Adding PSRAM to the ESP32-S3-WROOM-1U-H4

[jtekmagic]

I need an ESP32 module with an ambient max temp of 105c. Since there appears to be no ESP32-S3-WROOM modules available with a max temp of 105c that support internal PSRAM, can PSRAM be added externally by using this schematic checklist - https://docs.espressif.com/projects/esp ... v3-vddsdio?

Are there any precaution I should take?

Thx

[Sprite]

I don't think you can do that, as I don't think the GPIOs you need for that are available on the module pads.

[jtekmagic]

Hey Sprite when you say "I don't think you can do that", can you be a bit more specific?

I know the ESP32-S3 GPIOs pin 27 - 32 are the pins that interface with both flash and PSRAM on the ESP32-S3 modules and I know these pins are not available for external use with the ESP32-S3 modules. But the modules do support GPIOs pins 9-14 and these pins can be define with the same pin functions as GPIOs 27-32. So, if GPIO pins 9-14 can be defined with functions SPIHD, SPIWP, SPICS, SPICLK, SPIQ, SPID in the same way GPIO pins 27-32 are defined, why can't GPIO pins 9-14 perform the functions as GPIO pin 27-32 and be used to support PSRAM?

[Sprite]

Hey Sprite when you say "I don't think you can do that", can you be a bit more specific?

I know the ESP32-S3 GPIOs pin 27 - 32 are the pins that interface with both flash and PSRAM on the ESP32-S3 modules and I know these pins are not available for external use with the ESP32-S3 modules. But the modules do support GPIOs pins 9-14 and these pins can be define with the same pin functions as GPIOs 27-32. So, if GPIO pins 9-14 can be defined with functions SPIHD, SPIWP, SPICS, SPICLK, SPIQ, SPID in the same way GPIO pins 27-32 are defined, why can't GPIO pins 9-14 perform the functions as GPIO pin 27-32 and be used to support PSRAM?

PSRAM and flash share most of their pins, meaning the PSRAM needs to be on the pins the flash is connected to as well. If you want to add external PSRAM, you can use eFuses to change the pins the flash are on to outside pins and the PSRAM pins will follow. However, you would not be able to use the internal flash anymore as it'll be on the 'wrong' pins.

Might be easier to poke the sales division (sales@espressif.com) to see if there's any possibility of producing a 105C module with psram,