Atmel STK525 Installation manual

STK525
.............................................................................................
Hardware User Guide

STK525 Hardware User Guide User Guide 1
7608A–AVR–04/06
Section 1
Introduction...........................................................................................1-3
1.1 Overview...................................................................................................1-3
1.2 STK525 Starter Kit Features.....................................................................1-4
Section 2
Using the STK525.................................................................................2-6
2.1 Overview...................................................................................................2-6
2.2 Power Supply............................................................................................2-7
2.3 RESET....................................................................................................2-10
2.4 AT90USBxxx AVR Microcontroller..........................................................2-11
2.5 Serial Links .............................................................................................2-11
2.6 On-board Resources...............................................................................2-14
2.7 STK500 Resources.................................................................................2-19
2.8 In-System Programming .........................................................................2-20
2.10 Test Points..............................................................................................2-23
2.11 Configuration Pads .................................................................................2-24
2.12 Solder Pads ............................................................................................2-25
Section 3
Troubleshooting Guide .......................................................................3-26
Section 4
Technical Specifications .....................................................................4-27
Section 5
Technical Support...............................................................................5-28
Section 6
Complete Schematics.........................................................................6-29

STK525 Hardware User Guide 1-3
7608A–AVR–04/06
Section 1
Introduction
Congratulation for acquiring the AVR® STK525 Starter Kit. This kit is designed to give
designers a quick start to develop code on the AT90USBxxx and for prototyping and
testing of new designs.
1.1 Overview
This document describes the STK525 dedicated to the AT90USBxxx AVR
microcontroller. This board is designed to allow an easy evaluation of the product using
demonstration software.
To complement the evaluation and enable additional development capability, the
STK525 can be plugged into the Atmel STK500 Starter Kit Board in order to use the
AT90USBxxx with advanced features such as variable VCC, variable VRef, variable
XTAL, etc. and supports all AVR development tools.
To increase its demonstrative capabilities, this stand alone board has numerous on-
board resources (USB, RS232, joystick, data-flash, microphone and temperature
sensor).
This user guide acts as a general getting started guide as well as a complete technical
reference for advanced users.

Introduction
1-4 STK525 Hardware User Guide
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Figure 1-1 . STK525 Board
1.2 STK525 Starter Kit Features
The STK525 provides the following features:
 AT90USBxxx TQFP device (2.7V<Vcc<5.5V),
 AVR Studio® software interface (1),
 USB software interface for Device Firmware Upgrade (DFU bootloader) (2)
 STK500 compatible
 Power supply flagged by “VCC-ON” LED:
– regulated 3 or 5V,
– from an external power connector,
– from the USB interface (USB device bus powered application),
– from STK500 (2),
 ISP connector for on-chip ISP,
 JTAG connector:
– for on-chip ISP,
– for on-chip debugging using JTAG ICE,
 Serial interfaces:
– 1 USB full/low speed device/host interface
– RS-232C ports with RTS/CTS handshake lines,
 On-board resources:
– 4+1-ways joystick,
–4LEDs,
– temperature sensor,
– microphone,
– serial dataflash memory,

Introduction
STK525 Hardware User Guide 1-5
7608A–AVR–04/06
 On-board RESET button,
 On-board HWB button for force bootloader section execution at reset.
 System clock:
– external clock from STK500 expand connectors
– 8 MHz crystal,
 Numerous access points for test.
Notes: 1. The STK525 is supported by AVR Studio®, version 4.12SP2 or higher. For up-to-date
information on this and other AVR tool products, please consult our web site. The
newest version of AVR Studio®, AVR tools and this User Guide can be found in the
AVR section of the Atmel web site, http://www.atmel.com.
2. ATMEL Flip®, In System Programming Version 3 or Higher shall be used for Device
Firmware Upgrade. Please consult Atmel web site to retrieve the latest version of Flip
and the DFU bootloader Hex file if needed.

STK525 Hardware User Guide 2-6
7608A–AVR–04/06
Section 2
Using the STK525
This chapter describes the board and all its features.
2.1 Overview
Figure 2-1 . STK525 Overview
USB MiniAB RS232 JTAG ISP External Power
Joystick Potentiometer ResetCrystal Microphone
STK500 Expand0 STK500 Expand1
Data Flash
LEDS
Vcc Src.
Setting
TQFP64 Socket
Pin1
C Sensor
Vbus Gen.
Setting
Bootloader
Activation

Using the STK525
STK525 Hardware User Guide 2-7
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2.2 Power Supply
The on-board power supply circuitry allows various power supply configurations.
2.2.1 Power Supply Sources
The power supply source can come from three different (3) and exclusive sources:
 USB connector,
 JACK PWR connector (J6, See Figure 2-2),
 STK500
USB powered: When used as a USB device bus powered application, the STK525 can be powered via
the USB VBUS power supply line.
JACK PWR connector: – Need of a male JACK outlet,
– Input supply from 9 up to 15V (1) DC,
– No specific polarization (2) is required.
Figure 2-2 . JACK PWR Connector (J6)
Figure 2-3 . Male JACK Outlet and Wires
STK500 Powered: (c.f. “STK500 Resources” on page 19).
Notes: 1. 15V is the maximum level limitation of an unidirectional transit diode.
2. There is a diode (bridge) voltage level between the negative output of the power
supply and the STK525 “GND”. This could introduce some gap of voltage during
measurement and instrumentation.
3. Caution: Do not mount more than one power supply source on STK525.
+
-

Using the STK525
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2.2.2 Power Supply Setting
Table 2-1 . Power Supply(1) Setting
Notes: 1. Caution: The STK500 has its own “ON/OFF” switch
Vcc Source
Jumper position VCC power supply value Comments View
VBUS 5 VBUS
(4,7V to 5.0V)
This is the default configuration.
This should be used for a typicalUSB
device “bus powered” application.
In this mode, the STK525 is powered
directly from the USB bus, and no
other external power supply is
required.
REG 5 5V
This configuration can be used for a
USB “self powered” device
application” or when operating has a
USB host.
To use this configuration an external
power supply must be connected to
J6 connector.
REG 3.3 3.3V
This configuration allows the STK525
to be used in a 3V range application.
This configuration can be used with
both device or host mode USB
applications.
To use this configuration an external
power supply must be connected to
J6 connector.
STK Depends on STK500 VTG
setting
This configuration allows the STK525
to be used with an STK500 board.
In this mode, the STK525 power
supply is generated and configured
according to the “VTG” parameter of
the STK500 (1).
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK
VCC
Source
Reg 5
Reg 3.3
VBUS 5
STK

Using the STK525
STK525 Hardware User Guide 2-9
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2.2.3 VBUS Generator Setting
When using the AT90USBxxx microcontroller in USB host mode. The STK525 should
provide a 5V power supply over the VBUS pin of its USB mini AB connector.
A couple of transistors on the STK525 allows the UVCON pin of the AT90USBxxx to
control the VBUS generation (See Figure 2-4). In this mode the STK525 is powered by
external power supply source (J6 or STK500 expand0/1 connectors). JP7 allows to
select the 5V source used by the VBUS generator.
Figure 2-4 . VBUS generator schematic
Table 2-2 . VBUS Generator Setting
M1
FDV304P/FAI
R33
100k
VTG
STK
Ext
Q2
BC847B -
C34
4.7uF
2
1
3
JP7
VBUS gen R32
10k
UVCON
VBUS
“Vbus Gen”
Jumper position STK525 power supply Comments View
“Ext” External power supply from J6
This is the default configuration.
The VBUS generator source is the
on-board 5V regulator.
“Stk” External power supply from
Expand0/1 (connected to a STK500)
The VBUS generator source is the
STK500.
Note:
The “Vtarget” setting of STK500
should be set to “5V”.
Vbus
Gen
Ext
Stk
Vbus
Gen
Ext
Stk

Using the STK525
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2.2.4 “POWER-ON“ LED
The POWER-ON LED is always lit when power is applied to STK525 regardless of
power supply source and the regulation.
Figure 2-5 . “VCC-ON” LED
2.3 RESET
Although the AT90USBxxx has its on-chip RESET circuitry (c.f. AT90USBxxx
Datasheet, section “System Control and Reset), the STK525 provides the AT90USBxxx
a RESET signal which can come from 3 different sources:
2.3.1 Power-on RESET
The on-board RC network acts as power-on RESET.
2.3.2 RESET Push Button
By pressing the RESET push button on the STK525, a warm RESET of the
AT90USBxxx is performed.
Figure 2-6 . RESET Push Button (RST) Implementation

Using the STK525
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2.3.3 STK500 RESET
(c.f. “RESET from STK500” on page 20)
2.4 AT90USBxxx AVR Microcontroller
2.4.1 Main Clock XTAL
To use the USB interface of the AT90USBxxx, the clock source should always be a
crystal or external clock oscillator (the internal 8MHz RC oscillator cannot be used to
operate with the USB interface). Only the following crystal frequency allows proper USB
operations: 2MHz, 4MHz, 6MHz, 8MHz, 12MHz, 16MHz. The STK525 comes with a
default 8MHz crystal oscillator.
When closing STKX1 and STKX2 switches, and STK525 is connected to an STK500,
the STK525 can operate with the “STK500 Osc” frequency parameter.
2.4.2 Analog Power Supply
AVCC By default, AVCC is equivalent to VCC.
ANA REF By default, AREF is an output of AT90USBxxx.
An external AREF source can be chosen (c.f. “STK500 Resources” on page 19).
2.5 Serial Links
2.5.1 USB
The STK525 is supplied with a standard USB mini A-B receptacle. The mini AB
receptacle allows to connect both a mini A plug or a mini B plug connectors.
Figure 2-7 . USB mini A-B Receptacle
When connected to a mini B plug, the AT90USBxxx operates as an “USB device” (the
ID pin of the plug is unconnected) and when connected to a mini A plug, the
AT90USBxxx operates as a “USB host” (the ID pin of the plug is tied to ground).

Using the STK525
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2.5.2 RS-232C
The AT90USBxxx is a microcontroller with an on-chip USART peripheral (USART1).
Only the asynchronous mode is supported by the STK525.
The STK525 is supplied with a RS-232 driver/receiver. One female DB9 connector
assumes the RS-232 connections.
Figure 2-8 . RS-232 DB9 Connector
Figure 2-9 . RS-232 DB9 Connections
Figure 2-10 . Typical PC Connection Layout
1
RS-232 DB9 front view
pin 2
569 234 78
RS-TxD
pin 3 RS-RxD
pin 4
pin 6
pin 5 GND
pin 7 RS-CTS
pin 8 RS-RTS
STK525 / RS-232 DB9 PC / DB9 serial port
Pin No
(COM1 or COMx)
Function Pin No Function
2TxD (AT90USBxxx)
5GND
2
3RxD (PC) TxD (PC)3RxD (AT90USBxxx) 5GND
7CTS (AT90USBxxx) 7
8RTS (PC) CTS (PC)8 RTS ( AT90USBxxx )
If Hardware Data Flow Control

Using the STK525
STK525 Hardware User Guide 2-13
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The STK525 USART implementation allows an optional hardware flow control that can
be enabled thanks to SP4, SP5, SP7, SP8 solder pads (See Figure 2-11).
Figure 2-11 . USART Schematic
Table 2-3 . UART Settings
Note: 1. Tx reference: STK525 source, Rx reference: STK525 destination
Mode Solder Pads
Configuration DB9 Connection (1)
Software Data Flow
Control
(default configuration)
SP4: open
SP5: open
SP7: open
SP8: open
Tx
Rx Pin 2 Pin 3
Optional
Hardware Flow Control
SP4: close
SP5: close
SP7: close
SP8: close
Tx
Rx
CTS
RTS
Pin 2
Pin 3
Pin 7
Pin 8
5
9
4
8
3
7
2
6
1
10
11
P1
SUB-D9 FEMALE
RS232
RS232 Interface
RS-CTS
VCC
CTS
RTS
.
11 .
12
.
10
.
9.8
.7
.13
.14
.
15 .16
C1+
1V+ 2
C1-
3
C2+
4
C2-
5V- 6
RS 232TTL
GND
VCC
U3
MAX3232
RS232 BUFFER
C17
100nF
C16
100nF C18
100nF
C19
100nF
RxDPD2
RS-TxDRS-TxDRS-TxDRS-TxDRS-TxDRS-TxDRS-TxDRS-TxD
RS-RxD
PD[7..0]
SP4
SP5
PD1
PD0
PD3 TXD
SP7
SP8
RS-RTS

Using the STK525
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2.6 On-board Resources
2.6.1 Joystick
The 4+1 way joystick offers an easy user interface implementation for a USB application
(it can emulate mouse movements, keyboard inputs, etc.).
Pushing a push-button causes the corresponding signal to be pulled low, while releasing
(not pressed) causes an H.Z state on the signal. The user must enable internal pull-ups
on the input pins, removing the need for an external pull-up resistors on the push-button.
Figure 2-12 . Joystick Schematic
Figure 2-13 . Joystick Implementation
2.6.2 LEDs
The STK525 includes 4 green LEDs implemented on one line. They are connected to
the high nibble of “Port D” of AT90USBxxx (PORTD[4..7]).
To light On a LED, the corresponding port pin must drive to high level. To light Off a
LED, the corresponding port pin must drive a low level. It is the opposite method used in
STK500.
Select 5
Left 7
Up 3
Right 6
Down 4
Com1
1
Com2
2
SW3
TPA511G
PE[7..0]
PB[7..0]
PB5
PB6
PB7
PE4
PE5
Select 5
Left 7
Up 3
Right 6
Down 4
Com1
1
Com2
2
SW3
TPA511G
PE[7..0]
PB[7..0]
PB5
PB6
PB7
PE4
PE5
Select 5
Left 7
Up 3
Right 6
Down 4
Com1
1
Com2
2
SW3
TPA511G
PE[7..0]
PB[7..0]
PB5
PB6
PB7
PE4
PE5

Using the STK525
STK525 Hardware User Guide 2-15
7608A–AVR–04/06
Figure 2-14 . LEDs Implementation Schematic
In-line Grouped LEDs
D2TOPLED LP M676
LED0(green)
D3TOPLED LP M676
LED1(green)
D4TOPLED LP M676
LED2(green)
D5TOPLED LP M676
LED3(green)
R121k
R131k
R141k
R151k
PD4
PD5
PD7
PD[7..0]
PD6

Using the STK525
2-16 STK525 Hardware User Guide
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2.6.3 Temperature Sensor
The temperature sensor uses a thermistor (R18), or temperature-sensitive resistor. This
thermistor has a negative temperature coefficient (NTC), meaning the resistance goes
up as temperature goes down. Of all passive temperature measurement sensors,
thermistors have the highest sensitivity (resistance change per degree of temperature
change). Thermistors do not have a linear temperature/resistance curve.
The voltage over the NTC can be found using the A/D converter (connected to channel
0). See the AT90USBxxx datasheet for how to use the ADC. The thermistor value (RT)
is calculated with the following expression:
Where: RT= Thermistor value (Ω) at Ttemperature (°Kelvin)
RH= Second resistor of the bridge -100 KΩ±10% at 25°C
VADC0 = Voltage value on ADC-0 input (V)
VCC = Board power supply
The NTC thermistor used in STK525 has a resistance of 100 KΩ±5%at 25°C (T0) and a
beta-value of 4250 ±3%. By the use of the following equation, the temperature (T) can
be calculated:
Where: RT= Thermistor value (Ω) at Ttemperature (°Kelvin)
ß= 4250 ±3%
R0= 100 KΩ±5% at 25°C
T0= 298 °K (273 °K + 25°K)
The following cross table also can be used. It is based on the above equation.
Table 2-4 . Thermistor Values versus Temperature
Temp.
(°C) RT
(KΩ)Temp. (°C) RT (KΩ)Temp. (°C) RT (KΩ)Temp. (°C) RT (KΩ)
-20 1263,757 10 212,958 40 50,486 70 15,396
-19 1182,881 11 201,989 41 48,350 71 14,851
-18 1107,756 12 191,657 42 46,316 72 14,329
-17 1037,934 13 181,920 43 44,380 73 13,828
-16 973,006 14 172,740 44 42,537 74 13,347
-15 912,596 15 164,083 45 40,781 75 12,885
-14 856,361 16 155,914 46 39,107 76 12,442
-13 803,984 17 148,205 47 37,513 77 12,017
-12 755,175 18 140,926 48 35,992 78 11,608
-11 709,669 19 134,051 49 34,542 79 11,215
-10 667,221 20 127,555 50 33,159 80 10,838
RTRHVADC0 ⋅()VCC VADC0 – ()⁄=
Tβ
RT
R0
-------
ln
⎝⎠
⎛⎞
β
T0
------+
-------------------------------=

Using the STK525
STK525 Hardware User Guide 2-17
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Figure 2-15 . Thermistor Schematic
2.6.4 Microphone
The STK525 provides an electret microphone associated with its required preamplifier
(See Figure 2-16), the interface is connected to ADC channel 2 of the AT90USBxxx
microcontroller.
-9 627,604 21 121,414 51 31,840 81 10,476
-8 590,613 22 115,608 52 30,580 82 10,128
-7 556,056 23 110,116 53 29,378 83 9,793
-6 523,757 24 104,919 54 28,229 84 9,471
-5 493,555 25 100,000 55 27,133 85 9,161
-4 465,300 26 95,342 56 26,085 86 8,863
-3 438,854 27 90,930 57 25,084 87 8,576
-2 414,089 28 86,750 58 24,126 88 8,300
-1 390,890 29 82,787 59 23,211 89 8,035
0 369,145 30 79,030 60 22,336 90 7,779
1 348,757 31 75,466 61 21,498 91 7,533
2 329,630 32 72,085 62 20,697 92 7,296
3 311,680 33 68,876 63 19,930 93 7,067
4 294,826 34 65,830 64 19,196 94 6,847
5 278,995 35 62,937 65 18,493 95 6,635
6 264,119 36 60,188 66 17,820 96 6,430
7 250,134 37 57,576 67 17,174 97 6,233
8 236,981 38 55,093 68 16,556 98 6,043
9 224,606 39 52,732 69 15,964 99 5,860
Temp.
(°C) RT
(KΩ)Temp. (°C) RT (KΩ)Temp. (°C) RT (KΩ)Temp. (°C) RT (KΩ)
Temperature
Sensor
R18
CP1
R16
100k
PF0
VCC

Using the STK525
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Figure 2-16 . Microphone interface schematic
2.6.5 Data Flash Memory
For mass-storage class demonstration purposes, the STK525 provides an on-chip serial
Flash memory (AT45DB321x) connected to the AT90USBxxx Serial Port Interface
(SPI).
The data-flash chip select signal is connected to PortB bit 4 of the AT90USBxxx (See
Figure 2-17).
Figure 2-17 . On-board data flash schematic
2.6.6 Potentiometer
The cursor of a potentiometer is connected to ADC channel 1 of the AT90USBxxx.
3.3V 3.3V
3.3V R23 100k
1
TP4
Mic
5
67
8 4
+
-
U4B
LMV358
3
21
8 4
+
-
U4A
LMV358
R27 0
R26 22k
R25 10k
R24 100k
+C25
1uF
R21
100k
R28
100k
C22 220pF
+
C24 4.7uF
R20
2.2k
MIC1
MICROPHONE
R22
100k
3.3V
BUSY
1
RESET
2
WP
3VCC 6
GND 7 CS
11
SCK
12
SI
13
SO
14
U2
AT45DB321C TSOP28
C15
100nF
PB[7..0]
R11
100k
PB4
3.3V
PB1
R10
100k RESET
PB2
PB3

Using the STK525
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2.7 STK500 Resources
Figure 2-18 . Connecting STK525 to the STK500 Board
Note: Caution: Do not mount an AVR microcontroller on the STK500 board when STK525 is
plugged on STK500.
2.7.1 Supply Voltage from STK500
The AVR supply voltage coming from STK500 (VTG) can also be controlled from AVR
Studio®.
 The supply voltage coming from STK500 is controlled by power supply circuitry of
the STK525. Refer to Table 2-1 on page 8 to configure “Vcc Source” jumper.
2.7.2 Analog Reference Voltage from STK500
The AVR Analog Reference Voltage coming from STK500 (REF) can also be controlled
from AVR Studio®.
 JP3 should be closed

Using the STK525
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2.7.3 EXP.CON 0 & EXP.CON 1 Connectors
Figure 2-19 . EXP.CON 0 and EXP.CON 1 Connectors
2.7.4 Main Clock from STK500
The AVR clock frequency (external) coming from STK500 (XT1/XT2) can also be
controlled from AVR Studio®.
 “STKX1” and ”STKX2” jumpers should be closed
2.7.5 RESET from STK500
The AVR RESET coming from STK500 (NRST - EXP.CON 0) can also control the
STK525. STK525 is protected against +12V RESET pulse (parallel programing not
allowed for AT90USBxxx on STK525) coming from STK500.
2.8 In-System Programming
2.8.1 Programming with USB bootloader: DFU (Device Firmware Upgrade)
AT90USBxxx part comes with a default factory pre-programmed USB bootloader
located in the on-chip boot section of the AT90USBxxx. This is the easiest and fastest
way to reprogram the device directly over the USB interface. The “Flip” PC side
application available for free on Atmel website offers a flexible and user friendly
interface to reprogram the application over the USB bus.
EXP. CON 1
GND GND1 2
n.c. (AUXI0)n.c. (AUXO0)3 4
n.c. (CT7)n.c. (CT6)5 6
n.c. (CT5)n.c. (CT4)7 8
n.c. (CT3)n.c. (CT2)910
n.c. (CT1)n.c. (BSEL2)11 12
n.c. REF13 14
NRST PG215 16
PG1 PG017 18
GND GND19 20
PC7 PC623 24
VTG VTG21 22
PC5 PC425 26
PC3 PC227 28
PC1 PC029 30
PA7 PA631 32
PA5 PA433 34
PA3 PA235 36
PA1 PA037 38
GND GND39 40
GND GND1 2
n.c. (AUXI1)n.c. (AUXO1)3 4
n.c. (DATA7)n.c. (DATA6)5 6
n.c. (DATA5)n.c. (DATA4)7 8
n.c. (DATA3)n.c. (DATA2)910
n.c. (DATA1)n.c. (DATA0)11 12
n.c. (SI)n.c. (SO)1314
n.c. (SCK)n.c. (CS)1516
XT1 XT21718
VTG VTG1920
PB7 PB62324
GND GND2122
PB5 PB42526
PB3 PB22728
PB1 PB02930
PD7 PD63132
PD5 PD43334
PD3 PD23536
PD1 PD03738
GND GND3940
EXP. CON 0 Top View