MattairTech MT-DB-U2 User manual

MT-DB-U2 Manual
October 29, 2015 1 http://www.mattairtech.com/

MT-DB-U2 Manual
Table of Contents
Overview........................................................................................................................3
Introduction.......................................................................................................................................3
MT-DB-U2 Features..........................................................................................................................3
ATmega32U2 Features.....................................................................................................................4
MT-DB-U2 Hardware.....................................................................................................6
Layout / Header Pins.........................................................................................................................6
Solder Jumpers.................................................................................................................................7
Pin Descriptions................................................................................................................................8
PWM Filters......................................................................................................................................9
Clock Source.....................................................................................................................................9
HWB Jumper / RESET button / LED.................................................................................................9
ISP Header.....................................................................................................................................10
Power Configuration..................................................................................................11
USB Bus Powered -- 5V..................................................................................................................11
USB Bus Powered – 3.3V...............................................................................................................11
Externally Powered – 4.0V to 5.5V..................................................................................................12
Externally Powered – 3.0V to 3.6V..................................................................................................12
USB Shield......................................................................................................................................12
Arduino Compatibility................................................................................................13
Features..........................................................................................................................................13
Pin Mapping....................................................................................................................................13
Installation.......................................................................................................................................14
Using Arduino..................................................................................................................................14
Using Libraries................................................................................................................................15
USB Serial interface........................................................................................................................15
CDC Bootloader (Arduino/AVRDUDE)......................................................................18
CDC Serial Driver............................................................................................................................18
CDC Bootloader..............................................................................................................................18
DFU Bootloader (FLIP/dfu-programmer)..................................................................20
FLIP................................................................................................................................................21
dfu-programmer..............................................................................................................................23
Running Bitlash Demo...............................................................................................24
Schematic....................................................................................................................26
Troubleshooting / FAQ...............................................................................................27
Support Information...................................................................................................27
Acknowledgments......................................................................................................27
Legal.............................................................................................................................28
Appendix A: Precautions...........................................................................................29
Appendix B: Other MattairTech Products................................................................30
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MT-DB-U2 Manual
Overview
Overview
Introduction
The MT-DB-U2 is a development board for the Atmel ATmega32U2 USB microcontroller. The
Atmega32U2 contains 32 KB of flash, 1 KB of RAM, 1 KB EEPROM, 22 programmable IO pins, and a
USB device controller. The board has 32 pins in a dual inline configuration with 100 mil pin spacing
and 600 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, 3 PWM filters, and ISP header
pads. A bootloader comes preinstalled which allows programming of the chip over USB without an
external programmer. The ISP header can be used with an external programmer for in-system
programming. This header can be reconfigured to allow the MT-DB-U2 itself to be an ISP
programmer, or to be used as a SPI master or slave. The board can be powered at 5V via USB, at
3.3V via the ATmega32U2 internal regulator and USB, or it can be powered externally (3V – 3.6V or
4.0V – 5.5V). All programmable IO 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. It measures approximately 1.7” x 0.8” (42mm x 20mm) and is 0.062” (1.6mm) thick.
MT-DB-U2 Features
●ATmega32U2 USB microcontroller
●32KB FLASH, 1KB SRAM, 1KB EEPROM
●USB device controller, Serial USART, and SPI communications
●2 timers with 5 PWM channels
●Arduino compatible
●CDC (Arduino/AVRDUDE) or DFU (FLIP) bootloader preinstalled
●Bitlash preinstalled (Arduino command shell)
●ISP header pads (program chip using external programmer)
●16MHz crystal
●Green Status LED
●3 RC PWM filters on each output compare pin of 16-bit timer 1 (can be disconnected)
●Reset button
●Bootloader selection jumper
●Mini USB connector
●Can be powered via USB at 5V (Vbus) or 3.3V (ATmega32U2 internal regulator)
●Can be powered externally at 3V to 3.6V or 4V to 5.5V
●All programmable IO pins routed to headers (including those used by on-board hardware)
●USB pins routed to header pins (for panel-mount USB connector)
●High-quality PCB with gold-plated finish and red soldermask
●DIL-32 board, standard 0.1" pin spacing. Can be mounted on a breadboard
●Measures approx. 1.7” x 0.8” (42mm x 20mm) and 0.062” (1.6mm) thick.
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MT-DB-U2 Manual
ATmega32U2 Features
●High Performance, Low Power AVR®8-Bit Microcontroller
●Advanced RISC Architecture
125 Powerful Instructions – Most Single Clock Cycle
32 x 8 General Purpose Working Registers
Fully Static Operation
Up to 16 MIPS Throughput at 16 Mhz
●Non-volatile Program and Data Memories
32K Bytes of In-System Self-Programmable Flash
1024 Bytes EEPROM
1024 Bytes Internal SRAM
Write/Erase Cycles: 10,000 Flash/ 100,000 EEPROM
Data retention: 20 years at 85°C/ 100 years at 25°C(1)
Optional Boot Code Section with Independent Lock Bits
In-System Programming by on-chip Boot Program
True Read-While-Write Operation
Programming Lock for Software Security
●USB 2.0 Full-speed Device with Interrupt on Transfer Completion
Complies fully with Universal Serial Bus Specification REV 2.0
48 MHz PLL for Full-speed Bus Operation: 12 Mbit/s data rate
Fully independant 176 bytes USB DPRAM for endpoint memory
Endpoint 0 for Control Transfers: from 8 up to 64-bytes
4 Programmable Endpoints:
IN or Out Directions
Bulk, Interrupt and IsochronousTransfers
Programmable maximum packet size from 8 to 64 bytes
Programmable single or double buffer
Suspend/Resume Interrupts
Microcontroller reset on USB Bus Reset without detach
USB Bus Disconnection on Microcontroller Request
●Peripheral Features
One 8-bit Timer/Counters with Separate Prescaler and Compare
(two 8-bit PWM channels)
One 16-bit Timer/Counter with Prescaler, Compare and Capture
(three 8-bit PWM channels)
USART with SPI master mode and hardware flow control (RTS/CTS)
Master/Slave SPI Serial Interface
Programmable Watchdog Timer with Separate On-chip Oscillator
On-chip Analog Comparator
Interrupt and Wake-up on Pin Change
●On Chip Debug Interface (debugWIRE)
●Special Microcontroller Features
Power-On Reset and Programmable Brown-out Detection
Internal Calibrated Oscillator
External and Internal Interrupt Sources
5 Sleep Modes: Idle, Powersave, Powerdown, Stby., and Ext. Stby.
●I/O and Packages
22 Programmable I/O Lines
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MT-DB-U2 Manual
QFN32 (5x5mm) / TQFP32 packages
●Operating Voltages
2.7 – 5.5V
●Operating temperature
Industrial (-40°C to +85°C)
●Maximum Frequency
8 MHz at 2.7V - Industrial range
16 MHz at 4.5V - Industrial range
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MT-DB-U2 Manual
MT-DB-U2 Hardware
MT-DB-U2 Hardware
Layout / Header Pins
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MT-DB-U2 Manual
Solder Jumpers
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MT-DB-U2 Manual
Pin Descriptions
Pin Description
Gnd Ground
5V, Vbus 5V output from USB Vbus. Vbus pin and 5V pin are tied together.
Vcc Voltage input pin. Use solder jumper J8 to configure. 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 microcontroller internal 3.3V regulator. This pin is
connected to Ucap on the microcontroller.
X2 (C0) This pin can be connected to the XTAL2 pin of the microcontroller using
jumper J7. This is useful if pin C0 is used as GPIO (if external clock is
used). This pin is disconnected by default (onboard crystal is used).
X1 This pin can be connected to the XTAL1 pin of the microcontroller using
jumper J7. This is useful if an external clock is used. This is also useful for
HV programming or recovery from incorrectly set fuses. This pin is
disconnected by default (onboard crystal is used).
C2 GPIO pin (Port C) Consult datasheet for functionality.
D0 - D7 GPIO pins (Port D) Consult datasheet for functionality.
D0 / LED The green status LED is connected to this pin when solder jumper J2 is
set. The LED is connected to ground through a 240 ohm resistor. The user
application is free to use this LED. Drive the pin high to turn on the LED.
D7 / HWB This pin is connected to the bootloader jumper (HWB). 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.
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. If jumper J1
is set to ISP In, then RST is also connected to pin 5 of the ISP header.
B0 - B6 GPIO pins (Port B) Consult datasheet for functionality.
B7 PWM filter C output (OC.1C) or pin B7, depending on jumper
configuration.
C4, C7 GPIO pins (Port C) Consult datasheet for functionality.
C5 PWM filter B output (OC.1B) or pin C5, depending on jumper
configuration.
C6 PWM filter A output (OC.1A) or pin C6, depending on jumper
configuration.
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MT-DB-U2 Manual
D+, D- USB data pins. Can be used for panel-mount connectors.
PWM Filters
There are three PWM filters, which can be used to smooth out a PWM square wave
into an analog voltage (with some ripple). The outputs of these filters can be connected to
header pins C6, C5, and B7 using solder jumpers J4, J5, and J3 respectively (factory default).
The filters consist of a 1K resistor and 100nF capacitor. The cutoff frequency is:
f3db=1/2RC=1/21K∗100nF=1/20.0001=1600Hz
This is a first-order low-pass filter that can output levels from 0V to Vcc. All three filter
inputs are connected to the 16-bit timer 1 output compare pins (OC.1A, OC.1B, and OC.1C).
The filter inputs are always connected to the microcontroller. Therefore, if the solder jumpers
are configured to connect the microcontroller pins directly to the header pins, there will be
some loading on the pin (1K resistor in series with a 100nF capacitor to ground).
Clock Source
By default, a 16 MHz crystal is installed and connected to the XTAL pins of the
Atmega32U2. This 16 Mhz clock must be divided by 2 in software if the Vcc voltage is less
than 4.5V. If an external clock is is used, solder jumper J6 can be switched to connect the
microcontroller pin directly to header pin rather than the onboard crystal. An external clock
signal can then be applied to pin X1 (XTAL1). This will also free up microcontroller pin C0
(XTAL2), which can be configured in the microcontroller as a GPIO pin and routed to header
pin X2 by switching solder jumper J7.
HWB Jumper / RESET button / LED
The HWB Jumper is used to select either the bootloader or user application. The pin is
sampled after reset or power-up. Note that the hardware HWB function of the ATmega32U2 is
disabled. That is, the HWBE fuse is disabled. The bootloader startup code is always run after reset or
power-up (BOOTRST fuse is set). The code samples the state of the HWB pin. If the pin is low, the
bootloader continues to run. If the pin is high, the user application is run. The green LED will pulse on
and off using a continuously changing PWM period when the DFU bootloader is running. If the
preinstalled demo program is running, it will be lit when USB is connected. Otherwise, the state of the
LED is controlled by the user application. The bootloader always runs at 8 MHz, which is compatible
with lower voltages. The user may set the cpu speed to 16MHz in software, if running at 5V.
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MT-DB-U2 Manual
Jumper Mode Driver
No User Program CDC (COM port) (optional)
Yes Bootloader Program CDC Serial/DFU Bootloader
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.
The pins associated with the LED, jumper, and reset button are all routed to header pins. The
LED can be disconnected by unsoldering jumper J2. The jumper is connected to pin D7 on one side
and to ground through a 240 ohm resistor on the other side. There is a 10K pullup on the reset line.
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 J1. This allows the MT-DB-U2 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. When using the ISP header, you
may need to remove the HWB jumper to allow the ISP connector to fit.
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