Blinky and Button examples using Python
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==Blinky Example== | ==Blinky Example== | ||
| + | User LED is connected to GPIO PA30. An interface for the user LED is created in the kernel by adding the following code in board-electrum-100.c | ||
| + | /* | ||
| + | * LEDs | ||
| + | */ | ||
| + | static struct gpio_led ek_leds[] = { | ||
| + | { /* led1, yellow */ | ||
| + | .name = "ds1", | ||
| + | .gpio = AT91_PIN_PA25, | ||
| + | .default_trigger = "heartbeat", | ||
| + | }, | ||
| + | { /* led2, green */ | ||
| + | .name = "ds2", | ||
| + | .gpio = AT91_PIN_PA30, | ||
| + | //.active_low = 1, | ||
| + | .default_trigger = "none", | ||
| + | } | ||
| + | }; | ||
| + | |||
| + | And add the following lines in ek_board_init | ||
| + | /* LEDs */ | ||
| + | at91_gpio_leds(ek_leds, ARRAY_SIZE(ek_leds)); | ||
| + | |||
| + | Python scrip for Blinky Example: | ||
import sys | import sys | ||
import time | import time | ||
Revision as of 17:11, 3 August 2010
Contents |
Examples using Python
The following application note covers the use of Electrum100's peripherals using Python. SYSFS method has been used to access the GPIO's. To create the interfaces for GPIO's under /sys/class/gpio/*, the following configuration has to be enabled in the board configuration file
CONFIG_GPIO_SYSFS=Y
Blinky Example
User LED is connected to GPIO PA30. An interface for the user LED is created in the kernel by adding the following code in board-electrum-100.c
/*
* LEDs
*/
static struct gpio_led ek_leds[] = {
{ /* led1, yellow */
.name = "ds1",
.gpio = AT91_PIN_PA25,
.default_trigger = "heartbeat",
},
{ /* led2, green */
.name = "ds2",
.gpio = AT91_PIN_PA30,
//.active_low = 1,
.default_trigger = "none",
}
};
And add the following lines in ek_board_init
/* LEDs */ at91_gpio_leds(ek_leds, ARRAY_SIZE(ek_leds));
Python scrip for Blinky Example:
import sys
import time
print "Blinking User LED"
print "Enter CTRL+C to exit"
def ledon():
value = open("/sys/class/leds/ds2/brightness","w")
value.write(str(1))
value.close()
def ledoff():
value = open("/sys/class/leds/ds2/brightness","w")
value.write(str(0))
value.close()
while True:
ledon()
time.sleep(.5)
ledoff()
time.sleep(.5)
Button Example
import sys
import time
print "Button Example"
print "Press CTRL + C to exit"
def pins_export():
try:
pin1export = open("/sys/class/gpio/export","w")
pin1export.write(str(63))
pin1export.close()
except IOError:
print "INFO: GPIO 63 already Exists, skipping export gpio"
def read_button():
fp1 = open("/sys/class/gpio/gpio63/value","r")
value = fp1.read()
return value
fp1.close()
def write_led(value):
fp2 = open("/sys/class/leds/ds2/brightness","w")
fp2.write(str(value))
fp2.close()
pins_export()
while True:
button_value = read_button()
write_led(button_value)