with the ESP32-Pico-D4
(Rev1) we did connect and drive external PSRAM here in this thread well. this helped few maker to forward the PSRAM using with pico i think.
with the ESP32-Pico-V3
, which has 4MB eMbedded Flash like the D4, from data sheet there is a compatible official note but also restriction
- None of the embedded flash data pins are connected externally on ESP32-PICO-V3. These are connected
internally to GPIO16, GPIO17, GPIO18, and GPIO23.
- It is not possible to connect an external PSRAM chip to ESP32-PICO-V3.
with the ESP32-Pico-V3-02
, which has 8 MB eMbedded Flash and 2MB eMbedded PSRAM from data sheet there is a compatible official note but also restriction
-For security purposes, flash data pins DI, DO, /HOLD, and /WP and PSRAM data pins SI/SIO0, SO/SIO1,
SIO2, SIO3 are not led out.
-It is not possible to connect an external PSRAM chip to ESP32-PICO-V3-02 and ESP32-PICO-V3.
cause i liked the pico from begin i created this thread in '17 and i want share few further infos and success in this what i did in this direction. i spend a few more time and further efforts in this "Pico Theme" last time again also SD Card support and other few goodies.
there is an unofficial custom engineering work
with a "PSRAMBANK" which include not one but 8*32Mbit / 8*64Mbit PSRAM chips and successfull tested with Pico-D4(V1), Pico-V3 and Pico-V3-02 of Picos. there are few code line need to be change and few codeline adds and modifications in the ESP-IDF, Arduino-esp32, µpython port and the CircuitPython. it is a custom work and effort need for this who wants this have to run.
just in time i spend little time further again in a small Pico(v3)-Stamp with PSRAM and SD Card and an ESP32-C3-Stick with PSRAM cause the V3-02 has included eMbeddd PSRAM - so my focus is more to pimp the Pico-V3 finally now that i get all futures which ESP32-ECO-V3 Benefits to use it in my designs.
Note, the ESP32-C3 is a new one from espressif and was mentioded in the espressif news and have nothing to do with the Pico's but with the PSRAMBANK work i did . The mentioned PSRAMBANK has sizefactor same like the ESP32-PICO-D4 Kit, it was created for the Kit and usefull for own testings with several MCU'S. the second version is for the espressif ESP32-Sx mini serie, which the ESP32-C3 is also included.
More about the engineering PSRAMBANK pcb
not sure but i think i will post the basics in the showroom later time, if there is any interest in this perhaps with few more infos.
PSRAM basicly work for me is done here in this thread for Picos and it works like it should.
Note, the PSRAMBANK is more or less non ESP-IDF -standard and not official and custom work, also the extended use of psram in the picos with restrictions, which officially is not supported, it is a hard work and not a matter of course. it was an attempt that was successful for my needs. everything else is then in the showroom thread later at need. i enjoyed the softening the restriction like i allways do in the phase of doing this