# Python LT8900 via SPI
This Python module enables a Python to talk to an LT8900 radio attached to an serial peripheral interface (SPI).
## API
### Synopsis
lt8900_spi.radio(spi_bus, spi_dev, config = None) -> instance
lt8900_spi.radio.put_register(reg, value) -> value
lt8900_spi.radio.put_register_bits(reg, bits_dict) -> value
lt8900_spi.radio.get_register(reg) -> value
lt8900_spi.radio.get_register_bits(reg, value = None) -> dictionary
lt8900_spi.radio.configure(config) -> None
lt8900_spi.radio.initialize() -> boolean
lt8900_spi.radio.set_channel(channel) -> dictionary
lt8900_spi.radio.set_syncword(syncword) -> None
lt8900_spi.radio.fill_fifo(message, include_length = True) -> list
lt8900_spi.radio.transmit(message, channel = None) -> boolean
lt8900_spi.radio.multi_transmit(message, channels, retries = 3, delay = 0.1) -> boolean
lt8900_spi.radio.start_listening(channel) -> boolean
lt8900_spi.radio.stop_listening() -> boolean
lt8900_spi.radio.receive(channel = None, wait = False, length = None, wait_time = 0.1) -> list
### instance.get\_register\_bits
Low-level primitive to get a named register with bitfields expanded to names.
### instance.put\_register\_bits
Low-level primitive to set a named register by bitfield value.
### instance.set\_syncword
High-level interface to syncword mechanism. The syncword can be 1, 2, 3, or 4 16-bit words long and should be provided as an array.
Example:
instance.set_syncword([1, 2, 3, 4])
### instance.transmit
Transmit a message. If a channel is specified transmit on that channel -- otherwise the current channel is queried and then used.
### instance.multi\_transmit
Transmit a message across multiple channels multiple times. This is a common pattern so this function is provided for convience.
## Example
#! /usr/bin/env python3
import time
import gpiozero
import lt8900_spi
# Need to keep this attached to drive the line high -- if the object disappears then
# the GPIO port gets reconfigured as an input port
# Note broadcom pin numbers are used
reset_gpio = gpiozero.LED(24)
reset_gpio.on()
def reset_module_via_gpio():
reset_gpio.off()
time.sleep(0.1)
reset_gpio.on()
time.sleep(0.1)
radio = lt8900_spi.radio(0, 0, {
'reset_command': reset_module_via_gpio
})
if not radio.initialize():
raise ValueError('Initialize failed')
radio.set_syncword([0x258B, 0x147A])
radio.multi_transmit([0xB0, 0x51, 0xF0, 0x00, 0x00, 0x01, 212], [9, 40, 71], delay = 0.5)