add support for Pi Pico + sx1262 module to LoRaWAN examples

[K4KDR]

Hello! After finding success w/ the LoRaWAN examples using my Arduino UNO + sx1278 hardware, I wanted to be able to utilize the excellent Waveshare SX1262 LoRa Node Module for Raspberry Pi Pico (https://www.waveshare.com/pico-lora-sx1262-868m.htm) that is a direct header plug-in to the Pi Pico microcontroller.

A previous issue (#729) identified the syntax required to use the sx1262 module.

After modifying my local code to successfully uplink a LoRaWAN payload using the Pi Pico / sx1262 combination, I wanted to share the code if by chance you would like to integrate this hardware option into the list of choices in the LoRaWAN examples.

Thanks!

-Scott, K4KDR

[HeadBoffin]

I've not put comments on the other files, but they translate over.

[HeadBoffin]

Sorry, rude of me not to say, thanks for this, very useful consolidation of the prior issues.

[jgromes]

Thank you for the contribution Scott! However, I'm asking myself whether we need to be adding more example LoRa boards to the LoRaWAN examples ... surely there are still many more we are missing and new ones will be released in the future. By including these, we are basically building a database of pin maps. Fair enough, but why should that be in the RadioLib examples - and copied three times over?

My point is, this seems very similar to what @Velocet proposed in #1065. So maybe instead of kicking the can down the road we should move these pin maps somewhere else (e.g. a new repository in https://github.com/radiolib-org)?

[jgromes]

I am not sure about this - so far, these examples worked by automatically detecting the type of board. This changes that behavior. Is there any macro that is defined for that board that we could use?

[jgromes]

I don't think it can be called a "fix" when you are using the library as intended - what exactly is being fixed here?

Having to specify which SPI bus is used to connect to the module is a very basic information that even has its own section on the Wiki and in the troubleshooting guide. It's not something I want to hide from the user, if they leave everything at the default value and then insert surprised Pikachu face when it doesn't work then that suggests they know very little about the hardware they are using.

[K4KDR]

Great points - I learn so much every time you answer a question or add code to a project... THANK YOU!

One example is that I had no idea that these examples were doing any kind of hardware auto-detect! When I saw all the #if defined statements, I just assumed that the code was expecting the user to "just know" that the correct way to utilize that was to add the appropriate #define statement for their hardware. There is line just before that section that mentions Auto select MCU <-> radio connections , but that meant nothing to me since I had never heard of any such thing.

Once I found the correct syntax to use the Pi Pico + sx1262 combination, I just wanted to share that for your review. But it makes complete sense to leave references to work-arounds for specific hardware to Issues or Discussions in the repository where they can easily be found by keyword searches.

Thanks for taking the time to look at what I am doing and providing YET MORE learnings. Much appreciated!

[HeadBoffin]

Once I found the correct syntax to use the Pi Pico + sx1262 combination, I just wanted to share that for your review. But it makes complete sense to leave references to work-arounds for specific hardware to Issues or Discussions in the repository where they can easily be found by keyword searches.

There will be a Pico worked example, it's just that someone else also submitted one at the same time and we need to get the auto-pinmap thing figured. So you work will emerge as a full example, just not today!

[StevenCellist]

@K4KDR while this PR is pending a pin-table or other way to get the pinmaps in a better state than keeping multiple config.h files synchronized, I already want to thank you for your code here to get the Pico + SX1262 hat going for radiolib-org/radiolib-persistence#4. Thanks! :)

[jgromes]

@K4KDR sorry for keeping you waiting on this one - it's because I'm not entirely sure we want to keep the pin maps in the LoRaWAN examples, or rather move them to some other place. There's a discussion dedicated to this topic in #1106.

[jgromes]

Closing as radiolib-org/RadioBoards#2 was merged.