Enable json overriding ESP8266 default baud rate

[desmond-blue]

Description

Got a question here about configuring ESP8266_DEFAULT_BAUD_RATE in mbed_app.json, I think a small modification is able to achieve that.

Pull request type

[x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

Release Notes

[0xc0170]

This should fix #11300 (same as url reported above)

[ciarmcom]

@desmond-blue, thank you for your changes.
@ARMmbed/mbed-os-ipcore @ARMmbed/mbed-os-maintainers please review.

[michalpasztamobica]

Thanks for the PR @desmond-blue !
I wonder however if it wouldn't be neater to accomplish this in a similar manner we do for other configurable items, such as pins or buffer size?
They usually get added to mbed_lib.json, which means they are available in the code as MBED_CONF_ESP8266_XXX_YYY, for example here, and can be set in mbed_app.json per target with esp8266.xxx-yyy.

@VeijoPesonen , what do you think?

[teetak01]

It would make sense to add entry to mbed_lib.json and define there the default baudrate.

[AnttiKauppila]

Please use mbed_lib.json instead

[AnttiKauppila]

Modify https://github.com/ARMmbed/mbed-os/blob/master/components/wifi/esp8266-driver/mbed_lib.json
to have one extra config like:
"baudrate": { "help": "Baudrate for ESP8266, defaults to 115200", "value": 115200 }
Then in code you can use "MBED_CONF_ESP8266_BAUDRATE" instead of defining "ESP8266_DEFAULT_BAUD_RATE"

[michalpasztamobica]

To avoid confusion perhaps this config could be called uart_baudrate or serial_baudrate, to avoid an impression that this directly influences the WiFi communication speed, which might be a primary interest of many users.
I realize that the serial baudrate in fact throttles the module's communication speed, but I think we should be specific with the naming, whenever we can afford it :).

[star297]

Could this override setting go in the same area as the ESP8266 tx and rx pin settings to keep things nice and tidy?

Perhaps an update on the ESP8266 firmware update page would be an idea, I have been using the ESP8266 at 921600 on all targets above 100Mhz for some months now, its a considerable speed improvement even without hardware control.

[desmond-blue]

Really appreciate the comments, I've modified it accordingly, would you review it again? Thanks.

[michalpasztamobica]

Thanks, @desmond-blue , that's exactly what I meant :)

[0xc0170]

CI started

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CI started

[mbed-ci]

Test run: FAILED

Summary: 3 of 11 test jobs failed
Build number : 1
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_cloud-client-test
• jenkins-ci/mbed-os-ci_greentea-test
• jenkins-ci/mbed-os-ci_dynamic-memory-usage

[0xc0170]

CI restarted

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 2
Build artifacts

[star297]

Has this fix been merged with the latest Mbed-os (online version 5.14) yet?
I have tried testing with the HTTP-example as per my comments here:
https://os.mbed.com/questions/86806/How-to-change-ESP8266-default-WiFi-baud-/
but no luck, but I'm probably doing it wrong.

[michalpasztamobica]

Hi @star297 , yes, it is available in mbed-os 5.14. Online version should be just the same.
However, in the process of code review (see above) some small modifications were made and the variable that you need to modify in your mbed_app.json file is actually called serial-baudrate and not esp8266-baudrate.

This diagnosis is just my blind guess. If I guessed wrong and you still get "no luck", please provide your mbed_app.json file and a more detailed description of the exact error you are getting (such as compilation output. I am sure we'll work it out :) .

[star297]

Hi Michal, yes, I have that set to serial-baudrate but not working, if you scroll down to the bottom of my question you will see the the mbed_app.json file in detail.

https://os.mbed.com/questions/86806/How-to-change-ESP8266-default-WiFi-baud-/

It may simply be I have that in the wrong section.

Terminal output:

Mbed OS version 5.13.4

[NWKH] Connecting to network...
[NWKH] Failed to connect to network (-3012)
Cannot connect to the network, see serial output

That Mbed OS version is a bit odd, I have updated and checked version is 5.14 in the Revision History. (Side tracking, Jimmy Brisson has an issue with his PC clock his entries are always 14 Feb 2017, I do find that a bit confusion when switching revisions.)

Compilation output:

Warning: L3912W: Option 'legacyalign' is deprecated.
Warning: 'MBED_RAM_START' macro redefined [-Wmacro-redefined] in "tmp/A4VEuA", Line: 44, Col: 9
Warning: 'MBED_RAM_SIZE' macro redefined [-Wmacro-redefined] in "tmp/A4VEuA", Line: 45, Col: 9
Success: Success!

[michalpasztamobica]

Sorry, I didn't catch where the mbed_app.json was...

To use this option you need to add it like this:

"target_overrides": {
        "*": {
            "esp8266.serial-baudrate": 921600,

This will configure the baudrate for all targets. You can put it under any of your targets instead (for example under "NUCLEO_F401RE").

[star297]

I get this compile error:

Error: Attempt to override undefined parameter 'esp8266.serial-baudrate' in 'application[*]'
Info: Unable to download. Fix the reported errors...

[michalpasztamobica]

Are you sure you are compiling for a platform that uses esp8266?
Can you please try to put it into the section of a target that surely uses esp8266? Pereferably, right after "esp8266.provide-default" : true?

I tried it on my setup and compilation for K64F + ESP8266 worked fine...

[star297]

mbed-os revision 6691 is the problem, switch to revision 6698 and it does work, I can set the baud rate.

However, unfortunately, Mbed's ESP8266 driver is not fast enough to work at 921600, it will connect but struggles handling HTTPS, but it does work fine at 460800 which is a vast improvement over 115200.

I have also tried this:
https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-wifi/
This also works and I do get the correct connected AP RSSI level.

Thank's for your time Michal :)