ESP-12F Power supply issues only when using AT Firmware??

[sebastian.heyn]

Hi all,

I designed a custom PCB for a ESP-12 module. However I think I am facing some PSU issues.

the PSU is 5V and The PCB has a LF33 (and external components)

After booting, the ESP states: "ready" then "Wifi disconnect"

The point is, If I add capacitors to the 3.3V lane, the behaviour is more stable. But it varies between each ESP-12 module. And also what I noticed: This unstable behaviour is only observed when using the AT firmware.

I was able to reporduce the behaviour using a Wemos D1 Mini board. It works stable, using the delivered firmware, however when flashing the latest AT firmware to the device, it behaves unstable (increasing ping times, sometimes no connection) - When adding a capacitor to the 3.3V of the wemos board, it is stable again.

Is the AT firmware transient load higher? If yes, why? and is there a configuration parameter, that I can decrease peak power consumption?

Also, is the ESP32 more stable than that? Are there any modules that include a 5V to 3.3V line converter that handles the AT firmware?