ESP_Sprite wrote:I'm not quite convinced of that level shifter... at 1.8V, it has a throughput of 60MBPS, which is less than the 80MHz and dangerously close to the 40MHz the ESP32 can use as clock speeds, Also, I'm not entirely sure if the auto-direction-switching is enough for the way we use SPI.
i am now too not more sure, does the converter can drive so fast the lines
and there was other thinking too,
why we use 1.8 flash ..
there can be answeres
- cause we have just in time only 1.8 psram
- cause 3.3 flash to much noise
- cause 3.3 flash V^2 -> 4 times the energy - and more power - and this breaks in / off
ESP_Sprite wrote:Official answer: Get one of our devkits or modules that have integrated PSRAM, we can guarantee the hardware qualifications of those.
the only one that include psram - wrover modules - are just in time sold out
the wrover kits - there is a possible way to become one with wrover modul mounted and SoC Rev1 and psram
ESP_Sprite wrote:Unofficial answer (more like a suggestion; nothing guaranteed): The way we experimented with PSRAM before the modules with them on it were ready is to take a devkit, remove the 3.3V flash and replace it with 1.8V flash, then solder the PSRAM chip on top of it, deadbug style, with the CLK and CS pins floating and the rest connected to the flash chip; we use the fact that the psram chip has the same pinout as a normal flash chip. We then used thin wiring to wire the CS and CLK pins up, made sure to wire up the bootstrap pin was set in such a way that VDD_SIO is 1.8V (and the flash is connected to VDD_SIO), and that was enough to make it work; no level converters needed.
https://twitter.com/eMbeddedHome/status ... 9196505088
exactly this was the first thinking
cause i had no 1.8 flash -
i was start to try this with level converting
- resistor -( to to to slow )
- tbx0108 - i think perhabs not fast enough
now i get this weekend 128MiB 1.8 flash, 64MiB 1.8 psram, ( 32MiB 1.8 psram already here )
- pimp the wroom32 ( DevKitC ) like first thinking and you mentioned ( remove 3.3 flash, solder 1.8 flash, packagepack 1.8 psram, cs(16, pull_up vdd_sdio 1.8 ) and clk(17) ..... and bootstrap MTDI pulled_up 3.3
there is only the test, that the boot is ok with this hardware setup as base -
( cause DevKitC is SoC Rev0 there are then distrikes in psram - but this is ok )
txs, i know you are very stress and under pressure just at time - so - thank you for the time frame and help!
I give here now also a little peace and try this steps after receive the 1.8er flash
sure, 32MiB there are then here too, if i fall in next prob with 128MiB.
i will rewrite the result then .
( please check R9 in wrover modules - the info is missing in reference and guide that is already done boostrap 1.8 on the modul )