Add esp32-c5 support by Samt43 · Pull Request #202 · NorthernMan54/rtl_433_ESP

Samt43 · 2026-02-19T13:25:16Z

No description provided.

Samt43 · 2026-02-19T13:31:12Z

I could test this with an ESP32-C5, everyhting is working as expected

- Modified signalDecoder.cpp to check CONFIG_FREERTOS_UNICORE - Single-core ESP32 variants (ESP32-C3, ESP32-S2) run decoder on core 0 with priority 3 - Multi-core ESP32 variants run decoder on core 1 with priority 2 - Added documentation in README.md explaining the automatic detection Co-authored-by: NorthernMan54 <19808920+NorthernMan54@users.noreply.github.com>

Copilot

Pull request overview

This pull request adds support for the ESP32-C5 microcontroller variant to the rtl_433_ESP library. The changes configure the library to work with single-core ESP32 variants (including C5) by adjusting FreeRTOS task pinning and SPI peripheral selection.

Changes:

Modified FreeRTOS task configuration to support single-core ESP32 variants by detecting CONFIG_FREERTOS_UNICORE flag
Added ESP32-C5 to the SPI peripheral selection logic (FSPI vs VSPI)
Added new ESP32-C5 build environment with required compiler flag suppressions
Documented single-core ESP32 variant support in README
Deleted decoder_util.c file (appears problematic)

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
src/signalDecoder.cpp	Adds conditional FreeRTOS core/priority configuration based on CONFIG_FREERTOS_UNICORE flag for single-core support
src/rtl_433_ESP.cpp	Adds ESP32-C5 to the FSPI SPI peripheral selection list
src/rtl_433/decoder_util.c	Complete file deletion (278 lines) - may cause build failures
example/OOK_Receiver/update_link_flags.py	New Python script to suppress implicit function declaration warnings globally
example/OOK_Receiver/platformio.ini	Adds esp32c5_cc1101 build environment and global extra_scripts directive
README.md	Adds documentation for single-core ESP32 variant support (C3, C5, S2)

Copilot · 2026-02-20T02:29:05Z

+### Single-Core ESP32 Variants (ESP32-C3, ESP32-C5, ESP32-S2)
+
+The library automatically detects and supports single-core ESP32 variants such as the ESP32-C3/5 and ESP32-S2. The decoder task's CPU core assignment and priority are automatically adjusted based on the `CONFIG_FREERTOS_UNICORE` configuration:
+
+* **Single-core processors** (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3
+* **Multi-core processors** (ESP32, ESP32-S3): Decoder task runs on core 1 with priority 2
+
+This configuration ensures compatibility with single-core ESP32 variants that only have core 0 available, preventing boot crashes that would occur if the task were pinned to the non-existent core 1.


The documentation states that ESP32-C5 is included in the single-core list, but ESP32-C5 is actually a dual-core processor according to Espressif's documentation. Only ESP32-C3 and ESP32-S2 are single-core. This could lead to incorrect configuration or confusion. Please verify the ESP32-C5 specifications and update the documentation accordingly.

Suggested change

### Single-Core ESP32 Variants (ESP32-C3, ESP32-C5, ESP32-S2)

The library automatically detects and supports single-core ESP32 variants such as the ESP32-C3/5 and ESP32-S2. The decoder task's CPU core assignment and priority are automatically adjusted based on the `CONFIG_FREERTOS_UNICORE` configuration:

* **Single-core processors** (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3

* **Multi-core processors** (ESP32, ESP32-S3): Decoder task runs on core 1 with priority 2

This configuration ensures compatibility with single-core ESP32 variants that only have core 0 available, preventing boot crashes that would occur if the task were pinned to the non-existent core 1.

### Single-Core ESP32 Variants (ESP32-C3, ESP32-S2)

The library automatically detects and supports single-core ESP32 variants such as the ESP32-C3 and ESP32-S2. The decoder task's CPU core assignment and priority are automatically adjusted based on the `CONFIG_FREERTOS_UNICORE` configuration:

* **Single-core processors** (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3

* **Multi-core processors** (ESP32, ESP32-C5, ESP32-S3): Decoder task runs on core 1 with priority 2

This configuration ensures compatibility with single-core ESP32 variants that only have core 0 available, preventing boot crashes that would occur if the task were pinned to the non-existent core 1. Dual-core variants such as ESP32-C5 are handled as multi-core devices.

@copilot Pls review the details on the C5 Chip from expressif here - https://www.espressif.com/en/products/socs/esp32-c5

It is single core

Copilot · 2026-02-20T02:29:06Z

+;  '-DRAW_SIGNAL_DEBUG=true'   ; display raw received messages
+;  '-DMEMORY_DEBUG=true'   ; display memory usage information
+  '-DDEMOD_DEBUG=true'  ; display signal debug info
+	#'-DMY_DEVICES=true'		; subset of devices


The commented-out line at line 97 uses # for commenting, which is inconsistent with the INI file format used elsewhere in this file (; is the standard comment character). While PlatformIO accepts both, for consistency with the rest of the file, this should use ; instead of #.

Suggested change

#'-DMY_DEVICES=true' ; subset of devices

;'-DMY_DEVICES=true' ; subset of devices

Copilot · 2026-02-20T02:29:06Z

+# General options that are passed to the C and C++ compilers
+env.Append(CCFLAGS=["-Wno-implicit-function-declaration", "-Wno-error=implicit-function-declaration","-Wno-int-conversion"])


The compiler flags -Wno-implicit-function-declaration, -Wno-error=implicit-function-declaration, and -Wno-int-conversion suppress important warnings that could indicate real bugs (e.g., missing function declarations, incorrect type conversions). These flags are being applied globally to the build. Consider fixing the underlying issues in the code rather than suppressing these warnings, or at minimum, document why these suppressions are necessary for ESP32-C5 support specifically.

Suggested change

# General options that are passed to the C and C++ compilers

env.Append(CCFLAGS=["-Wno-implicit-function-declaration", "-Wno-error=implicit-function-declaration","-Wno-int-conversion"])

# General options that are passed to the C and C++ compilers.

# NOTE: The following warning-suppression flags are only applied for ESP32-C5

# builds. Some ESP32-C5 toolchain/SDK code triggers implicit-function-declaration

# and int-conversion warnings, which would otherwise break the build when treated

# as errors. Restricting these flags to ESP32-C5 avoids globally masking real

# issues in other environments.

board_config = env.BoardConfig()

mcu = board_config.get("build.mcu", "")

if mcu == "esp32c5":

env.Append(

CCFLAGS=[

"-Wno-implicit-function-declaration",

"-Wno-error=implicit-function-declaration",

"-Wno-int-conversion",

]

)

Copilot · 2026-02-20T02:29:07Z

 monitor_filters = esp32_exception_decoder
 ;platform = espressif32@3.5.0
 platform = espressif32@6.1.0
+extra_scripts = pre:update_link_flags.py


The extra_scripts directive is added to the [env] section, which means it applies globally to ALL build environments, not just esp32c5_cc1101. This could have unintended consequences for other ESP32 variants that may not need these warning suppressions. Consider moving this to the [env:esp32c5_cc1101] section instead if these flags are only needed for ESP32-C5 support.

Copilot · 2026-02-20T02:29:07Z

    defined(RF_MODULE_MOSI) && defined(RF_MODULE_CS)
 #  include <SPI.h>
-#  if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3
+#  if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3 || CONFIG_IDF_TARGET_ESP32C5


ESP32-C5 is grouped with ESP32-C3 and ESP32-S3 for FSPI usage, but according to Espressif documentation, ESP32-C5 may have different SPI peripheral configurations. Please verify that ESP32-C5 indeed uses FSPI like the C3 and S3 variants. If the documentation or SDK is unclear, this should be tested and documented.

Suggested change

# if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3 || CONFIG_IDF_TARGET_ESP32C5

// Use FSPI only on ESP32-C3 and ESP32-S3. ESP32-C5 is not grouped here

// because its SPI peripheral configuration may differ and must be verified.

# if CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32S3

Copilot · 2026-02-20T02:29:07Z

-#define rtl_433_Decoder_Priority 2
-#define rtl_433_Decoder_Core     1
+#ifdef CONFIG_FREERTOS_UNICORE
+#  define rtl_433_Decoder_Core     0


The priority is changed from 2 to 3 for single-core processors. Increasing the priority might affect system stability if other critical tasks run at lower priorities. Please document why the priority increase is necessary for single-core operation, or consider whether core 0 with priority 2 would be sufficient.

Suggested change

# define rtl_433_Decoder_Core 0

# define rtl_433_Decoder_Core 0

/*

* On single-core ESP32 builds we run the rtl_433 decoder task at priority 3

* instead of 2 to reduce the risk of losing samples when the CPU is shared

* with WiFi/Arduino and other medium-priority tasks on the same core.

*

* This was chosen empirically to keep decoding reliable under load. A higher

* priority means the decoder may preempt lower-priority work more often, so

* integrators who run additional critical tasks should review their task

* priorities and adjust if necessary.

*/

NorthernMan54 · 2026-02-20T03:06:55Z

Looks good

Question, why was src/rtl_433/decoder_util.c deleted ?

This reverts commit b4522ac.

…oder_util file

Samt43 · 2026-02-20T08:59:53Z

@NorthernMan54 finally i think it's more "decoder_utils copy" file that was more problematic (i suppose it's a mistake in the repo ? This create duplicate linking issues with decoder_utils.cpp file), fixed in my latest push.

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Copilot · 2026-02-20T09:14:16Z

+
+The library automatically detects and supports single-core ESP32 variants such as the ESP32-C3/5 and ESP32-S2. The decoder task's CPU core assignment and priority are automatically adjusted based on the `CONFIG_FREERTOS_UNICORE` configuration:
+
+* **Single-core processors** (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3


In the “Single-core processors” bullet list, ESP32-C5 is mentioned in the heading/paragraph but not included in the actual single-core list. This is inconsistent and may confuse readers about whether C5 is covered; add ESP32-C5 to the single-core bullet (or adjust the heading/text to match).

Suggested change

* **Single-core processors** (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3

* **Single-core processors** (ESP32-C3, ESP32-C5, ESP32-S2): Decoder task runs on core 0 with priority 3

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot AI and others added 5 commits February 19, 2026 14:35

Change ReadMe

d24ebf7

Add C5 to SPI init config

5534847

Add C5 config in ini file

b3ea958

remove duplicate file preventing compilation

b4522ac

Samt43 force-pushed the add_ESPC5_support branch from 000fa02 to b4522ac Compare February 19, 2026 13:37

Samt43 changed the title ~~Add espc5 support~~ Add esp32-c5 support Feb 19, 2026

NorthernMan54 requested a review from Copilot February 20, 2026 02:23

Copilot started reviewing on behalf of NorthernMan54 February 20, 2026 02:24 View session

Copilot AI reviewed Feb 20, 2026

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Samt43 added 2 commits February 20, 2026 09:56

Revert "remove duplicate file preventing compilation"

557c652

This reverts commit b4522ac.

remove decoder_utils copy file that create linking duplicate with dec…

2c2160b

…oder_util file

NorthernMan54 requested a review from Copilot February 20, 2026 09:09

Copilot started reviewing on behalf of NorthernMan54 February 20, 2026 09:09 View session

Copilot AI reviewed Feb 20, 2026

View reviewed changes

NorthernMan54 and others added 4 commits March 2, 2026 09:02

Update example/OOK_Receiver/platformio.ini

c20e241

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update example/OOK_Receiver/platformio.ini

fce8246

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update example/OOK_Receiver/platformio.ini

6648e60

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update example/OOK_Receiver/platformio.ini

1419819

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

	#'-DMY_DEVICES=true' ; subset of devices
	;'-DMY_DEVICES=true' ; subset of devices

		# General options that are passed to the C and C++ compilers
		env.Append(CCFLAGS=["-Wno-implicit-function-declaration", "-Wno-error=implicit-function-declaration","-Wno-int-conversion"])

-# General options that are passed to the C and C++ compilers
-env.Append(CCFLAGS=["-Wno-implicit-function-declaration", "-Wno-error=implicit-function-declaration","-Wno-int-conversion"])
+# General options that are passed to the C and C++ compilers.
+# NOTE: The following warning-suppression flags are only applied for ESP32-C5
+# builds. Some ESP32-C5 toolchain/SDK code triggers implicit-function-declaration
+# and int-conversion warnings, which would otherwise break the build when treated
+# as errors. Restricting these flags to ESP32-C5 avoids globally masking real
+# issues in other environments.
+board_config = env.BoardConfig()
+mcu = board_config.get("build.mcu", "")
+if mcu == "esp32c5":
+    env.Append(
+        CCFLAGS=[
+            "-Wno-implicit-function-declaration",
+            "-Wno-error=implicit-function-declaration",
+            "-Wno-int-conversion",
+        ]
+    )

-#  define rtl_433_Decoder_Core     0
+#  define rtl_433_Decoder_Core 0
+/*
+ * On single-core ESP32 builds we run the rtl_433 decoder task at priority 3
+ * instead of 2 to reduce the risk of losing samples when the CPU is shared
+ * with WiFi/Arduino and other medium-priority tasks on the same core.
+ *
+ * This was chosen empirically to keep decoding reliable under load. A higher
+ * priority means the decoder may preempt lower-priority work more often, so
+ * integrators who run additional critical tasks should review their task
+ * priorities and adjust if necessary.
+ */


		The library automatically detects and supports single-core ESP32 variants such as the ESP32-C3/5 and ESP32-S2. The decoder task's CPU core assignment and priority are automatically adjusted based on the `CONFIG_FREERTOS_UNICORE` configuration:

		* Single-core processors (ESP32-C3, ESP32-S2): Decoder task runs on core 0 with priority 3

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Samt43 commented Feb 19, 2026

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