[Board] Adafruit Trinket

[Munsio]

Corresponding Issue for discussions: #332

[deadprogram]

At first glance, this looks great @Munsio thank you very much for the contribution.

@aykevl any comments before I merge it?

[Munsio]

If you say it looks fine i would like to test it before you merge it. (as stated in the issue i didn't try to run any code on it cause i wasn't sure that it won't brick it)

I get home at aprox. 18:00 GMT and try running the blinky example on it.

[deadprogram]

One note: I would use the same instructions to put the code on it with tinygo build as the ItsyBitsy. https://tinygo.org/microcontrollers/itsybitsy-m0/#uf2

The UF2 bootloader works quite well and quickly/safely on the various Adafruit boards that support it.

[deadprogram]

It is also useful to compare your pin mappings to something like https://github.com/adafruit/ArduinoCore-samd/blob/master/variants/trinket_m0/variant.cpp

[Munsio]

I checked it with the file you mentioned and saw that i didn't provide the DotStart and USB-Host Pins - i am not sure if they should be added? The rest seems okay, there are some placeholder pins described which i also not know if they should be included.

[deadprogram]

The dotStar requires a bitbanging-style SPI interface, so we do not have that yet.

The USB-host pins you will need, in order to use the serial over USB something like this: https://github.com/tinygo-org/tinygo/blob/master/src/machine/board_itsybitsy-m0.go#L39-L43

[aykevl]

In general this looks good but testing it on real hardware would be necessary to merge.
It's unlikely you'll really brick the device, certainly when you flash using the bootloader.

[Munsio]

Blinky is working and Serial is working - if you want you can merge it

[deadprogram]

This should be GPIO_SERCOM_ALT here, I think.

[deadprogram]

I think this PR is about ready to merge, from what I can tell.

Only thing is, it greatly complicates merging my own PR #331 in either case there will be some conflicts to resolve, but I think my changes are fewer, so would better to merge it first, then resolve this one, and merge it.

Any opinions on this?

[Munsio]

For me it is okay if you want to merge #331 first.
The other question is should we wait with this merge-request until i also implemented the I2S to the trinket or should this be a second PR just adding the sound feature.

[deadprogram]

It will probably require some additions to get it to compile with the I2S changes. Getting it to work with a separate mic is another story. As long as it compiles for now would be enough for me.

[aykevl]

Quickly reviewed it again and LGTM (assuming it has been tested). Not merging because of #333 (comment).

[deadprogram]

@Munsio the I2S PR was merged. Can you please rebase dev into this branch, and make sure that your example still builds as you expect? Thank you.

[deadprogram]

If you rebase dev into your branch, you will discover the following when trying to build your example:

$ tinygo build -size short -o test.elf -target=trinket-m0 examples/blinky1
# machine
src/machine/machine_atsamd21.go:678:16: undeclared name: I2S_SCK_PIN
src/machine/machine_atsamd21.go:679:15: undeclared name: I2S_WS_PIN
src/machine/machine_atsamd21.go:680:15: undeclared name: I2S_SD_PIN

This is what I was referring to in #333 (comment)

[deadprogram]

Thank you very much for all the great work on this @Munsio now merging. Take a victory lap!