- Jun 14, 2013
- Jun 14, 2013
GSM modem idle current 25 mA? That's a reasonable figure.
Yes, a 2000 mAh battery should give about 70 hours at that current.
Have you confirmed that the GSM modem will work properly at 3.7V? The specification is very clear that its input range is 4.5~5.5V. If you need to add a boost converter, expect an increase of about 50% in the current, and a reduction in operating time down to about 50 hours.
Yeah, the gsm has been working great for the last few days and it idled over night and in to the next day even when i didnt have the mosfet cutting off the booster.
I measured all of the current loads for each part:
26 ma, idle
60 ma, incoming call (RI)
90 ma, connected to a call
Idle 58ma (not ringing bell)
Everything is working now so I am back on the USART to capture the RING and NO CARRIER strings instead of soldering that wire to the RI pin on the GSM.
Reading up on how to do interrupts now... I think that is the best way to monitor the USART for character streams so in can all happen outside of my main loop.
I figured I'd create a global array and have an interrupt watch RCIF and store incoming characters into the global array. Then my main loop can look at that array for "RING" and "NO CARRIER".
On a side note, I am a little concerned now that the GSM module will be obsolete soon and not supported by cell providers becuase it is not 3G.. That's a whole other issue to deal with though.. Not going to worry about it right now but I got a little hassle with ATT today when trying to get another line added to my plan. One guy said he can't do it after I gave him the IMEI number because it wasn't 3G.. Then I called back and another guy hooked me right up no questions so I don't know what that's all about. Maybe he was just trying to talk me into buying a new phone..
Let me know if you ever run across one of these! http://www.britishtelephones.com/atm/l11576.htm