ESP32 Forum

Hi everyone,

The ESP-IDF Programming Guide says the ESP-PSRAM chip connections for the ESP32D2W* chips are "TBD".

https://esp-idf.readthedocs.io/en/lates ... l-ram.html

Has it been determined yet? If so, what are the connections? Or, where can I find them? And, is it possible to create a SWAP on external?

Also, I see a number of ESP32 fans are using Eclipse and others using PlatformIO (Arduino too). I tried these and they seem to do what I need (Arduino a bit limited, but fine). Right now, I am installing MicroPython on an ESP32 chip. Would like to hear any input from others what they thought about that (or why not if you think it is a waste of time).

Thanks

The D2W is a chip that has the SPI-FLASH put inside the same package as the ESP32 chip itself.
This is somewhat strange, because in this case the flash chip is a separsate die inside the package, where the connections that you normally do externally are wired with bond wires inside the package.
Therefore connecting external SPIRAM which uses the same pins plus some extra as the Flash, it's somewhat difficult.
Since it's only 16Mbit flash (2MB), it can be a bit small for most apps, and I don't see this type out there a lot.

I see mostly modules, and PICO-D4 packages. Modules usually use the D0WD chip, D0WD chiponly have the ESP chip in the package. External flash and RAM can be connected much more freely.
The PICO-D4 is a bit different, because it has 4MB flash inside, as well as the 40MHz oscillator and some passive components for the antenna pin. Therefore it has everything inside. For this I believe that external RAM can be connected with relative ease.

Below pic is the insides of a PICO. You can see the ESP32 chip (big grey square), with the flash chip glued on top, as well as the passives and the oscillator.
The D2W chip has the flash attached the same way.

Fun fact: On the ESP32 chip, the marked darker area is actually the CPU, WIFI and BT hardware, registers and Low power coprocessor, in that tiny area. The rest of the CHIP is the internal 512kB RAM