Waveshare DVK512 User manual

DVK512 User Manual Waveshare
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DVK512
User Manual
Copyright
All rights reserved by Waveshare Electronics Co., Ltd.
Not allow to modify, distribute, or copy without permission.
Revision History
Revision
Date
Description
V1.0
Aug. 18, 2014
Initial revision
V1.1
Nov. 13, 2014
Figures and tables update
V2.1
Nov. 27, 2014
Major update
V2.2
Dec. 03, 2014
Amendment
V2.3
Dec. 18, 2014
3.5inch LCD update
V2.4
Jan. 01, 2015
Amend Chap. 2.13
Overview
DVK512 is an expansion board designed for Raspberry Pi Model B+, integrates various
components and interfaces for connecting external accessory boards. It's ideal for Raspberry
Pi Model B+ evaluation and development.

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1. Pinheaders for connecting with the RPi
2. UART interface: easily connects to UART modules such as RS232, RS485, USB TO UART,
etc.
3. 8I/Os interface: easily connects to modules controlled by I/Os, such as 8 Push Buttons, Logic
Level Converter, Mix Board, etc.
4. SPI interface: easily connects to SPI modules such as AT45DBXX Dataflash, L3G4200D
Board, etc.
5. I2C interface: easily connects to I2C modules such as PCF8574 Expansion Board,
PCF8563 RTC Board, LSM303DLHC Board, etc.
6. Character LCD interface: for connecting character LCDs like LCD1602
7. USB connector: USB TO UART, supported by onboard converter CP2102
8. Power indicator
9. User LEDs
10. User Keys
11. Potentiometer: for LCD1602 contrast adjustment
12. RTC battery holder
13. PCF8563: onboard RTC chip
14. 32.768K crystal: RTC crystal
15. CP2102: onboard USB TO UART chip, for debugging
16. CP2102 jumper
17. RTC jumper
18. User LEDs jumper
19. User Keys jumper

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Contents
DVK512 User Manual................................................................................ 错误！未定义书签。
Copyright..........................................................................................................................1
Revision History ................................................................................................................1
Overview ..........................................................................................................................1
1. Basic operations ........................................................................................................4
1.1 System image file programming...................................................................4
1.2 Serial debugging environment deploying......................................................4
1.3 Debugging function disable (Serial port services as common serial port.........5
1.4 Debugging function enable..........................................................................6
1.5 How to work with a 3.5-inch LCD displayer...................................................6
1.6 3.5-inch LCD display switch to HDMI display .................................................8
1.7 HDMI display switch to 3.5-inch LCD display.................................................8
1.8 API source code ..........................................................................................8
2. DVK512 and expansion function Demos......................................................................9
2.1 LED Demo...................................................................................................9
2.2 Key Demo...................................................................................................9
2.3 8-channel Logic Level Convertor Demo.........................................................9
2.4 Joystick Demo...........................................................................................10
2.5 Buzzer and PWM.......................................................................................11
2.6 DS18B20 Demo.........................................................................................11
2.7 Infrared remote control ............................................................................12
2.8 LCD1602 Demo .........................................................................................13
2.9 PCF8563 RTC Demo...................................................................................13
2.10 PCF8591 AD Demo....................................................................................14
2.11 PCF8591 DA Demo ....................................................................................16
2.12 Acceleration of Gravity and Magnetic Sensors LSM303DLHC .......................16
2.13 Angular rate Sensor L3G4200D ..................................................................18
2.14 GPS Demo ................................................................................................18
2.15 USB WIFI Demo.........................................................................................19

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1. Basic operations
1.1 System image file programming
1) Run the CD provided with the module. Then, find out the file with the expansion
name .img under the directory of IMAGE and copy it to your PC (For the latest
system image file, please login the website:
http://www.waveshare.net/wiki/DVK512).
2) Format your TF card with the SDFormatter.exe.
Notices: The capability of TF card in used here should be more than 4GB. In this
operation, a TF card reader is also required, which has to be purchased
separately.
3) Start the Win32DiskImager.exe, and select the system image file copied into
your PC, then, click the button Write to program the system image file.
Figure 1: Programming the system image file with Win32DiskImager.exe
1.2 Serial debugging environment deploying
1) Connect your PC to the UART TO USB interface on DVK512 via a mini USB cable;
Notices: The USB part of the UART TO USB interface applied by DVK512 is a
mini USB interface, while the one on Raspberry Pi board is a micro USB
interface. Please take a note.
2) Install the cp2102_driver;
3) Start the software PuTTY.exe, and configure the following parameters:
Serial line: it is used to select corresponding serial port. The serial port in
used can be check by Device Manager.
Speed: it is used to set the Baud rate: 115200.
Connection type: this option should be set to Serial.

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Figure 2: PuTTY settings
4) And then, click the button Open.
5) After the system is started up, you should input following information: User
name: pi and Password: raspberry. Then, you can enter the serial terminal to
communicate with the Raspberry Pi.
Notices: In this document, the software PuTTY is always used to control the
Raspberry Pi via serial port communication, unless otherwise specified. When
a serial port is used for Raspberry Pi terminal debugging, it cannot service as a
common serial port any more, since it is occupied by system debugging
function. For more information, please refer to Section 1.3 and Section 1.4.
1.3 Debugging function disable (Serial port services as common serial port
After programming the system image file described above, you may find that the
serial port is set as terminal debugging output by default. In this case, you should
input corresponding commands on the terminal to disable the debugging
function of the serial port.
1) When using a LCD displayer, you should enter following command to disable the
debugging function of the serial port:
root@raspberrypi:/# DIS_UART-LCD
2) When using a HDMI displayer, you should enter following command to disable
the debugging function of the serial port:
root@raspberrypi:/# DIS_UART-HDMI
Notices: After executing any one of the commands above, the system will

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reboot automatically. After it rebooted, the terminal debugging function will
be disabled and the serial port will work as a common IO. However, you will
not be able to enter the terminal of the Pi via the serial port communication
any more. In this case, you can use SSH or connecting an external displayer to
the Pi to enter LXterninal.
3) Start a serial monitor (such as TCP232), and set the Baud rate: 115200. Then,
enter the terminal and input:
root@raspberrypi:/# UART_Test
Then, a string of character will be displayed in the serial monitor.
4) The data transmitted by the serial monitor will be displayed in the serial monitor.
Notices: Raspberry Pi can still transmit and receive data by running the serial
sample application, even though its debugging function of the serial port is
disabled. When the Raspberry Pi receives serial data from your PC, the
received data will be returned to PC and displayed in serial software.
5) Press the keys Ctrl+C on external keyboard to end the configuration.
1.4 Debugging function enable
If you need to enable the debugging function of the serial port again, please
following the steps described below:
1) When using a LCD displayer, you should enter following command to enable the
debugging function of the serial port:
root@raspberrypi:/# EN_UART-LCD
2) When using a HDMI displayer, you should enter following command to enable
the debugging function of the serial port:
root@raspberrypi:/# EN_UART-HDMI
1.5 How to work with a 3.5-inch LCD displayer
1) Power off the system, and connect a 3.5-inch LCD displayer to the Pi, as Figure 3
shows.

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Figure 3: Connection between a Raspberry Pi Model B+ and a 3.5-inch LCD displayer
2) Apply the system image described in Section 1.1, and power up the Pi.
3) Enter the following commands for touch screen calibration:
pi@raspberrypi:/$ su pi
pi@raspberrypi:/$ DISPLAY=:0.0 xinput_calibrator
4) After running these commands, there will be a prompt for four-point calibration
shown in the LCD screen. Click the points one by one to finish the touch
calibration. Then, the new calibration data will be displayed in the terminal, as
Figure 4 shows. Please get these data for future use.
Figure 4: The calibration data displayed in the terminal
5) Enter the following command to edit 99-calibration.conf:
pi@raspberrypi:/$ sudo nano /etc/X11/xorg.conf.d/99-calibration.conf
Figure 5: Editing 99-calibration.conf
6) Modify the data marked with red box in the Figure 5 to the new calibration data
displayed in the step 4), as Figure 6 shows.

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Figure 6: Modifying the data of Option “Calibration”
7) Press the keys Ctrl+X, and select the option Y to save the modification.
8) The modification will be valid after rebooting the system. Enter the following
command for system rebooting:
pi@raspberrypi:/$ sudo reboot
Notices: In case of inaccurate touch, please perform screen calibration again
and reboot the system.
1.6 3.5-inch LCD display switch to HDMI display
1) The default boot mode of the system image described in the Section 1.1 selects
3.5-inch LCD display. And there will be no output from the external HDMI
displayer if you apply one under this mode. In case that you want to use HDMI
display, please execute the following commands:
pi@raspberrypi:/$ sudo su
root@raspberrypi:/# HDMI-SYS-SHOW
2) The system will load the driver (wait several minutes). And the Raspberry Pi will
reboot automatically, when the driver download finished. After the module
rebooted, waiting more than 30 seconds, there will be information display on
the HDMI screen. And then, you will enter into Startx interface.
1.7 HDMI display switch to 3.5-inch LCD display
1) Enter the terminal, and input:
pi@raspberrypi:/$ sudo su
root@raspberrypi:/# LCD35-SYS-SHOW
2) The system will load the driver (wait several minutes). And the Raspberry Pi will
reboot automatically, when the driver download finished. After the module
rebooted, waiting more than 30 seconds, there will be information display on
the HDMI screen. And then, you will enter into Startx interface.
1.8 API source code
The API source code referred in this document can be found under the directory:
/home/pi/DVK512 (Since this directory is located in the system image file
described in Section 1.1, you should enter the Raspbian to find it).

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2. DVK512 and expansion function Demos
Before performing any operations described in this section, you should connect
DVK512 to RPi with onboard pin headers, unless otherwise specified.
2.1 LED Demo
1) Enter the terminal, and input:
root@ raspberrypi:/# LED_Test
2) The 4 LEDs will light up one by one;
3) Press the keys Ctrl+C to end the demo.
2.2 Key Demo
1) Enter the terminal, and input:
root@ raspberrypi:/# KEY_Test
2) The terminal will show whether there is key-press.
2.3 8-channel Logic Level Convertor Demo
1) Connect the 8-channel Logic Level Converter to the onboard 8I/Os interface, as
Figure 7 shows (Notices: The VCCA pin header on the Logic Level Converter
should be connected to the 3V3 pin header of the 8I/Os connector on DVK512).
Logic Level Converter
DVK512
VCCB
5V
GND
GND
B0
LED0
B1
LED2
B3
LED3
B4
KEY0
B5
KEY1
B6
KEY2
B7
DEY3
Table 1: Pin relationships between Logic Level Converter and DVK512

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Figure 7: The connection between Logic Level Converter and DVK512
2) Enter the terminal, and input:
root@ raspberrypi:/# 8-LOGIC
3) Press the KEY0-KEY3 on the DVK512, and the relative LED will light up.
4) Press the keys Ctrl+C to end the demo.
2.4 Joystick Demo
1) Connect the Mix Board to the 8I/Os interface;
2) Enter the terminal, and input:
root@ raspberrypi:/# JOYSTICK_Test
3) Press or move the joystick, the terminal will show the action
Notices: When using the 3.5 inch LCD displayer, the LCD displayer will disturb
PO value read from the joystick, while the joystick program will disturb the LCD
touch as well.