ports/esp8266: Software Serial (SoftUART) support. #7784

MrJake222 · 2021-09-13T22:42:28Z

Software serial communication for ESP-8266

class SoftUART - half-duplex serial communication

SoftUART implements the standard UART/USART half-duplex serial communications protocol.
Supported communication parameters are:

8 data bits,
1 stop bit,
No parity,
1M-baud tested with nothing running in the background.

Initialization

from machine import SoftUART, Pin

uart = SoftUART(tx=Pin(2), rx=Pin(4))
uart.init(baudrate=9600, timeout=0)

Constructors

class machine.SoftUART(tx=Pin(Tx), rx=Pin(Rx))
- Tx - pin used for data transmission
- Rx - pin used for data reception

Methods

SoftUART.init(tx=Pin(Tx), rx=Pin(Rx), baudrate=9600, bits=8, parity=None, stop=1)
Basically constructor without additional memory allocation.
- Tx - pin used for data transmission
- Rx - pin used for data reception
- baudrate - data rate
- bits - data bits (only 8 supported)
- parity - data parity bit (only None supported)
- stop - stop bits (only 1 supported)
SoftUART.deinit()
Frees memory.
SoftUART.read(n)
SoftUART.readline()
Unreliable.
SoftUART.readinto()
Not tested.
SoftUART.write(buf)

Stream API

SoftUART supports stream API (select.select, select.poll, etc.)

Work done

Based on work of:

I did a clean-up, fixed code formatting, tried to stay as close as possible to machine.UART implementation. Examples.

Code copied from https://github.com/p-v-o-s/micropython.

Link: https://github.com/plieningerweb/esp8266-software-uart.

Link: https://github.com/juancgalvez/Arduino-esp8266-Software-UART.

select.select now works.

Ensuring that timing is correct (to allow for 115200 baud).

Allows to work with 1200 baud or lower.

Used provided tools/codeformat.py.

Merge branch 'master' into esp8266-softuart

Now multiple instances of SoftUART possible. softuart.c: Removed os_printf calls (they reset my ESP). softuart.c: Moved validation to machine_softuart.c (as in regular UART). machine_softuart.c: Tx/Rx can now only be defined via constructor (as uart_id regular UART). machine_softuart.c: Unsupported parameters now raise ValueErrors.

esp8266/examples: Added 2 examples for SoftUART (read, write).

peterhinch · 2021-09-14T04:55:28Z

This sounds very useful. Has it been tested with uasyncio StreamReader and StreamWriter?

MrJake222 · 2021-09-14T07:04:21Z

No.

EDIT
I'm not sure if merging it right now is a good idea. The performance of the library itself is, well, undefined. Write blocks for entire byte (~1 ms). Read blocks in interrupt also for a whole byte.

Unfortunately I can't find any reference for how to use timers (God I wish It'd be as simple as avr). Anyone can help with some documentation about timers? This claims to use best practices but writing still blocks.

EDIT 2
But I see implementations of SoftSPI and SoftI2C are doing exactly the same.

mmmdwyer · 2021-09-19T18:51:33Z

For what it is worth, I tested it out in a rather non-strenuous task: Decoding packets from IKEA's Vindriktning air quality sensor. It's a burst of about 120 bytes every 30s or so at 9600bps. It's been working great! My full project requires SoftI2C and MQTT running at the same time, but @MrJake222 's binary release doesn't include SoftI2C and it'll take a bit longer before I'm up to building my own. But I look forward to seeing if it still works when multiple timing-sensitive stacks are running.

jimmo · 2021-09-20T02:36:57Z

Thanks @MrJake222 ! This is definitely something we see a few requests for, and glad to hear from @mmmdwyer that it's working well.

We probably need to clarify the license situation for the softuart code and ensure that we're compliant. My understanding is that it's almost exactly based on https://github.com/plieningerweb/esp8266-software-uart which is MIT, so at the very least we need to include attribution and copyright headers. It might also be possible to use it as a submodule instead?

MrJake222 · 2021-09-21T08:16:11Z

It might also be possible to use it as a submodule instead?

What do you mean? Like, making it separate from machine module?

jimmo · 2021-09-21T09:29:28Z

It might also be possible to use it as a submodule instead?

What do you mean? Like, making it separate from machine module?

A git submodule. Like the other libraries in the lib directory.

MrJake222 · 2021-09-21T09:55:50Z

Ahh like that... But which repository should it be linked to? plieningerweb one? Or mine for example?

jimmo · 2021-09-21T14:23:52Z

Ahh like that... But which repository should it be linked to? plieningerweb one? Or mine for example?

In general, if this were a third-party library, then it should point to the upstream repo of that library. I think that's what plieningerweb is (unless you've made modifications?).

That's why I was asking where the code comes from. I think in this case it's a small enough that the submodule is unnecessary, but we need to sort out exactly where this code comes from and what the license is.

MrJake222 · 2021-09-21T14:29:09Z

I've linked the forum link. There you can see that at least 3 people have attempted to port this. I've only adapted dmascord version (which I think based on p-v-o-s one, which is based on the original one). I'll ask him to clarify this.

EDIT
As far as I can see the code across the repos linked is almost identical to upstream repository (so the license is MIT) and I can't tell you about modifications made because I've only really touched the API part.

dmascord · 2021-09-21T22:25:15Z

Hi guys,

The code licensed is as per original MIT. It has been adapted from the code bases mentioned above, hardly any of the work is actually my own code, all I did was just making it work as a micropython module with a recent micropython build.

I find the implementation quite stable at a variety of baud rates. I found some ports worked fine at 9600 and others at 115200, so combining what I could had it working at most baud rates, even higher than 115200.

Cheers,

Damien

MrJake222 · 2021-09-21T22:27:48Z

Same here, I've edited API a little bit, changed code style and commit message style to be compatible with this repo and that's about it.

beyonlo · 2021-10-17T02:42:08Z

Hello. Great works!

This PR will works with ESP32 too?

Of course that I see the PR name as target ESP8266 ("ports/esp8266:"), but as ESP32 is from Espressif as well and a bit similar, I would like if will works.

Thank you.

dmascord · 2021-10-17T05:37:37Z

I tested an old version of the code, and it worked fine on ESP32, so it should be fine, but can't guarantee.

MrJake222 · 2021-10-17T09:12:45Z

I've removed ESP32 code as I was unable to test it.

michelhe · 2021-11-29T01:01:20Z

Hey @MrJake222 @jimmo , what needs to be done next in order to get this into upstream? :)

Can confirm that its working great for me with 9600 baud on this little project:
https://github.com/michelhe/pimp-my-marax/

AlanBell · 2022-02-23T23:24:56Z

This doesn't appear to implement the UART.any() method which should return the number of characters that can be read without blocking (the size of what is in the buffer) or simply 1 or 0 depending on whether there is anything to read.

tomklapka · 2022-04-26T11:22:30Z

Is there any idea when this could be merged ? It's very demanded especially on 8266 devices.

ywz978020607 · 2022-06-28T00:51:53Z

Hello. Great works!

This PR will works with ESP32 too?

Of course that I see the PR name as target ESP8266 ("ports/esp8266:"), but as ESP32 is from Espressif as well and a bit similar, I would like if will works.

Thank you.

esp32software serial mr has been submitted, i have used for a long time, but till now to submit, you can refer this. #8829

ThinkTransit · 2022-07-30T11:21:14Z

I've removed ESP32 code as I was unable to test it.

Great work.

Do you still have a copy of the esp32 code, I would be more than happy to test it out as I really need this feature!

MrJake222 · 2022-07-30T11:24:27Z

See original post for the links. See other repos. There should be some esp32 code.

ThinkTransit · 2022-07-30T15:12:47Z

See original post for the links. See other repos. There should be some esp32 code.

Thanks for the pointer, unfortunately I have struggled to integrate any of the linked code. I'm using an ESP32-S3 which requires idf V4.4 and I think this might be causing the problem. I'm getting a cryptic error I haven't come across before:

Bootloader binary size 0x4910 bytes. 0x36f0 bytes (43%) free. [5/249] Generating ../../genhdr/qstr.i.last FAILED: genhdr/qstr.i.last /home/patrick/esp/micropython/ports/esp32/build/genhdr/qstr.i.last

garudaonekh · 2022-08-25T09:41:43Z

@MrJake222 I tested your repos and it seems to work well so far to communicate with SIM800L.

But I have an issue with RXBufffer. when I read all SMS from SIM, some data is missed so I think it's related with rxbuffer. But there's no option to set RXBuffer in your SoftUART.

MrJake222 · 2022-08-31T12:08:47Z

But there's no option to set RXBuffer in your SoftUART.

You mean it's size?

robtinkers · 2023-02-16T00:12:32Z

I documented the process of building my own firmware with SoftUART and micropython-lib here:

https://gist.github.com/robtinkers/b653b045e3425903eff681d278e3823c

I hope this helps someone out!

…n-main Translations update from Hosted Weblate

projectgus · 2024-03-07T23:52:35Z

This is an automated heads-up that we've just merged a Pull Request
that removes the STATIC macro from MicroPython's C API.

See #13763

A search suggests this PR might apply the STATIC macro to some C code. If it
does, then next time you rebase the PR (or merge from master) then you should
please replace all the STATIC keywords with static.

Although this is an automated message, feel free to @-reply to me directly if
you have any questions about this.

dmascord and others added 14 commits September 13, 2021 16:13

ports/esp8266: Added SoftUART support.

dbf643f

Code copied from https://github.com/p-v-o-s/micropython.

esp8266/softuart.c: Integrated the latest code from plieningerweb.

d90a497

Link: https://github.com/plieningerweb/esp8266-software-uart.

esp8266/softuart.c: Adapted performance improvements from juancgalvez.

2fdf6d9

Link: https://github.com/juancgalvez/Arduino-esp8266-Software-UART.

ports/esp8266: Added implementation for ioctl.

98eb666

select.select now works.

ports/esp8266: Added MP_FASTCODE macro.

6961d22

Ensuring that timing is correct (to allow for 115200 baud).

esp8266/softuart.h: Changed bit rate to be a 32bit number.

4be45ad

Allows to work with 1200 baud or lower.

ports/esp8266: Fixed code formatting.

924c60d

Used provided tools/codeformat.py.

lib/lwip: Updated to match upstream.

66cf0b0

ports/esp8266: Deleted espmissingincludes.h.

67c2dc4

ports/esp8266: Added software UART module.

bada178

Merge branch 'master' into esp8266-softuart

ports/esp8266: Softuart code cleanup.

fc60f49

esp8266/machine_softuart.c: Fixed wrong pointer.

8f8abcc

esp8266/examples: Added 2 examples for SoftUART (read, write).

esp8266/examples: Fixed code formatting.

b883820

esp8266/machine_softuart.c: More verbose API, moved tx/rx to kwargs.

e536ad3

dpgeorge added the port-esp8266 label Sep 21, 2021

tannewt pushed a commit to tannewt/circuitpython that referenced this pull request Mar 24, 2023

Merge pull request micropython#7784 from weblate/weblate-circuitpytho…

5ae3be1

…n-main Translations update from Hosted Weblate

This was referenced Feb 29, 2024

global: Remove the STATIC macro. #13763

Merged

global: Prune trailing whitespace. #13777

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ports/esp8266: Software Serial (SoftUART) support. #7784

ports/esp8266: Software Serial (SoftUART) support. #7784

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ports/esp8266: Software Serial (SoftUART) support. #7784

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ports/esp8266: Software Serial (SoftUART) support. #7784

Conversation

MrJake222 commented Sep 13, 2021 • edited Loading

Software serial communication for ESP-8266

class SoftUART - half-duplex serial communication

Initialization

Constructors

Methods

Stream API

Work done

Based on work of:

peterhinch commented Sep 14, 2021

MrJake222 commented Sep 14, 2021 • edited Loading

mmmdwyer commented Sep 19, 2021

jimmo commented Sep 20, 2021

MrJake222 commented Sep 21, 2021

jimmo commented Sep 21, 2021

MrJake222 commented Sep 21, 2021

jimmo commented Sep 21, 2021

MrJake222 commented Sep 21, 2021 • edited Loading

dmascord commented Sep 21, 2021

MrJake222 commented Sep 21, 2021

beyonlo commented Oct 17, 2021 • edited Loading

dmascord commented Oct 17, 2021

MrJake222 commented Oct 17, 2021

michelhe commented Nov 29, 2021 • edited Loading

AlanBell commented Feb 23, 2022

tomklapka commented Apr 26, 2022

ywz978020607 commented Jun 28, 2022 • edited Loading

ThinkTransit commented Jul 30, 2022

MrJake222 commented Jul 30, 2022

ThinkTransit commented Jul 30, 2022

garudaonekh commented Aug 25, 2022

MrJake222 commented Aug 31, 2022

robtinkers commented Feb 16, 2023

projectgus commented Mar 7, 2024

MrJake222 commented Sep 13, 2021 •

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MrJake222 commented Sep 14, 2021 •

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MrJake222 commented Sep 21, 2021 •

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beyonlo commented Oct 17, 2021 •

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