MattairTech MT-DB-U4 User manual

MT-DB-U4 User Guide
December 30, 2015 1 http://www.mattairtech.com/

MT-DB-U4 User G ide
Table of Contents
Table of Contents
Overview........................................................................................................................4
Introduction.......................................................................................................................................4
MT-DB-U4 Features..........................................................................................................................4
ATmega32U4 Features.....................................................................................................................5
MT-DB-U4 Hardware.....................................................................................................8
Board Revisions................................................................................................................................8
Pin Descriptions................................................................................................................................9
Boot Jumper / RESET button / LED................................................................................................10
ISP Header.....................................................................................................................................10
JTAG...............................................................................................................................................11
Mounting Holes...............................................................................................................................11
Power Configuration..................................................................................................12
Bus Powered - 5V...........................................................................................................................12
Externally Powered – 3.4V to 5.5V..................................................................................................12
Externally Powered – 3.0V to 3.6V..................................................................................................12
USB Shield......................................................................................................................................12
Arduino Compatibility (IDE 1.6.7)..............................................................................13
What's New.....................................................................................................................................13
Summary.........................................................................................................................................13
Special Notes..................................................................................................................................14
Pin Configurations...........................................................................................................................14
MT-DB-U6 (AT90USB64/AT90USB128).........................................................................................15
MT-DB-U4 (ATmega32U4)..............................................................................................................16
MT-DB-U1/MT-DB-U2 (AT90USB162/ATmega32U2).....................................................................16
Pin Capabilities...............................................................................................................................17
Using Arduino with MattairTech USB boards..................................................................................18
Serial Monitor..................................................................................................................................18
Updated Tone.cpp...........................................................................................................................18
Detailed Memory Usage Output After Compilation..........................................................................19
USB Technical Notes......................................................................................................................19
Installation.......................................................................................................................................20
Driver Installation............................................................................................................................20
Windows.........................................................................................................................................20
Linux...............................................................................................................................................21
OS X...............................................................................................................................................21
AVR Core Installation......................................................................................................................21
Uploading the First Sketch..............................................................................................................22
USB CDC Bootloader (Arduino compatible)....................................................................................22
Bootloader Firmware Installation Using the Arduino IDE.................................................................22
Using AVRDUDE Standalone.........................................................................................................23
December 30, 2015 2 http://www.mattairtech.com/

MT-DB-U4 User G ide
Possible Future Additions................................................................................................................23
ChangeLog.....................................................................................................................................23
License and credits.........................................................................................................................24
CDC Bootloader (Arduino/AVRDUDE)......................................................................25
CDC Serial Driver............................................................................................................................25
CDC Bootloader..............................................................................................................................25
DFU Bootloader (FLIP/dfu-programmer)..................................................................28
FLIP................................................................................................................................................29
dfu-programmer..............................................................................................................................31
Running Bitlash Demo...............................................................................................32
Schematic....................................................................................................................34
Fuse and Lock Settings.............................................................................................35
Troubleshooting / FAQ...............................................................................................35
Support Information...................................................................................................35
Legal.............................................................................................................................36
Appendix A: Precautions...........................................................................................37
Appendix B: Other MattairTech Products................................................................38
December 30, 2015 3 http://www.mattairtech.com/

MT-DB-U4 User G ide
Overview
Overview
Introduction
The MT-DB-U4 is a development board for the Atmel ATmega32U4 USB microcontroller. The
board has 40 pins in a dual inline configuration with 100 mil pin spacing and 700 mil row spacing
which allows for easy mounting on a breadboard. It includes a mini USB connector, status LED,
16MHz crystal, reset button, HWB boot jumper, and ISP header pads. A bootloader comes
preinstalled which allows programming of the chip over USB without an external programmer. An ISP
header is available which can be used with an external programmer. This header can be reconfigured
to allow the MT-DB-U4 itself to be used as an ISP programmer (hex file available on website), or to be
used as a SPI master or slave. The board can be powered via USB at 5V or it can be externally
powered (3V - 5.5V). All pins are routed to headers, including those used by on-board hardware. The
chip can be clocked externally, and the board is compatible with HV programming. The USB
connections are also routed to header pins, which allows for panel-mount USB connectors. The PCB
is high-quality with ENIG (gold-plated) finish, red soldermask, and white screenprinting showing the
pinout and Arduino pin numbering. There are two 3mm mounting holes (~5mm pad). It measures
approximately 2.1” x 0.9” (52mm x 23mm) and is 0.062” (1.6mm) thick.
MT-DB-U4 Features
●ATmega32U4 USB microcontroller
●32KB FLASH, 2.5KB SRAM, 1KB EEPROM
●12 10-bit ADC channels (1 used by LED which can be disconnected)
●Serial USART, SPI, and TWI (I2C) communications
●4 timers with 14 PWM channels (up to 7 simultaneous)
●Arduino compatible (now supports IDE 1.6.7 and boards manager)
●CDC (Arduino/AVRDUDE) or DFU (FLIP) bootloader preinstalled
●Bitlash preinstalled (Arduino command shell)
●ISP header (program chip using external programmer)
●16MHz crystal
●Green Status LED
●Reset button
●Bootloader jumper
●Mini USB connector
●Powered by USB or external power supply
●5V (USB) or 3V - 5.5V (external)
●All pins routed to headers (including those used by on-board hardware)
●Can be mounted on a breadboard
●USB pins routed to header pins (for panel-mount USB connector)
●Inductor on analog supply with separate ground pin
●High-quality PCB with gold-plated finish
●Two 3mm mounting holes (~5mm pad)
●Measures approx. 2.1” x 0.9” (52mm x 23mm) and 0.062” (1.6mm) thick.
December 30, 2015 4 http://www.mattairtech.com/

MT-DB-U4 User G ide
ATmega32U4 Features
●
● !
"#$%!&!&"& ' ()*!
"$+*,!-&.'&&
"/!(0-
"1-#23!-!#24
"0 -+(!-
●56&
"$+7(&(&8/&
"+9%7(&
"#7(&))0
".:)& (&;#<<<</&:#<<<<<))0
"6;+<(&%= :#<<(&+%=
"0- -'&
(&8(0-
3!..0-
&!---&--!18
"'!(
●>3,?)))&9##@A9#-B
"!(& -8&>3,
")*&0-68!!--
"/&))0/!&&'&!>3,
●1+9</!&-:-6!!-3& -
" -&!(1&!&-C+9<
"!--&&&!-#+8:&#9%8:&
")-< 3&&;!-2@8(&
"28)-&50!6&!'!-
&!&3&&
" C!8)-&&4!-+%28(&!88'
"/!(-$+8(&16-(
"!&-:&!!-&
" 1&-&&81!&&
"@4/!&-!&0-
"1!& :6&D!&
" (&&&--
●-/!&
"0-1-3;$+!-A24-
"083: !-& -
"3#283: !-& - -!
"0#<8-3: !?2@4B -
"/!8. &
"/!. &8&!+#2&
"*. &-0-8&!
+##&
"0!-! -!
"#+&#<86 ?!&6E &8,B
"813/ 
"&:
"(0+
"8.3-0-0&
"0- -
"!-.'!- 
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December 30, 2015 5 http://www.mattairtech.com/

MT-DB-U4 User G ide
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December 30, 2015 6 http://www.mattairtech.com/

MT-DB-U4 User G ide
December 30, 2015 7 http://www.mattairtech.com/

MT-DB-U4 User G ide
MT-DB-U4 Hardware
MT-DB-U4 Hardware
Board Revisions
There are two board revisions, A and B. Boards shipped after November 22, 2 12
are revision B. Revision B adds two 3mm (~5mm pad) mounting holes, adds a solder
jumper to allow disconnection of the LED from pin D7, adds solder jumpers to allow
connection of the xtal traces to two main header pins, adds Arduino pin numbering to the
screen printing, and makes other various changes to improve the manufacturing process.
Revision A Revision B (current)
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MT-DB-U4 User G ide
Pin Descriptions
Pin Description
Gnd Digital ground
5V, Vbus 5V output from USB Vbus. Vbus pin is tied to 5V pin. These pins are
connected to the Vbus and UVcc pins of the microcontroller.
Vcc Voltage input pin. Use solder jumper J1 to connect this pin to 5V (default
setting) when using USB power. In this case, Vcc is an output. Leave J1
unconnected to supply power from an external source to the Vcc pin. This
pin is connected to the Vcc and AVcc pins on the microcontroller, as well
as the ISP header and reset pullup. See Power Configuration Section.
3.3V 3.3V output from the microcontrollers internal 3.3V regulator. This pin is
connected to Ucap on the microcontroller.
Avcc Voltage input to the analog section of the microcontroller. This pin is
connected to Vcc through a 10uH inductor and 100nF capacitor and
provides power to the microcontroller analog section (Avcc pin).
Aref Voltage input. This is the reference voltage used by the ADC in the
microcontroller. DO NOT connect if using an internal reference.
Agnd Analog ground
RST Connects to reset pin of microcontroller as well as the reset button. A 10K
pullup resistor and 100nF capacitor are connected to this pin.
E2 / B (Boot) This pin is connected to the HWB jumper. The jumper is connected to
ground through a 240 ohm resistor. The pin is sampled after all reset
sources, including power-up. If the pin is low (HWB jumper installed), then
the bootloader is run. If the pin is high (HWB jumper removed), then the
user application is run. This pin functions as a normal GPIO pin at all other
times. The 240 ohm resistor provides short-circuit protection in case the
pin is used as an output and the jumper is installed.
D7 / L (LED) The green status LED is connected to this pin. The LED is connected to
ground through a 240 ohm resistor. Drive the pin high to turn on the LED.
It can be disconnected by cutting the solder jumper trace (Rev B only).
xtal1 This pin is connected to the on-board 16MHz crystal. If using an external
clock, connect it to this pin, connect the solder jumper (Rev B only), and
configure the microcontroller fuses to use an external clock. This is also
useful for HV programming or recovery from incorrectly set fuses.
xtal2 This pin is connected to the on-board 16MHz crystal. This pin is useful
along with xtal1 to connect an external crystal. Board revision B has a
solder jumper to connect this to the external header pin.
E6, F0, F1, F4, F5, F6,
F7
These are generally used as analog pins. Analog ground plane runs under
these pins. Consult datasheet for functionality.
All other pins Consult datasheet for functionality.
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MT-DB-U4 User G ide
Boot Jumper / RESET button / LED
This section does not apply to the Atmel DFU bootloader option, in which case, the fuses will be left
at their factory default settings and the factory installed Atmel DFU bootloader will not be overwritten.
The boot jumper (labeled HWB) selects between the bootloader and user application. The pin is
sampled after reset or power-up. Note that the hardware HWB function of the ATmega32U4 is disabled
(HWBE fuse is disabled) and the bootloader startup code is always run after reset or power-up (BOOTRST
fuse is set). This startup code then samples the state of the HWB pin. If it is high, the user application runs.
Otherwise, the bootloader continues to run, waiting for programming instructions while pulsing the LED.
The LED remains on when jumping to the user application. The bootloader always runs at 8 MHz, which is
compatible with lower voltages. It remains at 8MHz when jumping to the user application. The user may
then set the cpu speed to 16MHz in software, if running at 5V.
It is not necessary to remove and replace the jumper when switching between the bootloader and
the user application. The jumper can be left on. After FLASH programming, the CDC bootloader will
automatically jump to the application. If using the DFU bootloader, then you can command FLIP or dfu-
programmer to jump to the application. Then, when running the application, the reset button can be
pressed to re-enter the bootloader. This is useful when writing and debugging firmware. When the firmware
is complete, the jumper can be removed so that future resets will always run the application.
ISP Header
The ISP header is configured by default to allow ISP programming using an external programmer.
That is, RESET is routed to pin 5. Pin 1 is marked on the board (it is the pin closest to the chip). The ISP
header can be reconfigured so that pin PB0 (SS) is connected to pin 5 rather than RESET. This can be
done by switching solder jumper J2, next to the ISP header, to the position opposite to the “ISP” label. This
allows the MT-DB-U4 to be used as an AVRISPmkII programmer itself, using Dean Camera's AVRISPmkII
software available at http://www.fourwalledcubicle.com/. A precompiled hex file will be made available at
http://www.mattairtech.com/ on the MT-DB-U2 product page. Note that when using the ISP header in this
way, Vcc and ground are output to the target board. Therefore, the target board should not be powered
itself. You should also verify that it is safe to power the target board through the ISP connector. Another
use for the ISP header configured with SS on pin 5 is to make use of SPI, either as a master or slave. SPI
can also be used on the normal DIL headers.
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