testing: irtest usage to test Espressif's RMT peripheral.

[tmedicci]

Summary

• system/irtest: Set irtest command line size to CONFIG_LINE_MAX

  • Let irtest command line size be equal to CONFIG_LINE_MAX so that bigger (or smaller) commands can be set.

• system/irtest: Avoids silently truncating long write_data commands

  • Long write_data commands can be truncated without any check due to the maximum size of CONFIG_SYSTEM_IRTEST_MAX_SIRDATA. This PR adds a check to avoid a silent fail.

• system/irtest: Fix issues regarding portability and buffer size

  • This PR fixes issues regarding portability by using variables with fixed width (and their format macro constants).

• examples: Remove deprecated rmtchar example application

  • The upper-half RMT driver is no longer available on NuttX. Instead, Espressif's RMT peripheral was bound directly to the lirc driver. For testing purposes, use the irtest application. NuttX OS PR espressif/rmt: replace rmtchar with arch-specific lirc adapter nuttx#18654 removed the upper-half driver interface used by this application, so removing it does not break any existing feature on NuttX.

Impact

Impact on user: Yes. Improve user's experience when trying irqtest testing application.

Impact on build: No.

Impact on hardware: No.

Impact on documentation: No.

Impact on security: No.

Impact on compatibility: No.

Testing

Build the rmt defconfig of any Espressif SoC, interconnect output and input pins externally and run irqtest. For ESP32-C6-DevKitC-1 V1.2, for instance:

Building

make -j distclean
./tools/configure.sh -S esp32c6-devkitc:rmt
kconfig-tweak -e SYSTEM_IRTEST
make olddefconfig
make flash ESPTOOL_PORT=/dev/ttyUSB0
picocom -b 115200 /dev/ttyUSB0

Running

Connect GPIO 8 (RMT output pin) to GPIO 2 (RMT input pin) externally and run irqtest:

nsh> irtest
$open_device(/dev/lirc0)
$open_device(/dev/lirc1)
$write_data(1) 16777229 16 16777235 23
$read_data(0,4)
16777229, 16, 16777235, 23

Results

Read data equals written data. Loopback test succeeded!

[cederom]

Thank you @tmedicci :-)

Would it be possible to mark this change as breaking with a short note that rmtchar is removed and replaced by irtest?

We also need documentation update there are references to rmtchar see https://nuttx.apache.org/docs/latest/search.html?q=rmtchar&check_keywords=yes&area=default :-)

[tmedicci]

Hi @cederom !

Would it be possible to mark this change as breaking with a short note that rmtchar is removed and replaced by irtest?

I updated PR's description (and the respective commit) with the following message:

The upper-half RMT driver is no longer available on NuttX. Instead, Espressif's RMT peripheral was bound directly to the lirc driver. For testing purposes, use the irtest application.

I also added the breaking change tag, but it isn't really a breaking change because it just removed a deprecated application. The "breaking change" was introduced by apache/nuttx#18654

NuttX OS PR https://github.com/apache/nuttx/pull/18654 removed the upper-half driver interface used by this application, so removing it does not break any existing feature on NuttX.

We also need documentation update there are references to rmtchar see https://nuttx.apache.org/docs/latest/search.html?q=rmtchar&check_keywords=yes&area=default :-)

I'll prepare a PR for updating on NuttX OS repo, thanks!

[acassis]

@xiaoxiang781216 this irtest in C++ will require more memory (normally just enabling libcxx will consume more 100KB even with almost all features disabled: exceptions, RTTI, etc). So it will a show stopper for many small MCUs.

Is it possible to convert it from C++ to C? I noticed the code is mostly simple C, except for some templates usage.

[tmedicci]

Updated documentation PR at apache/nuttx#18788.

[cederom]

@xiaoxiang781216 this irtest in C++ will require more memory (normally just enabling libcxx will consume more 100KB even with almost all features disabled: exceptions, RTTI, etc). So it will a show stopper for many small MCUs.

Is it possible to convert it from C++ to C? I noticed the code is mostly simple C, except for some templates usage.

+1 :-) This looks C :D

[cederom]

Looks okay thank you @tmedicci :-) We can update C++ -> C in a free moment but we have working solution right now :-)