The microUSB (on the shield, in CHARGE mode and powered via USB or DC power) is only used to charge the battery. Without a battery installed it will flicker on and off so it cannot be used to power a FONA minus battery.
A 1200mAh+ sized Lithium ion/polymer battery is required, nothing else will be able to easily power the FONA and provide the correct voltage range even during 2 Amp spikes.
We keep getting people who ask "Hey I know its a requirement but I want to build a buck/boost/linear 3.8V regulator and it wil be OK because I said so" and then they realize it doesn't work well
The FONA design depends on a Lipoly battery. The battery is not optional. The battery is essential to function. If you do not want a Lipoly battery you will have to use a different cellular module design. All of our FONAs require, depend and will not work without a Lipoly battery
You can keep the battery topped up with an external 5V power supply for long term usage but the battery is still required even if plugged into USB
You can always factory reset the FONA by sending it the
command. Say with fona.println("ATZ") or using a USB console cable to send commands. If you set an odd fixed baud rate (e.g. you cannot even get an OK when you send AT), a USB serial console cable will be helpful it quickly changing baud rates in your terminal software to get back to a working AT/OK setup!
Note that you do have to use a compatible headset. Not all CTIA headsets will work, the ones we have in the shop are known to work and so do many other Android but iPhone headsets do not.
You can also use 'external' audio on the FONA (electret mic and speaker soldered to FONA) but you cannot mix and match. Either you use headset or you use external audio. You cant use external mic and headset speaker.
Right now we only know that the FONA library and shields work with Arduino UNO. Any other platforms may require porting work
Yes! You can use the Lipoly as sort of a 'backup battery' - keep charging it via MicroUSB (on the shield, in CHARGE mode and powered via USB or DC power) during use. If the MicroUSB loses power, the FONA will keep going.
We've noticed a lot of problems that are 'weird' that are a results of using batteries with the wrong polarity.
All batteries from adafruit have the right wire colors/polarity for the FONA
Batteries not from Adafruit are not guaranteed to have the right pinout! Using the wrong pinout may damage the FONA and/or make it act 'odd'!
That will work fine, as long as the SIM can register to the 2G network at all, it is acceptable to use
The AT&T GSM network is going to be live until January 2017. If you're reading this and it's 2017, you're outta luck. If not, you can try to get an AT&T SIM activated to the 2G GSM network but its not going to do that by default. You'll have to call up or talk to an AT&T rep and it may not go so well because they really don't want people to use their GSM network.
You can also call up T-Mobile and say you can't get connected consistently - they may send you a free signal booster
A 1200mAh battery can run the FONA on 'standby' for a day or two.
The FONA 808 has two versions, due to a revision of the module itself. Version 1 has two barcodes on the front and is part #S2-10606-Z1F01. Version 2 has a QR code on the front and is part #S2-10606-Z1F02. V2 has a newer/better chipset (MT3337 instead of MT3336) but the commandset has changed. Which is annoying but adaptable!
If you are using V1, use this GPS command document for how to interact with the GPS subsystem
If you are using V2, use this GNSS command document instead.
We're not sure exactly why you need to tell the FONA3G to look on the SIM specifically, but its easy to set up. In Adafruit_FONA.h uncomment
//#define FONA_PREF_SMS_STORAGE "SM"
//#define FONA_PREF_SMS_STORAGE "SM"
Then recompile and upload
I'm trying to reset the FONA with my microcontroller/computer and pulling the RESET pin low via a GPIO isnt working?
There's a superfluous level shifting diode that we put on the FONA and FONA 808 breakouts - it turns out it isn't necessary and for microcontrollers with weaker outputs it can keep the FONA from resetting.
You can 'bridge' this diode with a piece of wire, its perfectly safe and may give you a little more headroom. There's already level shifting inside the modules so there's no risk to this mod.
Simply solder a small wire between the two pads, or remove the diode and replace with a 0 ohm resistor or wire.