Meaning of Low Level Trigger

I am running a device on battery with ESP32. In low power mode, the device consumes around 0.5mA. Everything is working fine.

I power up ESP32 using 5V pin and the below module which has a integrated Boost convertor to 5V.
But, since the current consumption of the device in low power mode is low, the charging module powers off after 30 seconds.

I checked the description and found this,

  • ★ MCU users, if you accept a small load KEY can be connected to the microcontroller about 20s to provide a low level allows the module to continue working. Trigger mode: low level trigger (ground)

Can someone explain what it says. I tried soldering the key pin to the ground, the device does not even start. But when I touch the ground to the key pin and take it away, it stats again.

Can someone tell me how I can keep the device active using the ESP32?

Sounds like a very bad translation.

I would assume that you must pull that pin low for about 20 s prior to go to sleep. Maybe a constant connection to GND deactivates that functionality but the datasheet should tell you more. If you don't have a datasheet, throw that one away and get device that has documentation.

Hey @pylon. Thanks for your time.

Apparently, I found out that f I connect the connect the key to the ground once every 20 seconds, the device keeps running. But, do you know if I can achieve that with any of the GPIO pins of an arduino or ESP32?

Thank you for your time. I found no data sheet. These are the only set of instruction I found on it were as below

Blockquote

  • MCU users, if you accept a small load KEY can be connected to the microcontroller about 20s to provide a low level allows the module to continue working. Trigger mode: low level trigger (ground)
  • 4 in 1 Charging / Discharging / Lithium Battery Protection / Battery Level Indicator Module. Lithium battery protection function: over-current, overvoltage, over-temperature, short circuit protection.
  • In discharge mode (The charging mode KEY function is invalid), trigger the KEY port once to open the output continuously trigger the KEY port twice to close the output.
  • The first time the load is connected, the output is automatically turned on. If the load is less than 50MA, the output will be automatically turned off after 30 seconds if the load is greater than 50MA, the output will be automatically turned on.
  • Allow discharge while charging. (Note: At this time output voltage 4.7 / 5V)

Blockquote

#7 note (6th pad)
The uC or switch needs to manage the signaling ... likely before sleep.

It is unclear if the uC can do this in setup()

  • MCU users, if you accept a small load KEY can be connected to the microcontroller about 20s to provide a low level allows the module to continue working. Trigger mode: low level trigger (ground)

Calling something like this periodically may work:

void tweakPinLow(const byte pin){
  unsigned long interval = 10000UL;
  static unsigned long last = -interval;
  static bool isTweaking = false;
  unsigned long now = millis();
  if(now - last >= interval){
    last = now;
    switch(pinState){
        case false:
           pinMode(pin,OUTPUT);
           digitalWrite(pin,LOW);
           interval = 20;
           pinState = true;
           break;
        case true:
           pinMode(pin,INPUT);  // tri-state the pin
           interval = 15000;
           pinState = false;
           break;
    } // switch
  } // if
} 

Hello @DaveX, @mrburnette and @pylon . Thank you again for your time and help.

So, would you know of any way of keeping the cycle running when the ESP32 is in low power mode? Because in the night I run the device only once every hour or two.

Thanks in advance. I appreciate your help here.

What? Connecting to ground? Yes, define the pin as output and write low to it.

You must wake it every ten seconds (or so) and pull the pin low for a few milliseconds and go to sleep again.

1 Like

Argh . . . this is a task for a lowly 555 timer.

If external circuitry is no problem, of course a 555 can do that.

A standard 555 timer is NOT a low-power device!

... and I did not say "standard"

For all readers:

my longtime acquaintance westfm is however correct:

But, in this post (and others) I will often use shortcut terms to reference parts; so "555" means the Op is responsible for researching the component and only the Op can make a decision on the component and the demand on the power-budget (translate to battery life.)

If I use "PNP" or "NPN" then I expect my response to only be used by Op to limit research criterion; thus it should be a gentle nudge in a direction of research.

In these forum pages, I routinely find that frustration on the part of the author has limited their ability to do critical (problem solving) activities. Sometimes, the Op simply has not used the Internet search engine correctly - it happens all too often.

Before I get off my soapbox, software (sketch, libraries) are often not the appropriate solution to an issue: hardware is still king for many interfacing issues.

  • Ray

Oh, you meant an EXHAULTED 555!
The CSS555 does 5uA...
http://www.customsiliconsolutions.com/downloads/Revised%20Standard%20products/CSS555_Spec_2.pdf

TI has some near little timer chips that do 35nA (not sure whether they'd work without additional handling. The "on" times don't seem very programmable.)

That device appears to have the functionality of a powerbank and is primarily intended to be used as a charger for other devices such as smartphones etc. hence the auto shutoff which, in your case, is unwanted. It is not really suitable for the continuous powering of a low current device.

If you do, however, want to continue using that device in the role of a low current power supply, search this forum for the keyword "powerbank" . You'll see all sorts of tricks for keeping them running with small load applications.

Here is just one of many: Powering the arduino nano with a Power bank

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.