dac8532 Namespace Reference

Functions
	output_json ()
	parse_args (raw_args)
	write ()

Variables
int	cs = 23
	register_data = dict([('control', 0x00), ('data_h', 0x00), ('data_l', 0x00)])

Function Documentation

output_json()

dac8532.output_json

(

)

Prints a JSON of the register_data for development and testing.

Definition at line 123 of file dac8532.py.

def output_json():
    """Prints a JSON of the register_data for development and testing."""
    print(json.dumps(register_data, sort_keys=True, indent=4))
 
 

parse_args()

dac8532.parse_args

(

raw_args

)

Parses the args into ready to write register_data.

Definition at line 128 of file dac8532.py.

def parse_args(raw_args):
    """Parses the args into ready to write register_data."""
    # First parse the CLI.
    parser = argparse.ArgumentParser()
    parser.add_argument("--port", type=str, default="A",
                        help="Output Port: A, B default A")
    parser.add_argument("--output", type=str, default="32767",
                        help="Output Voltage: 0 to 65535 default 32767")
    parser.add_argument("-t", "--test", action="store_true",
                        help="Print JSON of register_data")
    args = parser.parse_args(raw_args)
 
    # Process the control register
    register_data['control'] = 0x30
    if (args.port == "A"):
        register_data['control'] = 0x30
    if (args.port == "B"):
        register_data['control'] = 0x34
 
    # Process the data registers
    register_data['data_h'] = 0x00
    register_data['data_l'] = 0x00
    raw_output = int(args.output)
    if (raw_output < 0):
        raw_output = 0
    if (raw_output > 65535):
        raw_output = 65535
    register_data['data_h'] = raw_output >> 8
    register_data['data_l'] = raw_output & 0xFF
 
    # Optionally output register state for development purposes
    if args.test:
        output_json()
        exit()
 
 
# Functions that read or write device registers
 
 

write()

dac8532.write

(

)

Writes to the DAC using SPI

Definition at line 167 of file dac8532.py.

def write():
    """Writes to the DAC using SPI"""
 
    GPIO.setmode(GPIO.BCM)
    GPIO.setwarnings(False)
    GPIO.setup(cs, GPIO.OUT)
    GPIO.output(cs, 1)
 
    spi = spidev.SpiDev()
    spi.open(0, 0)
    spi.max_speed_hz = 20000
    spi.mode = 0b01
 
    GPIO.output(cs, 0)
    spi.writebytes([register_data['control'], register_data['data_h'], register_data['data_l']])
    GPIO.output(cs, 1)
 
 
# Convert CLI options to register_data

Variable Documentation

cs

int dac8532.cs = 23

Definition at line 115 of file dac8532.py.

register_data

dac8532.register_data = dict([('control', 0x00), ('data_h', 0x00), ('data_l', 0x00)])

Definition at line 117 of file dac8532.py.