Adafruit Feather 32u4 FONA User manual
Adafruit Feather 32u4 FONA
Created by lady ada
Last updated on 2016-04-27 02:03:47 PM EDT
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Guide Contents
Guide Contents
Overview
Pinouts
Power Pins
Logic pins
Cellular Module
Other Pins!
FONA connections & LEDs
Assembly
Header Options!
Soldering in Plain Headers
Prepare the header strip:
Add the breakout board:
And Solder!
Soldering on Female Header
Tape In Place
Flip & Tack Solder
And Solder!
Power Management
Battery + USB Power
Power supplies
Measuring Battery
ENable pin
Cellular Power Usage
Turning on the FONA Feather
Sending an SMS
Enabling GPRS
TCPIP connection
Sending an MQTT packet (about 200 bytes)
Disabling GPRS
Arduino IDE Setup
Using with Arduino IDE
Install Drivers (Windows Only)
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 2 of 59
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Blink
Manually bootloading
Ubuntu & Linux Issue Fix
FONA Test
Download Adafruit_FONA
Wire up and Power!
Load Demo
Using the Test Sketch
Hardware Test
Battery voltage
Check SIM CCID
Network Test
Check RSSI (network signal strength)
Checking Network Registration
Audio Settings & Test
Set and Get audio volume
Setting Headset or External audio
Playing Toolkit Tones
Phone Calls
Make Phone Calls
SMS
Send and Read SMS
FM Radio (FONA800)
FM Radio (FONA 800 only)
Feather FONA FAQ
HELP!
Downloads
Schematic
Fabrication Print
Datasheets:
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 3 of 59
Overview
Feather is the new development board from Adafruit, and like its namesake it is thin, light, and lets you
fly! We designed Feather to be a new standard for portable microcontroller cores.
This is the Adafruit Feather 32u4 FONA - our take on an 'all-in-one' Arduino-compatible +
audio/sms/data capable cellular with built in USB and battery charging. Its an Adafruit Feather 32u4
with a FONA800 module (http://adafru.it/1946), ready to rock! We have other boards and accessories
in the Feather family, check'em out here (http://adafru.it/l7B).
At the Feather 32u4's heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic, a chip setup we've
had tons of experience with as it's the same as the Flora (http://adafru.it/dVl). This chip has 32K of
flash and 2K of RAM, with built in USB so not only does it have a USB-to-Serial program & debug
capability built in with no need for an FTDI-like chip, it can also act like a mouse, keyboard, USB MIDI
device, etc.
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 4 of 59
Since you'll be taking this on the road, we added a connector for any of our 3.7V Lithium polymer
batteries and built in battery charging. A 500mAh+ Lipoly battery is required for use, it keeps the
cellular module happy during the high current spikes. Plug the Feather into microUSB to charge at
500mA.
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 5 of 59
Here's some handy specs! Like all Feather 32u4's you get:
Measures 2.4" x 0.9" x 0.28" (51mm x 23mm x 8mm) without headers soldered in
Light as a (large?) feather - 8.2 grams
ATmega32u4 @ 8MHz with 3.3V logic/power
3.3V regulator with 500mA peak current output
USB native support, comes with USB bootloader and serial port debugging
You also get tons of pins - 20 GPIO pins
Hardware Serial, hardware I2C, hardware SPI support
8 x PWM pins
10 x analog inputs
Built in 500mA lipoly charger with charging status indicator LED
Pin #13 red LED for general purpose blinking
Power/enable pin for the 3.3V regulator
4 mounting holes
Reset button
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 6 of 59
Connect your Feather to the Internet or make phone calls with our trusted-and-tested FONA module.
At the heart is a GSM cellular module (we use the latest SIM800) the size of a postage stamp. This
module can do just about everything.
Quad-band 850/900/1800/1900MHz - connect onto any global GSM network with any 2G SIM
(in the USA, T-Mobile is suggested)
Make and receive voice calls using an external 8W speaker + electret microphone
Send and receive SMS messages
Send and receive GPRS data (TCP/IP, HTTP, etc.)
Scan and receive FM radio broadcasts (yeah, we don't exactly know why this was included but it
works really well)
AT command interface with "auto baud" detection
Pair-able Bluetooth client interface with SPP (for controlling the module) as well as audio.
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 7 of 59
You will also need some required accessories to make Feather FONA work. These are not
included!
SIM Card! A 2G Mini SIM card is required to do anything on the cellular network. US AT&T no
longer sells 2G SIMs and will shut off their 2G network, so for American customers we
recommend any T-Mobile or reseller (TING, SIMPLE mobile, etc) that uses the T-Mobile
network. (http://adafru.it/2505)
Lipoly Battery - 500mAh or larger! This 500mAh (http://adafru.it/drL)battery, or this
1200mAh (http://adafru.it/258) will work great.
MicroUSB cable (http://adafru.it/592) for charging the battery.
External Antenna - We like this slim sticker-type (http://adafru.it/1991), which plugs right in.
Alternatively, this straight SMA one (http://adafru.it/1859) or this right-angle SMA one will
work (http://adafru.it/1858) but you'll also need a uFL to SMA adapter cable (http://adafru.it/851)
so you can connect to your SMA antenna
External Mic & Speaker - If you want to make phone calls, you'll also need this electret
mic (http://adafru.it/dDa) and mini 8 ohm speaker (http://adafru.it/dDb)
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 8 of 59
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 9 of 59
Pinouts
The Feather 32u4 FONA is chock-full of microcontroller goodness. There's also a lot of pins and ports.
We'll take you a tour of them now!
Power Pins
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 10 of 59
GND - this is the common ground for all power and logic
BAT - this is the positive voltage to/from the JST jack for the optional Lipoly battery
USB - this is the positive voltage to/from the micro USB jack if connected
EN - this is the 3.3V regulator's enable pin. It's pulled up, so connect to ground to disable the
3.3V regulator. Note that the cellular module is powed by VBAT so this will only disable the
microcontroller
3V - this is the output from the 3.3V regulator, it can supply 500mA peak
Logic pins
This is the general purpose I/O pin set for the microcontroller. All logic is 3.3V
#0 / RX - GPIO #0, also receive (input) pin for Serial1 and Interrupt #2
#1 / TX - GPIO #1, also transmit (output) pin for Serial1 and Interrupt #3
#2 / SDA - GPIO #2, also the I2C (Wire) data pin. There's no pull up on this pin by default so
when using with I2C, you may need a 2.2K-10K pullup. Also Interrupt #1
#3 / SCL - GPIO #3, also the I2C (Wire) clock pin. There's no pull up on this pin by default so
when using with I2C, you may need a 2.2K-10K pullup. Can also do PWM output and act as
Interrupt #0.
#5 - GPIO #5, can also do PWM output. Also connected to the FONA's DTR pin if you want to
use it for powersaving functionality, which is not enabled by default
#6 - GPIO #6, can also do PWM output and analog input A7. Also connected to FONA RTS in
case you want to use flow control, which is not enabled by default
#9 - GPIO #9, connected to FONA RXD.
#10 - GPIO #10, also analog input A10 and can do PWM output.
#11 - GPIO #11, can do PWM output.
#12 - GPIO #12, also analog input A11 and can do PWM output.
#13 - GPIO #13, can do PWM output and is connected to the red LED next to the USB jack
A0 thru A5 - These are each analog input as well as digital I/O pins.
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 11 of 59
SCK/MOSI/MISO - These are the hardware SPI pins. Also used to reprogram the chip with an
AVR programmer if you need.
Cellular Module
Now to the fun part, the cellular module. THere's a few pins that are used to control the module. It
uses SoftwareSerial to communicate with the microcoller
#8 - used as the FONA TXD (data out from module to AVR)
#9 - used as the FONA RXD (data out from AVR to module)
#7 - used as the FONA RI (ring interrupt) pin, you can use this to alert you when an SMS or
phone call comes in
#4 - used as the FONA Reset pin. You can pulse this pin low to reset the FONA, handy when
starting up
Optional pins:
#5 - This pin is available on the breakout and is also connected to the FONA's DTR pin if you
want to use it for powersaving functionality, which is not enabled by default
#6 - This pin is available on the breakout and is connected to FONA RTS in case you want to
use flow control, which is not enabled by default
Other Pins!
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 12 of 59
RST - this is the Reset pin, tie to ground to manually reset the AVR, as well as launch the
bootloader manually
ARef - the analog reference pin. Normally the reference voltage is the same as the chip logic
voltage (3.3V) but if you need an alternative analog reference, connect it to this pin and select
the external AREF in your firmware. Can't go higher than 3.3V!
Key - this is by default tied to ground, cut the trace on the bottom and wire to a microcontroller
pin to manually turn the module on and off. (Pulse low for a few seconds to change from on to
off) This is the only way to truly disable the cellular module.
Mic+ and Mic- connections for attaching an electret microphone for audio applications (external
audio interface)
Spk+ and Spk- connections for attaching a 8 ohm 1W speaker for audio applications (external
audio interface)
FONA connections & LEDs
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 13 of 59
All the way to the right we have the cellular-only connection parts. Up top is a standard uFL connector,
you attach your GSM antenna here
Below that is the bluetooth antenna (small white rectangle with red marking)
At the bottom are the two cell-status LEDs.
The middle PWR LED will light up green whenever the cellular module is active and has good power.
The NET LED will blink in blue let you know the status of the cellular connection You can use this for
checking the current state without sending an AT command:
64ms on, 800ms off - the module is running but hasn't made connection to the cellular network
yet
64ms on, 3 seconds off - the module has made contact with the cellular network and can
send/receive voice and SMS
64ms on, 300ms off - the GPRS data connection you requested is active
By watching the blinks you can get a visual feedback on whats going on
On the bottom is a microSIM push-push holder. Slot your microSIM in here and press in until it clicks
There's also a spot you can solder an antenna if you want to use the FM receiver capability.
Above that is nicely labeled Mic/Speaker pads
At the very bottom is the jumper for the KEY pad - cut this to let you control the module's on/off key
manually. By default KEY is tied to ground so the module is always powered and on.
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 14 of 59
Assembly
We ship Feathers fully tested but without headers attached - this gives you the most flexibility on
choosing how to use and configure your Feather
Header Options!
Before you go gung-ho on soldering, there's a few options to consider!
The first option is soldering in plain male headers, this lets you plug in the
Feather into a solderless breadboard
Another option is to go with socket female headers. This won't let you plug
the Feather into a breadboard but it will let you attach featherwings very
easily
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 15 of 59
We also have 'slim' versions of the female headers, that are a little shorter
and give a more compact shape
Finally, there's the "Stacking Header" option. This one is sort of the best-of-
both-worlds. You get the ability to plug into a solderless breadboard and
plug a featherwing on top. But its a little bulky
Soldering in Plain Headers
Prepare the header strip:
Cut the strip to length if necessary. It will be easier to solder if
you insert it into a breadboard - long pins down
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 16 of 59
Add the breakout board:
Place the breakout board over the pins so that the short pins
poke through the breakout pads
And Solder!
Be sure to solder all pins for reliable electrical contact.
(For tips on soldering, be sure to check out our Guide to
Excellent Soldering (http://adafru.it/aTk)).
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 17 of 59
Soldering on Female Header
Tape In Place
For sockets you'll want to tape them in place so when you flip
over the board they don't fall out
Flip & Tack Solder
After flipping over, solder one or two points on each strip, to
'tack' the header in place
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-32u4-fona Page 19 of 59
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