CooCox Embedded Pi User manual

Embedded Pi User Manual
Rev. 1.0 Release: 2013-05-06
Website: www.coocox.org
Forum: forum.coocox.org
Techinal: [e-mail]
Market: [e-mail]

1
Catalog
Embedded Pi User Manual................................................................................................................0
Catalog ..............................................................................................................................................1
1 Introduction ..............................................................................................................................3
2 Key Features..............................................................................................................................4
3 Hardware Layout and Configuration .........................................................................................5
3.1 Block Diagram ...............................................................................................................5
3.2 ESD Precautions ............................................................................................................7
3.3 MCU ..............................................................................................................................8
3.4 Power ............................................................................................................................8
3.4.1 Power Supply.....................................................................................................8
3.4.2 Power Pins.........................................................................................................9
3.5 ArduinoTM Form-factor Compatibility............................................................................9
3.5.1 Power section..................................................................................................10
3.5.2 Analog section.................................................................................................10
3.5.3 ICSP/ SPI ..........................................................................................................10
3.5.4 Digital section..................................................................................................11
3.6 Embedded Pi Extended Interfaces ..............................................................................12
3.6.1 Custom Section................................................................................................12
3.6.2 Analog Section.................................................................................................13
3.6.3 Digital Section..................................................................................................13
3.7 Raspberry Pi Connector...............................................................................................14
3.8 Program the Embedded Pi ..........................................................................................15
3.8.1 ISP mode .........................................................................................................15
3.8.2 External Debugger Mode ................................................................................16
3.9 Button..........................................................................................................................17
3.10 LED ..............................................................................................................................17
3.11 System Clock Source....................................................................................................18
3.12 Jumper.........................................................................................................................18
4 Operation Modes ....................................................................................................................19
4.1 STM32/Standalone Mode ...........................................................................................19

2
4.1.1 Hardware connections ....................................................................................19
4.1.2 Software Resources.........................................................................................20
4.2 ST-Adapter Mode ........................................................................................................22
4.2.1 Hardware Connections....................................................................................23
4.2.2 Software Resources.........................................................................................24
4.3 Raspberry Pi Mode......................................................................................................24
4.3.1 Hardware Connections....................................................................................26
4.3.2 Software Resources.........................................................................................26
5 Getting Started........................................................................................................................27
6 Schematics ..............................................................................................................................41
7 References...............................................................................................................................45
7.1 Cortex-M3 ...................................................................................................................45
7.2 STM32 .........................................................................................................................45
7.3 CooCox ........................................................................................................................45
7.4 Raspberry Pi ................................................................................................................46
7.5 ArduinoTM ....................................................................................................................46

3
1Introduction
Figure 1-1 Embedded Pi board
Embedded Pi is a triple-play platform for Raspberry Pi, ArduinoTM and 32-bit embedded ARM.
Blending all three communities together, Embedded Pi helps you to get the most out of each
platform. The Embedded Pi is based on the STMicroelectronics STM32F103 MCU, and can
operate as a bridge between Raspberry Pi and ArduinoTM shields and in standalone mode as a
Cortex-M3 evaluation board.
Depending on the jumper placement on the Embedded Pi, you can select each of the three
modes of operation:
STM32/Standalone Mode
The Embedded Pi works as an ArduinoTM form-factor compatible mother board where the
STM32 controls the ArduinoTM shields directly without the use of Raspberry Pi. More…
ST-Adapter Mode
The STM32 controls the ArduinoTM shields, and the Raspberry Pi works as the GUI or
command line console to send commands/data to and receive data from the STM32. More…
Raspberry Pi Mode
The Embedded Pi works as a hardware connection bridge between Raspberry Pi and
ArduinoTM shields, allowing the Raspberry Pi to interface directly with existing ArduinoTM
shields. More…

4
The figure below shows the hardware connections of different modes.
Figure 1-2 Hardware connections of 3 operation modes
2Key Features
Provides Raspberry Pi with easy access to abundant ArduinoTM shields.
‒Compatible with both 5V and 3.3V ArduinoTM shields, selectable with jumpers
‒Hundreds of ArduinoTM shields available on the market enhance the control capability
of Raspberry Pi, e.g. to control Motor, sensors, etc.
Brings 32-bit ARM MCU into the world of ArduinoTM.
‒32-bit ARM Cortex-M3 STM32F103 MCU operating at 72MHz, with 128KB Flash, 20KB
RAM, motor control, USB, and CAN
‒Hundreds of ArduinoTM shields available on the market with extremely portable drivers
provided or to be shared by CooCox and CoFans
‒A complete set of FREE CooCox tools for ARM development
‒A common footprint next to ArduinoTM footprint for connection with expansion
daughter cards which will be developed by CooCox
Raspberry Pi and the STM32 MCU can work independently or in conjunction with each
other to control the ArduinoTM shields or other accessories.

5
3Hardware Layout and Configuration
3.1 Block Diagram
STM32
STM32
IO PWM PWM IO PWM IO TX RX
PWM- PWM+ PWM- PWM+ CTS2 RTS2 TX2 RX2
SCL SDA AREF GND SCK MISO MOSI SS PWM IO
SCL2 SDA2 IO IO SCK2 MISO2 MOSI2 SS2 CANTX CANRX
Embedded Pi Analog Input External InterfaceEmbedded Pi MCU ISP(Program Interface)
Arduino Power Interface Arduino ADC Interface
RPI Connecter
USB Micro-B
DC-005
(7V –16V)
STM32
Debug
Connecter
Bus Switch & 3V3/5V Voltage-level translate
IIC
SPI
UART
PWM
CAN
ADC
GPIO
IIC/SPI/UART/PWM/
ADC/GPIO/CAN
IIC/SPI/UART/
PWM/GPIO
Raspberry Pi
Connector
Embedded Pi On
Board MCU
Arduino-Compatible
Embedded Pi Board
3 Power Source
(auto Switch)
-----------------
External DC
USB
RPI_5V
Embedded Pi Extended Interfaces:
1 SPI, 1 I2C, 1 UART with Flow Ctrl,
2 Pairs PWM(+-),6 Analog Input,
1 CAN
Arduino Form-factor Compatible
Interfaces:
1SPI, 1I2C, 4PWM, 1 UART,
6 Analog Input
Figure 3-1 Hardware block diagram
Besides the ArduinoTM form-factor compatible interfaces onboard, Embedded Pi has some
additional SPI, IIC, UART interfaces, and some other extended interfaces like USB and CAN.
Users can use the MCU onboard or a connected Raspberry Pi to control ArduinoTM shields via the
ArduinoTM form-factor compatible interfaces. The following sections give a detailed introduction
of the operation modes and interfaces of Embedded Pi: 4 Operation Modes, 3.5 ArduinoTM
Form-factor Compatibility, 3.6 Embedded Pi Extended Interfaces, and 3.7 Raspberry Pi
Connector.
Embedded Pi has 3 power sources from which the power supply is auto-selected –USB
connection, an external DC power supply, or a Raspberry Pi. For more information, refer to 3.4
Power MCU.

6
Embedded Pi contains an ARM Cortex-M3 MCU STM32F103RBT6 which belongs to STM32 F1
series of mainstream MCUs.
The STM32 F1 is a series of mainstream MCUs covering the needs of a large variety of
applications in the industrial, medical and consumer markets. With this series of products, ST has
pioneered the world of ARM® Cortex™-M microcontrollers and set a milestone in the history of
embedded applications. High performance with first-class peripherals and low-power,
low-voltage operation is paired with a high level of integration at accessible prices with a simple
architecture and easy-to-use tools.
The features of STM32F103RBT6 are listed below:
32-bit with ARM Cortex-M3 core running at up to 72MHz.
128KB Flash for programming, 20KB SRAM.
Embedded Internal RC 8MHz and 32 kHz, Real-Time Clock.
16-bit Timers with Input Capture, Output Compare and PWM.
16-bit 6-ch Advanced Timer, 2 16-bit Watchdog Timers, SysTick Timer
Rich communication interfaces: 2 SPI, 2 I2C, 3 USART
USB 2.0 Full Speed Interface, CAN 2.0B Active
2 12-bit 16-ch A/D Converter
Figure 3-2 Embedded Pi board layout

7
GND
AREF
P
O
W
E
R
A
N
A
L
O
G
D
I
G
I
T
A
L
D
I
G
I
T
A
L
SPI
ID
0
15
ID
16
21
12
14
8
7
ID
9
10
11
13
1
6
3
5
42
3V3
VIN
5V
GND
NC
IOREF
RESET
GND
ID
22
27
ID
28
39
45
40
ID
3V3
RX1
NC
GND
BOOT0
BOOT1
RESET
TX1
NOTE:
1
25
2
26
Embedded Pi Extended
Interface
Arduino form-factor
compatible Interface
Raspberry Pi Interface
Figure 3-3 Pin IDs of the connectors
3.2 ESD Precautions
Please note that the Embedded Pi board comes without any
case/box and all components are exposed. Therefore, extra
attention must be paid to ESD (electrostatic discharge) precautions.
Please make sure there is no static interference when using the
board. Appropriate ESD protections must be taken and wearing
electrostatic equipment is recommended, such as wearing an
anti-static wristband.
ESD damage can range from subtle performance degradation to
complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes
could cause the device not to meet its published specifications.

8
3.3 MCU
Embedded Pi contains an ARM Cortex-M3 MCU STM32F103RBT6 which belongs to STM32 F1
series of mainstream MCUs.
The STM32 F1 is a series of mainstream MCUs covering the needs of a large variety of
applications in the industrial, medical and consumer markets. With this series of products, ST has
pioneered the world of ARM® Cortex™-M microcontrollers and set a milestone in the history of
embedded applications. High performance with first-class peripherals and low-power,
low-voltage operation is paired with a high level of integration at accessible prices with a simple
architecture and easy-to-use tools.
The features of STM32F103RBT6 are listed below:
32-bit with ARM Cortex-M3 core running at up to 72MHz.
128KB Flash for programming, 20KB SRAM.
Embedded Internal RC 8MHz and 32 kHz, Real-Time Clock.
16-bit Timers with Input Capture, Output Compare and PWM.
16-bit 6-ch Advanced Timer, 2 16-bit Watchdog Timers, SysTick Timer
Rich communication interfaces: 2 SPI, 2 I2C, 3 USART
USB 2.0 Full Speed Interface, CAN 2.0B Active
2 12-bit 16-ch A/D Converter
3.4 Power
3.4.1 Power Supply
Like the ArduinoTM mother boards, Embedded Pi can be powered via USB connection or with an
external DC power supply. Besides, a connected Raspberry Pi can also supply power to it. The
power supply is auto-selected from these 3 sources.
External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The
adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack.
Leads from a battery or other DC power supply can be inserted in the GND and VIN pin headers
of the POWER connector.
Raspberry Pi can supply power to Embedded Pi by connecting P1 on Raspberry Pi with the
Raspberry Pi connector (J5) on the Embedded Pi board via the 26-pin IDC cable in the package.
Embedded Pi can operate on an external supply of 6 to 20 volts. If supplied with less than 7V,
however, the 5V pin may supply less than five volts and the board may be unstable. If using more

9
than 12V, the voltage regulator may overheat and damage the board. The recommended range is
7 to 12 volts.
Note: Embedded Pi has 3.3V and 5V outputs for power supply, selectable by JP1. You need to
check and select which output to use every time when powering on the stacked ArduinoTM
shields.
3.4.2 Power Pins
The power pins of Embedded Pi are fully compatible with those of ArduinoTM form-factor and
listed as below:
VIN.
VIN is a voltage input pin connected to the input of the voltage conversion chip onboard
outputting 5V.
As VIN is connected to the power jack with a diode between them, the voltage on the pin
will be the same with the external power if any, ranging from 7 to 12V as recommended
above.
5V.
This is a 5V output pin with 2 voltage sources: 5V from USB connection, or an onboard
voltage conversion chip if using a 7 to 12V external DC power supply.
Note: Please do not input any external power directly to the pin, or your board can be
damaged.
3V3.
This is a 3.3V output pin extended from an onboard voltage conversion chip.
GND.
Ground pins.
3.5 ArduinoTM Form-factor Compatibility
Embedded Pi has ArduinoTM form-factor compatible interfaces onboard, which provide easy
access to controlling the ArduinoTM shields.
We have defined a digital ID for each signal as the name of the pin.