Title: [fireflyP] Python For Firefly Port release [Print This Page] Author: zhansb Time: 7/23/2016 11:59 Title: [fireflyP] Python For Firefly Port release Last edited by zhansb In 7/23/2016 11:59 Editor
fireflyP is designed for using devices port on firefly or other similar platforms.It can support RK3288 now.
Like GPIO, PWM, SPI and so on.
NOTE: fireflyP is still in development. if you find something wrong, please let me know, and if you fix bugs, it is nice to give me 'Pull requests'
install python modules(python can be python2 or python3):
$ sudo python setup.py install
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Usage
GPIO and PWM control regs directly by devmem in fireflyP, and independent of kernel space.
The devmem source is modifed from pydevmem(Thanks to Kyle).
You need root privilege to execute it! Gpio Interface:
init()
Init GPIO function
implement it before using Gpio
get_level(self)
Returns the level of the pin for input direction
or return setting of the DR register for output gpios.
set_dir(self, dir)
set GPIO direction
:dir: refer to GpioDir
set_drv(self, drv)
set GPIO drv
:drv: refer to GpioDrv
set_level(self, level)
set GPIO output signal
:level: refer to GpioLevel
set_mux(self, mux)
set GPIO mux
:mux: refer to GpioMux
set_pull(self, pull)
set GPIO pull
:pull: refer to GpioPull
Example for turn on/off the yellow led on firefly-rk3288:
$sudo python
>>> from fireflyP import Gpio
>>> Gpio.init()
>>> LED_YELLOW="GPIO8A2"
>>> led_yellow=Gpio(LED_YELLOW)
>>> led_yellow.set_dir(Gpio.OUTPUT) #set_dir have contained set_mux(GpioMux.MUX_GPIO)
>>> led_yellow.set_level(Gpio.LOW) #turn on the yellow led
>>> led_yellow.set_level(Gpio.HIGH) #turn off the yellow led
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or you can refer to demo/gpio_test.py
Pwm Interface:
init()
Init PWM function
implement it before using Pwm
get_counter(self)
Get PWM counter
set_config(self, period, duty, config=10)
set PWM period and duty.
:period: ns
:duty: ns
:config: set PWMx_CTRL value except PWMx_CTRL.scale
set_counter(self, counter)
set PWM counter
start(self)
Start PWM
stop(self)
Stop PWM
Example for config pwm1(freq=1MHz,duty=50%):
$sudo python
>>> from fireflyP import Gpio
>>> from fireflyP import Pwm
>>> Gpio.init()
>>> g7a1=Gpio('GPIO7A1')
>>> g7a1.set_mux(1) #set GPIO7A1 mux to pwm1
>>> Pwm.init()
>>> pwm=Pwm('PWM1')
>>> pwm.set_config(1000,500)
>>> pwm.start()
>>> pwm.stop()
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or you can refer to demo/pwm_test.py
Spi
Spi in fireflyP is depend on spidev,make sure your kernel support spidev(like this patch) or you can down the ready-made firmware([Google drive],[Baidu]).
The Spi source is modifed from python-spi (Thanks to Thomas).
Interface:
read(self, length, speed=0, bits_per_word=0, delay=0)
Perform half-duplex Spi read as a binary string
Args:
length: Integer count of words to read
speed: Optional temporary bitrate override in Hz. 0 (default)
uses existing spidev speed setting.
bits_per_word: Optional temporary bits_per_word override. 0
(default) will use the current bits_per_word setting.
delay: Optional delay in usecs between sending the last bit and
deselecting the chip select line. 0 (default) for no delay.
Returns:
List of words read from device
transfer(self, data, speed=0, bits_per_word=0, delay=0)
Perform full-duplex Spi transfer
Args:
data: List of words to transmit
speed: Optional temporary bitrate override in Hz. 0 (default)
uses existing spidev speed setting.
bits_per_word: Optional temporary bits_per_word override. 0
(default) will use the current bits_per_word setting.
delay: Optional delay in usecs between sending the last bit and
deselecting the chip select line. 0 (default) for no delay.
Returns:
List of words read from Spi bus during transfer
Args:
data: List of words to write
speed: Optional temporary bitrate override in Hz. 0 (default)
uses existing spidev speed setting.
bits_per_word: Optional temporary bits_per_word override. 0
(default) will use the current bits_per_word setting.
delay: Optional delay in usecs between sending the last bit and
deselecting the chip select line. 0 (default) for no delay.
Example for config spi0:
$sudo python
>>> from fireflyP import Spi
>>> spi = Spi('/dev/spidev0.0')
>>> spi.mode = Spi.MODE_3
>>> spi.bits_per_word = 8
>>> spi.speed = 1000*1000
>>> received = spi.transfer([0x11, 0x22, 0xFF])
>>> spi.write([0x12, 0x34, 0xAB, 0xCD])
>>> received = spi.read(10)
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or you can refer to demo/spi_test.py, it is a example of lighting up a oled.