RMT - added the ability to use extended RMT memory for a channel

[enelson1001]

Motivations

I would like to use all the RMT memory available for one channel.

Solution

See page 414 of the Technical Reference Manual

Alternatives

None

Additional context

[Dominaezzz]

See page 414 of the Technical Reference Manual

For which chip?

[enelson1001]

The technical manual referenced was for ESP32 but all devices support this option.
The option is located under the RMT_CHnCONF0 register and bit name is RMT_MEM_SIZE_CHn

Here is a summary

ESP32

• Block Size = 64x32
• RAM size = 512x32
• Channels = 8; can be either TX or RX

ESP32-S2

• Block size = 64x32
• RAM size = 256x32
• Channels = 4; can be either TX or RX

ESP32-S3

• Block size = 48x32
• RAM size = 384x32
• Channels = 8; 4TX and 4RX

ESP32-C2, ESP32-C3, ESP32-C6, ESP32-H2 (not 100% sure on C2)

• Block size = 48x32
• RAM size = 192x32
• Channels = 4; 2TX, 2RX

[enelson1001]

@Dominaezzz Are you looking at implementing this feature?

[Dominaezzz]

Nope!

[enelson1001]

OK I think I will try to implement.

[enelson1001]

I am getting close to submitting a PR.

But I have a git question that I hope someone will answer.

1. I forked esp-hal
2. Cloned the forked repository to my local pc.
3. Checked out a new branch rmt-flt-thrs-fix
4. Made changes to rmt.rs
5. Push changes to my forked copy of esp-hal
6. Created a Pull Request from the Github web site of the forked esp-hal
7. Checked out a new branch rmt-add-memsize-to-configure (but now this branch has changes I made to rmt.rs for the filter threshold fix).
8. Make changes to rmt.rs to add memsize to configure
9. If I push changes to my forked copy of esp-hal can I submit a PR that includes the changes from the previous PR (rmt-flt-thrs-fix)?

[Dominaezzz]

You can (Git/GitHub will allow you) but imo you shouldn't, makes it harder to review.
If you start your work on a fresh branch, it can be easily reviewed before the existing PR lands (I'm a little surprised it hasn't landed yet).

[enelson1001]

OK, I think I will wait a couple of days in hopes the RMT filter threshold fix PR will get pulled in.
Thank you for your response.