I've read in various sources that in deep sleep mode, current consumption should be somewhere between 10μA and 88μA - but in my tests, deep sleep current doesn't get below 2.6mA. Which is 30-250x higher than advertised.
I tested by placing a 1 ohm resistor in series with the power supply and measuring the current across it. I've eliminated pretty much every other component in my circuit, turned off the status LED, and so on.
I've tested a variety of things trying to reduce this measurement, without success:
* WeMos D1 Mini (ESP-12F module + rt9013 regulator + USB-RS232 + nodemcu reset circuit)
* Plain ESP-12F (pushbutton reset circuit + ams1117-3.3 regulator)
* Powering with 5v via regulator
* Powering with 3.3v ignoring regulator
* Physically removing ESP-12F module's status LED
* Disconnecting txd and rxd
* Adding a 10k pull up to CSO
* Adding 10k pull up / down resistors to unused pins
None of these tests has got the voltage across the resistor below 2.6mV.
Basically, the only things I can think of left to do are (a) remove the regulators entirely, in case they draw current when only their output pin is powered; (b) replace the SPI flash on the ESP-12F with the flash from a module with known good deep sleep performance; or (c) convert my program from arduino to lua or nodemcu in case that makes any difference.
If anyone has any experience getting sub-100μA current consumption, if you could post some details (the language, module type, flash type etc) or any other details of what you needed to do to get that current consumption, that would be great