Deep sleep high current on Atom
oklab-ka last edited by
I'm testing deep sleep current for an Atom project. Atom starts, current is about 50mA. In deep sleep current drops to less than 1mA, which is what I expect. Atom awakes after 30 seconds to do its regular job, then goes to deep sleep again. However, this time (and all subsequent times) deep sleep current is about 11mA. When I press the reset button immediately after power on, the first deep sleep is also 11mA. I can also see a difference in the active current in the order of 11mA. There are no units connected. Whatever I do, disable Serial, I2C, Display, isolate GPIOs or not, there is no effect.
Unfortunately M5Stack doesn't provide schematics for the Atom, just a block diagram which misses out a lot of details.
Any ideas? Should I remove the RGB Led or the IR transmitter. My best guess is it is the FTDI chip coming out of sleep mode due to some fluctuation on the TX/RX lines. But without schematics I cannot do much. What I found on FTDI is something like 8-15mA, depending on the chip type. The only one in SSOP20 package is FT231X. Any help welcome. Below 1mA is good, but 11mA deep sleep current is a nightmare. There are many questions on the deep sleep power issue and I'd be very glad if M5 could do something to improve this ...
felmue last edited by
just curious, are you powering M5Atom from 5 V (e.g. USB) or 3.3 V?
oklab-ka last edited by oklab-ka
@felmue Tried both. 3.3V has a bit higher current. Strange, if there's just an LDO (guessing - no schematics!).
Also removed IR and RGB LEDs. Tried with Arduino and Espressif IDF deep-sleep example. No success. NodeMCU with Wroom32 is kind of OK (1.6mA), by the way. But mechanically too large ...