[ESP32-S2-Kaluga-1 Review] VII. Discussion on psram (this thing is just for show!)

RCSN

[ESP32-S2-Kaluga-1 Review] VII. Discussion on psram (this thing is just for show!) [Copy link]

 

Originally I thought that Espressif's esp32s2, a new USB peripheral, has been in development for a year, and the device is only being maintained by tinyusb, while the host has not been released yet. This doesn't matter, so I can just wait.

After using some of the GUI functions posted above, the author wanted to add an AP+TCP server to play with it, so he added the WiFi-related initialization

I found the following error during compilation, indicating that the internal dram space is insufficient. The main reason is that the WiFi-related initialization occupies too many uninitialized global variables, but they must be used.

But after checking heap_size, I found that there is more than 2M space after adding psram.

Well, since the internal RAM space is not enough, I can move the related bss segments, wifi, lwip and other variables to Psram. Menuconfig also supports it, so let's do it and enable the following two.

RCSN

Then compile again, oh wow, sure enough, it reports an error again, it's really awesome. It prompts that the bss head and tail addresses of psram are not defined.

Search globally for CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY and I found that enabling the above two functions is indeed linked to psram in ld, but it is esp32's

Oh, the feature that allows .bss sections to be placed in off-chip memory is only available for esp32, not esp32s2.

RCSN

Oh, look at the esternal-ram.rst file, it is only applicable to esp32

RCSN

You said that this is a castrated version of esp32s2, right? Well, it is not castrated, at least it gives you an external Psram. Since psram can be expanded, it is not hardware castration, at least the support function of esp32s2 for external memory expansion is also improved. The usb function is already very annoying, and this function is not difficult to develop, and it is easy to copy. Why not support it? It is a mysterious operation. I can't understand it.

freebsder

The client doesn't like your in-depth review the most! You've done so many things that you can't even hide them!

lcofjp

Awesome...

okhxyyo

ESP32-S2-Kaluga-1 development board review
Summary post: https://en.eeworld.com/bbs/thread-1134201-1-1.html

liangfeng2001

I also encountered the same problem, which means that esp32s2 cannot use its configured external PSRAM?