mzachmann / lightlora_micropython

Lightweight Interrupt-driven Semtech SX127x Library for MicroPython

A MicroPython Library for Controlling a Semtech SX127x LoRa Chip

This is yet another library for controlling an SX127x Semtech chip. This is entirely interrupt driven (transmit and receive) with callbacks.

For power usage, you can sleep the CPU while waiting for an interrupt during transmit and receive cycles.

There is a nearly exact copy of this library for Arduino here https://github.com/MZachmann/LightLora_Arduino

Installation

The library (LightLora) folder can just be copied and used as-is in a project.

Usage

During setup call

from LightLora import lorautil

lru = lorautil.LoraUtil()

During the loop you can

if lru.isPacketAvailable():
	pkt = lru.readPacket()
	print(pkt.msgTxt)
...
txt = "Hello World"
lru.sendPacket(0xff, 0x11, txt.encode()) # random dst, src at

The packet definition is:

class LoraPacket:
	def __init__(self):
		self.srcAddress = None
		self.dstAddress = None
		self.srcLineCount = None
		self.payLength = None
		self.msgTxt = None
		self.rssi = None
		self.snr = None

Customization

The ports for the LoRa device are set in spicontrol.py for now.

The _doTransmit and _doReceive methods in lorautil.LoraUtil are the callbacks on interrupt.

Changelog: Jul 3, 2018 -

• In lorarun.py (the example) make lr a global so comm options can be changed manually before calling doreader()
• Add a synchronous send method in lorarun.py since the sendPacket method is now asynchronous
• add reset, sleep, isPacketSent, and setFrequency methods to LoraUtil to mimic the Arduino implementation
• add power_pin option to sx127x parameter set
• use signal bandwidth as integer

lightlora_micropython's Issues

License file?

The license terms are unclear at the moment. Is this another MIT-licensed project?

AttributeError: 'module' object has no attribute 'SpiControl'

I test this code to pyboard,but some error info as follow show:

from LightLora import sx127x
from LightLora import spicontrol
from LightLora import lorautil
l = lorautil.LoraUtil()
Traceback (most recent call last):
File "", line 1, in
File "LightLora/lorautil.py", line 32, in init
AttributeError: 'module' object has no attribute 'SpiControl'

How to solve this issue.Thanks!

Doesn't work with Loboris MicroPython

Thanks for the great library. There doesn't appear to be any other easy to use Lora library that works with MicroPython with a liberal license, so happy to find yours.

It doesn't work with the Loboris version of MicroPython though and that seems by far the best version for ESP32's - https://github.com/loboris/MicroPython_ESP32_psRAM_LoBo

The only change needed is in sx127x _prepIrqHandler. Would you accept a pull request for this?

_thread library needs updating

I'm not good with this pull request technology. I got it working (I think) with, in sx127x.py:

	self._lock = _thread.allocate_lock()

and then:

def acquire_lock(self, lock=False):
	if self._lock:
		if lock:
			self._lock.acquire()
		else:
			self._lock.release()

Also, I think it would be easier for folks if it indented with spaces instead of tabs

setFrequency should work on all frequencies

In file sx127x.py you have a look up table instead of running the following calculation:

	def setFrequency(self, frequency):
		self._frequency = frequency
		k = ((frequency<<19)//32000000)
		self.writeRegister(REG_FRF_MSB, (k>>16)&0xff)
		self.writeRegister(REG_FRF_MID, (k>>8)&0xff)
		self.writeRegister(REG_FRF_LSB, k&0xff)

lifted from:
https://github.com/kersing/ESP-1ch-Gateway-v5.0/blob/master/ESP-sc-gway/_loraModem.ino#L314

Also support a raw bytes message as well as the packet with src/dst headers

The Lora devices I communicate with don't use the packet structure that this has https://github.com/MZachmann/LightLora_MicroPython/blob/master/LightLora/lorautil.py#L6

So I'd like a way to also support this 'raw' message as well as the packet format. Would that be ok?