SIM900 GPRS Shield power consumption 12mA instead of 1.5mA

#1

I’m using this module:

763×436

I’ve managed to reduce the power consumption to 9,55mA after removing the LED’s on the board and using the following codesnippet, but I’m confused about the power consumption.

void SIM900power()
    // software equivalent of pressing the GSM shield "power" button
    {
      digitalWrite(9, HIGH);
      delay(1000);
      digitalWrite(9, LOW);
      delay(5000);
    }

Even when I use the sleep command AT+CSCLK=2 it’s the same. I’m not sure, what consumes power on the board anymore, but is it maybe the low-dropout voltage regulator MIC29302WU?

I’m powering the Shield via the VBat with a 3,7 2500mAh Lipo battery. Can somebody else confirm, that the power is not 1.5mA, when the shield is powered off for the same shield?

#2

Some more pictures, which illustrate my setup:

20200609_145147
20200609_1451473264×1836 1.86 MB

20200609_170656
20200609_1706561836×3264 1.13 MB

After some more research, I’m pretty sure the low-dropout voltage regulator MIC29302WU
is the culprit, but I’m not sure, if I can just remove it.

#3

Seems the module doesn’t work anymore, when you remove the LDO. So I don’t recommened doing that. I’m using the SIM800L now. I reach the desired current consumption with this module in deep sleep. AT+CFUN=0 followed by AT+CSCLK=2 gives me a current consumption around 0,70mA, which sometimes rises up to 1.13mA.