Cannot init Blynk + Adafruit Fona 808 on Mega 2560

Solved
1

I have an Arduino Mega 2560 and a Adafruit Fona 808 shield.
In the hardware list I saw this combination should work, but I can’t get it working yet.
When I use the Adafruit test the serial monitor says “FONA is OK” and “Found FONA 808 (v2)” and I can run the test cases like read the sim ID, etc.
So I assume the wiring, available power etc all is OK.
Even though I am using the Mega I am using SoftwareSerial since Adafruit Fona currently does not support hardware serial.

However, when I use the SIM800_SIM900 example code and populate my RX and TX pins it unfortunately does not work.
The serial monitor says

Initializing modem…
[13216]
___ __ __
/ _ )/ /_ _____ / /__
/ _ / / // / _ / '/
///_, /////_
/__/ v0.4.6 on Arduino Mega

[13223] Modem init…
[23439] Cannot init

I have already tried the AT_debug but all baud rates fail and I receive:

Module does not respond!
Check your Serial wiring
Check the module is correctly powered and turned on

Hope someone can help me out from here. Or has perhaps a working example for the Fona 808.
Thanks

2

We have some users reported it works OK, however I don’t have such hardware to test with.

3

What could be a next step for me to get this up and running?
I have tried connecting the Adafruit Fona to all Rx/TX pins on the Mega but neither worked. The AT debug fails on all baud rates.

4

@oudevolvo I suggest you ask over at the Adafruit forums as this is their product. Once you have it communicating with the Arduino properly, then we can better assist with Blynk.

https://forums.adafruit.com/

5

Thanks, done that.
However, the thing is I got the Fona 808 working with my Mega using the FONAtest sketch and the Adafruit library. It says:

FONA test basic
Initializing… (may take 3 sec)
Attempting to open comm with ATs

Then a couple of
—> AT
<—
Etc
And in the end

SIM 808 R14.18
OK
FONA is OK
Found FONA 808 (v2)

And then shows the IMEI.
Battery charge is 100% and using that test sketch I can request a URL (and get a response), read SMS messages from SIM.
But let’s see what comes from the Adafruit forums.
Will keep you posted.

6

To update this topic as well, I’ve got it working thanks to the support via/on Github. For the full story see https://github.com/vshymanskyy/TinyGSM/issues/18
In short:

  • I had to change the order of the RX and TX wiring
  • Fona gave an error on command AT&FZE0. Changed it in TinyGsmClientSIM800.h so it outputs AT&F0 instead and now it works
1 Like
7

Hello, I’m having the same problem with an arduino UNO and a fona808. I tryed to modify the TinyGsmClientSIM800.h file and I switched RX and TX. Do you have any other suggestion?

Thank you for your help!

8

Are you able to connect to the module using another library or even direcltly via a TTL cable?

9

I’ve solved the issue, it was just a matter of copying the right files to the right place.

Thank you for the help

1 Like
10

A post was split to a new topic: Modem init problem with SIM800L