ESP32 Forum

Hello and thanks in advance

I was trying to understand why I can't add my external PSRAM working with my ESP32-pico-d4 chip

I'm using ESP-IDF v4.0 with eclipse. My PSRAM chip is LY68L6400 and is connected as described below:

PSRAM ESP32-PICO-D4
CS IO17 (pin 27)
SCLK CLK (pin 31)
SIO0/SI SD0
SIO1/SO SD1
SIO2 SD2
SIO3 SD3

The CS is configured in the menuconfig

In the spiram_psram.c file I see the same configuration I have:
but after loading anything to the chip I get:


I (225) psram: This chip is ESP32-PICO
E (230) cpu_start: Failed to init external RAM!
abort() was called at PC 0x4008136e on core 0

My PSRAM chip is connected to the VDD_SDIO and the voltage is 3.3V (measured)

With my oscilloscope, I can see signals in all pins except SIO3

If anyone can help me a bit I'll be very thanked because I'm very stuck with that.

Thanks in advance, Julian

Maybe not useful for you...

But, I had similar problem few months back.

Turns out I was using pin 9 for CLK.


Following change worked for me...

If you go to $IDF_PATH/components/esp32/spiram_psram.c

There is a define: I changed this to
...and it worked.

Maybe similar change you are missing?

ESP_Vikram wrote: ↑

Thu Feb 13, 2020 3:54 pm

Maybe not useful for you...

But, I had similar problem few months back.

Turns out I was using pin 9 for CLK.


Following change worked for me...

If you go to $IDF_PATH/components/esp32/spiram_psram.c

There is a define:

Code: Select all

#define PICO_PSRAM_CLK_IO          6

I changed this to

Code: Select all

#define PICO_PSRAM_CLK_IO          9

...and it worked.

Maybe similar change you are missing?

Hello Vikram, thanks for your answer

I have the PSRAM SCLK pin connected to the CLK pin of the ESP32-PICO-D4 which is number GPIO6. It seems in my case I'm using the default PICO_PSRAM_CLK_IO

Thanks again, Julian

ESP_Vikram wrote: ↑

Thu Feb 13, 2020 3:54 pm

Maybe not useful for you...

But, I had similar problem few months back.

Turns out I was using pin 9 for CLK.


Following change worked for me...

If you go to $IDF_PATH/components/esp32/spiram_psram.c

There is a define:

Code: Select all

#define PICO_PSRAM_CLK_IO          6

I changed this to

Code: Select all

#define PICO_PSRAM_CLK_IO          9

...and it worked.

Maybe similar change you are missing?

Can you Vikram please tell me if the rest of your pines was connected as I did?
Also, did you use IDF 4.0?
Finally, did you configure something else than turn on SPI RAM on the menuconfig and set the CS pin?

Thanks again