how to make the PIC18 Consumption low as possible ??

[mot1639]

Hi All ,

One question for electronic expertise,

I have PIC18f25k22 , which is a great microcontroller, I made small project which is connect to GSM modem and temperature sensor , the project will send me SMS every 20 Minutes, the pic18 will read temperature them send sms using gsm modem , then after that the pic18 will be switch off the modem , the current consumption when PIC18 + modem work is between 30~120mA. when i switch off the modem it go low as 5~10 mA. the pic18 will stop delay for 20m and then again switch on the modem and work same , my question is how i can reduce the current consumption when the pic is in delay . I use internal 16 MHz . NO LED used .

please help me out in this issue, can i go to low as 1 MA or less .

regards

 

[CocaCola]

What do you mean 'in delay' ? If you mean a software loop that is not what you want... You would put the chip into sleep and have it wake up every few seconds via the watch dog and then go back to sleep until the 20 minutes have elapsed (you would count the number of wake ups until you get to 20 minutes)

This is not as high of energy savings as putting it into deep sleep and depending upon an external source to wake it up but it will drop current consumption drastically vs leaving it up and running normally in some software delay loop... Also make sure you toggle all the I/O pins appropriately before putting it to sleep so that it's not sinking or sourcing power it doesn't need to while sleeping...