
	if ADC.read(1) <= 5:
		i = 4		#right

	if ADC.read(2) == 0:
		i = 5		# Button pressed

	if ADC.read(0) - 125 < 15 and ADC.read(0) - 125 > -15	and ADC.read(1) - 125 < 15 and ADC.read(1) - 125 > -15 and ADC.read(2) == 255:
		i = 0
	
	return state[i]

def loop():
	status = ''
	while True:
		tmp = direction()
		if tmp != None and tmp != status:
			print tmp
			status = tmp

def destroy():
	pass

if __name__ == '__main__':		# Program start from here
	setup()
	try:
		loop()
	except KeyboardInterrupt:  	# When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
		destroy()

#!/usr/bin/env python
#------------------------------------------------------
#
#		This is a program for PCF8591 Module.
#
#		Warnng! The Analog input MUST NOT be over 3.3V!
#    
#		In this script, we use a poteniometer for analog
#   input, and a LED on AO for analog output.
#
#		you can import this script to another by:
#	import PCF8591 as ADC
#	
#	ADC.Setup(Address)  # Check it by sudo i2cdetect -y -1
#	ADC.read(channal)	# Channal range from 0 to 3
#	ADC.write(Value)	# Value range from 0 to 255		
#
#------------------------------------------------------
import smbus
import time

# for RPI version 1, use "bus = smbus.SMBus(0)"
bus = smbus.SMBus(1)

#check your PCF8591 address by type in 'sudo i2cdetect -y -1' in terminal.
def setup(Addr):
	global address
	address = Addr

def read(chn): #channel
	if chn == 0:
		bus.write_byte(address,0x40)
	if chn == 1:
		bus.write_byte(address,0x41)
	if chn == 2:
		bus.write_byte(address,0x42)
	if chn == 3:
		bus.write_byte(address,0x43)
	bus.read_byte(address) # dummy read to start conversion
	return bus.read_byte(address)

def write(val):
	temp = val # move string value to temp
	temp = int(temp) # change string to integer
	# print temp to see on terminal else comment out
	bus.write_byte_data(address, 0x40, temp)

if __name__ == "__main__":
	setup(0x48)
	while True:
		print 'AIN0 = ', read(0)
		print 'AIN1 = ', read(1)
		tmp = read(0)
		tmp = tmp*(255-125)/255+125 # LED won't light up below 125, so convert '0-255' to '125-255'
		write(tmp)
#		time.sleep(0.3)