jpmschweitzerandClaude Fable 5
cb5826e02b
Root cause (verified against our exact IDF tree, not the community guess): the "258" in "sdio_write_task: Failed to send data: 258" is NOT a timeout (that is 263). 258 = 0x102 = ESP_ERR_INVALID_ARG. On the ESP32-P4, block- mode CMD53 writes require the SOURCE buffer to be 64-byte (cache-line) aligned; the IDF sdmmc driver rejects a misaligned source with INVALID_ARG BEFORE any bus activity. esp_hosts write loop then declares "Unrecoverable host sdio state" and reboots the whole P4. The audio TX payload is not 64-aligned, so streaming mic audio wedged on the very FIRST frame (which is exactly what we saw: listening -> instant Failed to send -> reboot). This also explains why buffer/queue/clock/retry tuning all did nothing: the write never reached the bus. And why our symptom was instant, not after ~100 writes (the community block-mode-desync theory) — it is the first misaligned buffer, every time. Fix: vendored esp_hosted 2.12.11 as an editable local component (overrides the registry copy) and bounce a misaligned TX payload through one aligned DMA scratch buffer in hosted_sdio_write_block (port_esp_hosted_host_sdio.c). TX is serialized by the bus lock so a single static bounce buffer is safe; freed in hosted_sdio_deinit. Host-only change — no C6 reflash. VERIFIED ON HARDWARE (autonomous self-test): 40s of continuous mic-audio upstream streaming — the traffic that previously wedged on the first frame — ran clean, zero timeouts, zero reboots. A guarded SDIO_TX_SELFTEST harness is kept (compiled out) for future SDIO stress testing. Credit: root cause + patch designed via multi-agent investigation; the precise 258=INVALID_ARG decode (correcting the upstream community timeout assumption) came from checking our actual esp_err.h. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
ESP-Hosted GPIO Control Example
This example demonstrates how to use the ESP-Hosted solution to control the GPIOs of the slave (co-processor) from the host MCU.
How to Use
Feature Switch
Feature can be controlled at Host and Slave using CONFIG_ESP_HOSTED_ENABLE_GPIO_EXPANDER option.
It is by default disabled at slave.
Slave Configuration:
* The firmware flashed on the slave board must have the GPIO RPC feature enabled. In the slave's idf.py menuconfig, set the following:
(Top) → Example Configuration ---> [*] Enable GPIO Expander support (host can control slave GPIOs)
This corresponds to the CONFIG_ESP_HOSTED_ENABLE_GPIO_EXPANDER=y option.
Build and Flash
-
Slave
- Slave build & flashed with above config
-
Host:
- Set your target board (e.g.,
idf.py set-target esp32p4). - Build and flash the project:
idf.py -p <host_port> build flash monitor.
- Set your target board (e.g.,
The host application will:
- Initialize the ESP-Hosted transport.
- Configure a specific GPIO pin on the slave as an output.
- Toggle the GPIO level (HIGH and LOW) every second.
- After a few toggles, it will reconfigure the same GPIO as an input.
- Read and print the GPIO level.
You can connect an LED to the specified GPIO on the slave board to visually verify the output functionality.