Fona 808 - Can't get to boot - Flashing blue LED.

[TimGUK]

Hi,

I have a FONA 808 that arrived today. I have connected it as follows:

5V - Powered from 5V rail
GND - Connected to 0V rail
Vio - Powered from 5V rail
Key - Connected to 0V rail
vBat - Connected to 3.9V via voltage divider

I have no battery connected as I plan to run this from my standard power source.

When I connect everything I get a solid orange LED and blinking blue , red and green LEDS (about 3 second gaps - they don't all blink together though). Connected or disconnecting the vBat line makes no difference at all. The LEDs flash if it is connected or not and applying the line causes no changes at all.

Should the blue LED be solid when it is powered?

I don't believe I have done anything wrong. I have been very careful with my connections and have checked them time and time again.

Is the unit faulty perhaps?

[TimGUK]

A bit more info on this.

If I disconnect the key line the unit does something slightly different. When I turn it on the orange and green LEDs are solid. When I hold the key button the green LED goes off, it waits a few seconds, the blue LED flashes and then it goes back to the solid orange and green. This can be repeated over and over.

It is though it is trying to boot - flashing the blue LED and then turning back off again. Obviously the reason it constantly flashes when the key line is connected is that it is doing this over and over again automatically.

[TimGUK]

Hi,

A bit more info - I managed to find a 3.7 Lipo on another project and when connected the unit boots and the blue light goes solid. As soon as the Lipo is disconnected it goes back to rebooting.

The FAQ clearly states the unit can be powered from a 3.4V - 4.4V supply direct to the VBat port:

https://learn.adafruit.com/adafruit-fon ... akout/faqs

Am I correct in thinking the VBat pin is the second pin on the breakout - The one between 5V and GND (marked Bat)?

Any support welcomed.

[reso_nate]

I'm seeing the same behavior: when I hold key for a couple seconds the power and net LEDs both light up for about a second and then turn off. If I tie the KEY pin to ground this happens repeatedly.

I've tried two different fona 808, with two different batteries and 2 different SIM card. I've tried with a USB console cable to my computer and also tried with it wired directly to a pi3. If I send an AT command during that brief moment it is on -- by mashing keys -- I can sometimes get it to give the below response:

RDY

+CFUN: 1


Which is why I think it is trying to boot and then encountering some situation that makes it shutdown like over-voltage/under-voltage or maybe failure to find the SIM or network?

[adafruit_support_mike]

Post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.