Hey guys, Just received my MPW2 chips today and was stuck on the Winbond SRAM error and noticed how a common suggestion was insufficient power. So spent some time going through the HAT schematic and Nucleo144 Datasheet (UM1974) According to the HAT's Design the entire board is powered of one pin from the Nucleo that is CN11 pin18. And according to the data on page 21-23, the board supports a maximum of 300mA and exceeding that causes the board to shut down or malfunction. One solution that I can think of is Shorting J12 on the HAT and connecting a third micro USB cable (on the HAT to an external power supply like a mobile charger) for powering the entire HAT ensuring a reliable 5V supply. I might be wrong about this and it would be great if @Matt Venn @Tim Edwards @proppy could provide some inputs on this idea.

Another alternative is to use JP3 on the nucleo board so that it doesn't get power from the ST-LINK and instead supply power via Vin on r the board. This would allow up to 800mA at 7V. Trying to find where Vin comes from...

I also feel issue in single power pin connection between nucleo and caravel hat is creating issue. My system working well without any issue for past 3 day's https://open-source-silicon.slack.com/archives/C03UVJCTR8U/p1674205852607689?thread_ts=1674149630.166839&cid=C03UVJCTR8U

Did you change the configuration on JP3? I tried an external power supply and am stuck with this error

*** flashing Caravel
 
Caravel data:
   mfg        = 0000
   product    = 00
   project ID = 00000000
 
Resetting Flash...
status = 0x00
 
JEDEC = b'000000'
Winbond SRAM not found

Your case, even nulceo <=> caravel SPI access is not clean. you can try with changing caravel die board. Previously i tried even with external Vin (10V) with changing JP3 connectivity and does not helped.

I tried with another powered USB hub and some better cables and got the same result as before.

I started documenting those issue here: https://github.com/efabless/caravel_board/issues/23 @Matthew Guthaus @Yatharth Agarwal it'd be great to get more perspective on this.