Board improvement

[kaizen75]

I am currently working on a battery powered sensor node. For data storage I have attached a W25Q32 EEPROM to the board. The EEPROM works fine, but when I switch to standby mode on the STM32 using the HAL_PWR_EnterSTANDBYMode() function. The EEPROM still consumes 1-2mA which is very much higher than the uA level current it should do.
The problem lies in the fact that PA4 (CS) goes low when the STM32 goes into standby and therefore /CS for the EEPROM is active which causes the chip to become active and consume 1-2mA. I found the solution to be to place a pullup resistor of 100k-1M between pin 1 (/CS) and pin 8 (3V3). In my case the current went down to 3uA. Maybe it is a board improvement to include unpopulated pads for this resistor just like there are unpopulated pads for the decoupling capacitor for the EEPROM on the bottom side of your board.