I have been working with the MicroView controller trying to reduce as much power in power-down mode as possible. I’m using the LowPower library and have successfully turned off all the timers, ADC, BOD, TWI, SPI, USART, etc. With everything turned off on the ATMega328P controller I should be drawing a mere 10uA, but have not been able to get that low (running around 190uA). I’ve discovered that the 2 voltage regulators on the microview board are what is drawing the remaining power even in power-down mode. Having read thru the datasheets for both of the voltage regulators, it appears I should be able to disable each of them. The SPX3819 voltage regulator states on page 8 of the datasheet to disable the regulator, EN < 0.4V. So I tried disconecting the VIN to that lug of the regulator by scratching the PCB run from VIN to EN of the regulator. This is not producing the expected results as the MicroView is now giving some eratic results on the OLED and my program is not functioning as expected. Am I missing something here or can’t this be done as I described above? Also, for the MIC5205 voltage regulator, it appears that I should be able to disable this by using code in the arduino program. From your MicroView schematic, Digital pin 4 appears to be connected to the EN lug of the MIC5205 voltage regulator. I added 2 lines to my program setting Pin 4 as output (pinMode(4, OUTPUT)
and then set to low (digitalWrite(4, LOW);). This may be disabling this voltage regulator but I wasn’t able to see a reduction in the current draw. Is this the correct way to disable the MIC5205 voltage regulator? Your help in bypassing these 2 components would be appreciated.
The circuit is being powered by a 3.7v 150mAh lithium ion rechargeable battery. So I need to save as much power as I can with this small battery to get some life. Also, I don’t believe anything within my circuit requires more than the 3.4-4.2volts this battery should provide (I only have a hall sensor and tactile button hooked up to the MicroView). I’m not uising the 5V pin, so stepping the voltage up isn’t necessary, but is drawing a bunch of power in power-down mode.
