96Boards Aerocore2

Overview

The 96Boards Aerocore2 Mezzanine is based on the STMicroelectronics STM32F427VIT6 Cortex-M4 CPU primarily designed for use in drones. This board acts as a mezzanine platform for all 96Boards CE compliant boards. It can also be used as a standalone board.

96Boards Aerocore2

96Boards Aerocore2

Hardware

96Boards Aerocore2 provides the following hardware components:

  • STM32F427VIT6 in LQFP100 package

  • ARM® 32-bit Cortex®-M4 CPU with FPU

  • 168 MHz max CPU frequency

  • VDD from 1.7 V to 3.6 V

  • 2048 KB Flash

  • 256 KB SRAM

  • GPIO with external interrupt capability

  • 12-bit ADC with 16 channels

  • RTC

  • Advanced-control Timers (2)

  • General Purpose Timers (10)

  • Watchdog Timers (2)

  • USART/UART (4)

  • I2C (3)

  • SPI (3)

  • SDIO

  • USB 2.0 OTG FS

  • DMA Controller

More information about STM32F427VIT6 can be found here:

Supported Features

The Zephyr 96b_aerocore2 board configuration supports the following hardware features:

Interface

Controller

Driver/Component

NVIC

on-chip

nested vector interrupt controller

SYSTICK

on-chip

system clock

UART

on-chip

serial port

GPIO

on-chip

gpio

PINMUX

on-chip

pinmux

FLASH

on-chip

flash

SPI

on-chip

spi

I2C

on-chip

i2c

PWM

on-chip

timers / pwm

USB OTG FS

on-chip

USB device

ADC

on-chip

adc

More details about the board can be found at 96Boards website.

The default configuration can be found in boards/96boards/aerocore2/96b_aerocore2_defconfig

Connections and IOs

LED

  • LED1 / User1 LED = PE10

  • LED2 / User2 LED = PE9

External Connectors

Octal PWM Header (J1)

PIN #

Signal Name

STM32F427 Functions Pin

PIN #

Signal Name

Pin #

Signal Name

1

PWM4_CH1

PD12

2

5.0v

3

GND

4

PWM4_CH2

PD13

5

5.0v

6

GND

7

PWM4_CH3

PD14

8

5.0v

9

GND

10

PWM4_CH4

PD15

11

5.0v

12

GND

13

PWM5_CH1

PA0

14

5.0v

15

GND

16

PWM5_CH2

PA1

17

5.0v

18

GND

19

PWM5_CH3

PA2

20

5.0v

21

GND

22

PWM5_CH4

PA3

23

5.0v

24

GND

IO Header J11

PIN #

Signal Name

PIN #

Signal Name

1

PB9

2

PB8*

3

PC9

4

PB0

5

PE5

6

NA

7

PE6

8

NA

9

PC6

10

NA

11

PC7

12

NA

13

PC8

14

NA

15

PA8

16

GND

17

PA9

18

3v3

19

PA10

20

GND

  • PB8 is connected to a watchdog buzzer, It needs to be pulsed every 10 seconds to keep the buzzer silent.

IO Header J5

PIN #

Signal Name

STM32F427 Functions Pin

PIN #

Signal Name

STM32F427 Functions Pin

1

AGND

AGND

2

ADC1_13

PC3

3

ADC1_12

PC2

4

ADC1_11

PC1

5

I2C_SDA

PB11

6

GND

GND

7

I2C_SCL

PB10

8

VCC 3v3

VCC 3v3

9

NC

NC

10

NC

NC

11

NC

NC

12

NC

NC

13

UART_TX 7

PE8

14

GND

GND

15

UART_RX 7

PE7

16

GND

GND

17

UART_TX 2

PD5

18

GND

GND

19

UART_TX 2

PD6

20

GND

GND

21

NC

NC

10

NC

NC

23

NC

NC

10

NC

NC

25

SPI1_NIRQ

PC5

26

GND

GND

27

SPI1_CLK

PA5

28

SPI1_MISO

PA6

29

SPI1_CS0

PA4

30

SPI1_MOSI

PA7

31

CAN_TX

PD1

32

CANH

NC

33

CAN_RX

PD0

34

CANL

NC

GPS connector J15

PIN #

Signal Name

STM32F427 Functions Pin

1

V_OUT 5v

NC

2

UART1_TX

PB6

3

UART1_RX

PB7

4

VCC 3v3

NC

5

GND

GND

Spektrum connector J3

PIN #

Signal Name

STM32F427 Functions Pin

1

VCC 3v3

NC

2

GND

GND

3

UART8_RX

PE0

External Clock Sources

STM32F4 has one external oscillator. The frequency of the clock is 32.768 kHz. The internal 16MHz clock is used as the main clock.

Serial Port

96Boards Aerocore2 board has up to 4 U(S)ARTs. The Zephyr console output is assigned to USART7. Default settings are 115200 8N1.

I2C

96Boards Aerocore2 board has 1 I2C port. The default I2C mapping for Zephyr is:

  • I2C1_SCL : PB10

  • I2C1_SDA : PB11

SPI

96Boards Aerocore2 board has 1 SPI port. The default SPI mapping for Zephyr is:

  • SPI1_CS0 : PA4

  • SPI1_SCK : PA5

  • SPI1_MISO : PA6

  • SPI1_MOSI : PA7

USB

96Boards Aerocore2 board has a USB OTG dual-role device (DRD) controller that supports both device and host functions through its mini “OTG” USB connector. Only USB device functions are supported in Zephyr at the moment.

Programming and Debugging

There are 2 main entry points for flashing STM32F4X SoCs, one using the ROM bootloader, and another by using the SWD debug port (which requires additional hardware). Flashing using the ROM bootloader requires a special activation pattern, which can be triggered by using the BOOT0 pin. The ROM bootloader supports flashing via USB (DFU), UART, I2C and SPI. You can read more about how to enable and use the ROM bootloader by checking the application note AN2606, page 109.

Flashing

Installing dfu-util

It is recommended to use at least v0.8 of dfu-util. The package available in debian/ubuntu can be quite old, so you might have to build dfu-util from source.

Flashing an Application to 96Boards Aerocore2

Connect the micro-USB cable to the USB OTG/STM_CONSOLE Aerocore2 port and to your computer. The board should power ON. Force the board into DFU mode by keeping the BOOT0 switch pressed while pressing and releasing the RST switch.

The BOOT button is located at the back-side of the PCB.

Confirm that the board is in DFU mode:

$ sudo dfu-util -l
dfu-util 0.8
Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2014 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to [email protected]
Found DFU: [0483:df11] ver=2200, devnum=15, cfg=1, intf=0, alt=3, name="@Device Feature/0xFFFF0000/01*004 e", serial="3574364C3034"
Found DFU: [0483:df11] ver=2200, devnum=15, cfg=1, intf=0, alt=2, name="@OTP Memory /0x1FFF7800/01*512 e,01*016 e", serial="3574364C3034"
Found DFU: [0483:df11] ver=2200, devnum=15, cfg=1, intf=0, alt=1, name="@Option Bytes /0x1FFFC000/01*016 e", serial="3574364C3034"
Found DFU: [0483:df11] ver=2200, devnum=15, cfg=1, intf=0, alt=0, name="@Internal Flash /0x08000000/04*016Kg,01*064Kg,03*128Kg", serial="3574364C3034"
Found Runtime: [05ac:8290] ver=0104, devnum=2, cfg=1, intf=5, alt=0, name="UNKNOWN", serial="UNKNOWN"

You should see following confirmation on your Linux host:

$ dmesg
usb 1-2.1: new full-speed USB device number 14 using xhci_hcd
usb 1-2.1: New USB device found, idVendor=0483, idProduct=df11
usb 1-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-2.1: Product: STM32 BOOTLOADER
usb 1-2.1: Manufacturer: STMicroelectronics
usb 1-2.1: SerialNumber: 3574364C3034

Then build and flash an application. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b 96b_aerocore2 samples/hello_world
west flash

Connect a USB-TTL dongle to the UART_7 header port and to your computer. Run your favorite terminal program to listen for output.

$ minicom -D <tty_device> -b 115200

Replace <tty_device> with the port where the board 96Boards Aerocore2 can be found. For example, under Linux, /dev/ttyUSB0. The -b option sets baud rate ignoring the value from config.

Press the Reset button and you should see the following message in your terminal:

Hello World! arm