Feature upgrades for ABP, add errorReadout, poll after Retry Class A and more

[flhofer]

Hello! [EDITED]

I made some changes to the library for a project I worked on, so I created a pull request for the most useful ones.

Changes in general function.

• sendBytes returns now UNSUCCESSFUL_RECEIVE if the sent frame message is confirmed, but no response has been received
• poll now includes a flag modem_only to only listen to the modem's output. Useful to poll again if a confirmed message does not get through and the modem retires in the background.
• poll added a check for receive length. If length is 0, we get a UNSUCCESSFUL_RECEIVE and not SUCCESSFUL_RECEIVE.

New methods

• getters for Bandwidth, CodeRate, Frequency, DR, WDT, Power, PowerIndex, RSSI, SNR, FCU and FCD frame counters
• setters for LoRaWan power index (max TX power), data rate, FCU and FCD frame counters; Useful for ABP manual operation and when restoring from EEPROM/Flash
• getStatus to read the modem status, e.g, sending, RX1 window open, ecc.. (requires Firmware >= 1.05)
• getLastError to read and return the last error code in the receive buffer. Adds also an enumeration and text constants
• added methods setChannel, setRx2Channel, and SetChannelStatus to configure, enable and disable channels. Useful for the configuration of channels 4-8 when running ABP and recovering status from EEPROM.
• setChannelDCycle to modify a channel's duty cycle. This might be useful if you don't use all default channels of a band, thus can increase the remaining channel's DC
• setRX1Delay to modify the waiting time between TX and the first window opening. May be needed on custom Network servers when operating in ABP.

Other changes

• added a constant TTN_DEFAULT_TIMEOUT as a default timeout value
• minor additions such as init values for private variables, range and size adjustments for arrays..
• Added private methods to standardize response parsing parseBytes, and setters for modems with more parameters to reduce the number of strings, - i.e., total number of bytes needed -, for the implementation of the library

Final note

I tested the code with a TTN Uno board on a private LoRaWan server. There may be some typos as I had to manually apply some changes from my version as it holds way more features. And yes: I will push docs and examples to the branch while this request gets rolling. I know it takes some time for review, and it's better to get started soon. 😃

[CLAassistant]

All committers have signed the CLA.

[jpmeijers]

The overall quality of this PR looks very good to me. Two small issues:

• Typo in define TTN_UNSUCESSFUL_RECEIVE, but I see that was my mistake in a previous PR. Let's fix it in a different PR than this one.
• I do not like abbreviations like mdmonly. Let's rather be more descriptive like modem_only. Also with TTN_DEFAULT_TOUT=>TTN_DEFAULT_TIMEOUT, pos=>position, drmin=>dr_min, idx=>index, CMPERR_TABLE=>COMPARE_ERROR_TABLE, etc

[flhofer]

@jpmeijers Thanks for the quick reply! Didn't expect that. I have more proposals. I will apply your proposed changes and upload also some documentation soon. Some I noticed too

[flhofer]

@jpmeijers Your comment on TTN_UNSUCESSFUL_RECEIVE made me recheck the code. I actually found that too. Indeed, the submission I made yesterday was onle the changes of last year. I added thus now the rest and made a first documentation. I might still do some refactoring.. 😃

More updates soon

[flhofer]

@jpmeijers @johanstokking Refactoring done. Also fixed a duty cycle preset issue for EU868. The default 8 channels span over 2 bands, G and G1, both set to 1%. Thus each of them may use 1/3 for channel 1-3 or 1/5th for channel 4-8 of the band's duty cycle of 1%, not 1/8 of 1% as it was until now.

Explanations here

[jpmeijers]

Looking at the commands this library sends to the RN2483 when configured for EU868, I agree it does not look exactly as we want. The library uses the same configureChannels() for both OTAA and ABP. I think this needs to change. In the case of OTAA only the LoRaWAN default channels for the region should be configured, as the rest will be pushed by the network in the Join Accept. Only in the case of ABP we should manually configure all the channels and their duty cycles.

This is however a bigger change, and not a simple fix we should do in this PR.

@johanstokking let's merge this PR first, then we can work on fixing the RX2 window, and other issues with the configured channels.

[johanstokking]

@johanstokking let's merge this PR first, then we can work on fixing the RX2 window, and other issues with the configured channels.

I agree. Thanks a lot @flhofer for implementing and @jpmeijers for reviewing.