Implement "reliable datagram" mode

Implemented compatibility with the RadioHead library "Reliable DataGram" mode.
Received packets are "ACKed" and Transmitted packets wait for ACK response.

BREAKING CHANGES

There are "breaking changes" for anyone that had been setting the RadioHead headers directly.
There are now attributes for setting the header parameters and the rx_filter parameter for the receive function has been removed.

for send() the kwarg tx_header has been replaced by 4 individual kwargs: destination, node, identifier, flags

It is not normally necessary use the destination, node, identifier or flags awards when calling send()
They should be set during initialization using the attributes node and destination as in the examples.
The identifier and flags attributes are set automatically when using send_with_ack()
For a non-acked send() they may be set manually either via the attributes or kwargs

send() now returns a boolean status - if True, the send was completed, if False, the send timed out. Perviously a Runtime error was thrown on the time out.

Notes

It has been difficult to make this work reliably. Packets will still be missed occasionally but now they will be reported. There are attributes taht can be "tweaked" to help

rfm69.ack_delay -- set a delay before the ACK packet is sent - this is necessary when the receive unit an MCU communication to a Raspberry Pi . The MCU can send it's ACK packet before the Raspberry Pi has resumed "listening". The default setting is "None" but setting it to .1 seconds may be necessary. The Arduino RadioHead library does not allow for this "ack_delay" and it it may be difficult to get this to work, especially with a Raspberry Pi.

rfm69.retries -- set the number of ack retries

All of the existing examples will still execute without change.

There are examples for using this mode in rfm69_node1_ack.py and rfm69_node2_ack.py

other new examples
rfm69_header.py -- receive packets and display the header and packet contents
rfm69_node1.py -- uses adresses without ACK
rfm69_node2.py -- companion to rfm69_node1.py
rfm68_rpi_simpletest.py - no LED and set pins for RaspBerry Pi
rfm69_node1_bonnet.py -- similar to rfm69_node1.py but for use with RPi and bonnet -- uses buttons to sent packets

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip3 install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

1.5.1 - Added Black check, reran Black with Python 3 target.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip3 install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

1.5.0 - Upgrade to latest Pylint, implement Black formatting

We have upgraded Pylint checks to use the latest version of Pylint and implemented usage of Black Python formatting. This does not change the functionality of the code - it is designed to bring it up to current standards and make it more readable.

• Remove pinned Pylint version number from build.yml file
• Synced .pylintrc file to match Adafruit standard
• Ran upgraded Pylint and applied any changes or new disables necessary
• Ran Black formatter and allowed application of changes across entire repo

For more information on using Pylint and Black on your code, check out this guide on working with Pylint and Black

• Additionally, a packet send timeout no longer raises an error - thanks @geekguy-wy

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip3 install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

Add last_rssi attribute

This release includes:

• #23 Adds last_rssi attribute. Thanks @jerryneedell!

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip3 install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

1.3.1 - Changed CI from Travis to GitHub Actions

This release includes:

• Migrating this repository from Travis to GitHub Actions. This has no effect on the behavior of the code itself.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip3 install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

Enable interrupts for received packets

• #19 send and receive methods modified to allow interrupts from user-code.

  • Example of usage with Raspberry Pi

• #19 send can now listen after a packet is sent using new kwarg keep_listening

  • Example of usage on Microcontrollers.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

Update Simpletest

Updated simpletest to blink on-board LED when packets are received.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

minor bug fixes for empty packet handling

Fix a few bugs related to empty packet handling.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

Allow access to RadioHead packet Headers

Updated adafruit_rfm69.py to allow optional access to the RadioHead Packet Headers.

The user may optionally set and receive the 4 byte RadioHead packet header.
The default is to ignore the header as in the past.

On transmit, the user may provide a keyword argument: tx_header with a 4-tuple of bytes.
tx_header = (To,From,ID,Flags)
to set the outgoing header.

On receive, the user can request that the packet header be included at the beginning of the packet via a keyword argument: with_header.
If set to True, the header will be included as the first 4 bytes of the packet and the data payload begins at byte 4.
Also, the user may specify a keyword argument: rx_filter to reject any "non-broadcast" packets not addressed as specified. A "broadcast" message contains 0xff as the To address. Broadcast messages are always received.
If rx_filter is set to a value other than 0xff, then incoming packets with the To field not matching the rx_filter will be ignored unless the To field contains 0xff.
If rx_filter is set to 0xff then all packets are accepted.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.

update example code for Raspberry Pi compatibility

Updated rfm69_simpletest.py for compatibility with Raspberry Pi.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

To use in CPython, pip install adafruit-circuitpython-rfm69.

Read the docs for info on how to use it.