ESP32 Forum

Has anyone received clarification on whether the ESP32-E22 supports custom ESP-IDF firmware?

I'm designing a product that pairs an ESP32-P4 with an ESP32-E22. The E22 would handle Wi-Fi connectivity, OTA updates, and cloud telemetry — running custom application firmware built with ESP-IDF (FreeRTOS tasks, HTTP client, NVS storage, UART communication with the P4 host).

We currently have working firmware targeting the ESP32-C6 as a development stand-in, but the C6 is not in our final hardware design — the board is being designed around the E22 specifically for its Wi-Fi 6E capability and the P4+E22 pairing is an architectural decision that's already been made. Swapping in a C6 would require a board respin that we want to avoid.

I have five specific questions before finalizing our PCB design:

1. Can the ESP32-E22 run custom ESP-IDF application firmware (our own app_main, FreeRTOS tasks, etc.), or is it restricted to operating as a radio co-processor driven by a host via PCIe/SDIO?

2. Does the E22 expose UART peripherals that can be used for custom inter-chip communication (921600 baud IPC with the P4), or are only PCIe 2.1 and SDIO 3.0 available as host interfaces?

3. If the E22 does support custom firmware, is the ESP-IDF target and peripheral API compatible with C6 code, or would a port be required?

4. I've seen a statement attributed to Espressif sales indicating the E22 "operates only in slave mode and does not support secondary development." Can anyone confirm whether this is still accurate, or whether custom firmware development will be supported?

5. What is the expected timeline for general availability of the E22, and when will ESP-IDF SDK support and documentation be publicly available?

If the E22 truly cannot run custom application firmware, we'll need to restructure our architecture to drive the E22 as a host-managed radio from the P4 side over PCIe/SDIO, which is a significant redesign. Any firsthand experience or official clarification would be really helpful.

well, I don't want to add salt to the wound, but who took the architectural decision without having an answer to these basic questions...
I look around for some engineering documents, but couldn't find anythng beside marketing materials. I'm also curious about this communication "beast".
Maybe someone from espressif staff can bring some light here.

Thank you. I’m still looking for an official technical clarification from Espressif, as this impacts an active PCB design decision.
Could Espressif please confirm, explicitly, whether the ESP32-E22:

can run custom ESP-IDF application firmware, or
is limited to host-managed radio/coproc operation only.

In particular, we need confirmation on:

Whether custom firmware (app_main, FreeRTOS tasks, NVS, networking, etc.) is supported
Whether UART is available for custom inter-chip communication, or whether only PCIe / SDIO are supported
Whether a public ESP-IDF target / SDK / documentation will be provided
Whether the statement that the E22 “does not support secondary development” is currently accurate
Expected timing for documentation, SDK support, and general availability

Because this directly determines whether we proceed with this architecture or redesign it, we would appreciate a clear technical answer rather than a high-level product description.
Thank you.

I'd suggest contacting sales@espressif.com for this, as I don't think the engineers here have the info to say anything about this. Lacking evidence to the contrary, I think it would be safest to assume the chip cannot work stand-alone, however.