ESP32-S2-MINI-1, EDMA, PSRAM and cameras

[trusley_mike]

We have used the excellent, and small, ESP32-S2-MINI-1 in three products that require wifi but not Bluetooth.

We are developing a fourth product with a camera and we would like to stick to the same module.

The ESP32-S2-MINI-1 datasheet includes references to a "camera interface" and to a "Camera for Video Streaming" application.

However, streaming requires PSRAM - like the many different ESP32-CAM boards - some of which use Espressif PSRAM and some of which use the AP Memory APS6404L-3SQR.

Figure 1 of the ESP32-S2 SOC Hardware Design Guidelines shows PSRAM connected to dedicated lines (SPICLK etc.) on pins 29 to 35 of the S2.

My concern is that Figure 5 of the ESP32-S2-MINI-1 datasheet shows that none of these lines are connected on the module.

I appreciate that camera support for external RAM is via I2S and EDMA - and that EDMA development in IDF 4.3 Beta is not yet complete for the S2.

viewtopic.php?t=14532

I am also aware that Espressif have said: "The driver of EDMA is under development and need more time to finish and test it."

My questions are specific to the ESP32-S2-MINI-1 module.

Assuming a driver becomes available for EDMA on the S2:

1) Will the ESP32-S2-MINI-1 be able to support external PSRAM required for video streaming?

2) To which lines should the PSRAM be connected, those labelled "FSPIx"?

3) Is there any estimate as to when EDMA support will be available?

4) Should we look to using an alternative module to be on the safe side?

[lbernstone]

The pins needed to connect an external psram are not included on the mini. There are however, modules with 2MB psram integrated in the chip itself. https://www.mouser.com/ProductDetail/Es ... 2B9A%3D%3D

[trusley_mike]

Iberstone

Thank you for your response.

As you say, the Espressif web site:

https://www.espressif.com/en/products/modules

DOES show a version of the ESP32-S2-MINI-1 with 2MB of PSRAM but, as yet, the datasheet has no reference to PSRAM.

The good news is that the version with the ESP32-S2FN4R2 SOC should have 2MB PSRAM - as indicated by the "R2" at the end of the part name.

The bad news is that it is at the sampling stage and no-one has any.

I will put in a back-order with Mouser and see what turns up. My experience is that estimated delivery dates on Mouser (and DigiKey) are a little optimistic for new Espressif parts. I got a batch of the modules without PSRAM from SOS Electronics in Slovakia - they were very efficient on delivery but they don't have the PSRAM version!

Thanks again for the pointer.