u-blox EVK-BMD-34/38: BMD-340-EVAL and BMD-341-EVAL

Overview

The BMD-340-EVAL and BMD-341-EVAL hardware provides support for the u-blox BMD-340 and BMD-341 Bluetooth 5.0 modules, based on the Nordic Semiconductor nRF52840 ARM Cortex-M4F CPU. the BMD-340 and BMD-341 are identical in operation except for the antenna. The BMD-340 has a PCB antenna while the BMD-341 has a U.FL connector. Both support the following devices:

  • ADC

  • CLOCK

  • FLASH

  • GPIO

  • I2C

  • MPU

  • NVIC

  • PWM

  • RADIO (Bluetooth Low Energy and 802.15.4)

  • RTC

  • Segger RTT (RTT Console)

  • SPI

  • UART

  • USB

  • WDT

BMD-340-EVAL

BMD-340-EVAL (Credit: u-blox AG)

More information about the BMD-340-EVAL, BMD-340 module, BMD-341-EVAL, and BMD-341 module can be found at the u-blox website 1. All of the Nordic Semiconductor examples for the nRF52840 DK (nrf52840dk_nrf52840) may be used without modification.

..note::

The BMD-340 and BMD-341 are identical except for the antennna. Throughout this board support package, the filenames utilize the ubx_bmd340eval_nrf52840.

Hardware

The BMD-340 on the BMD-340-EVAL (or BMD-341 on the BMD-341-EVAL) contains an internal high-frequency oscillator at 32MHz. There is also a low frequency (slow) oscillator of 32.768kHz. The BMD-340 and BMD-341 do not include the slow crystal; however, the BMD-340-EVAL and BMD-341-EVAL do.

Note

When targeting a custom design without a slow crystal, be sure to modify code to utilize the internal RC oscillator for the slow clock.

Supported Features

The BMD-340-EVAL and BMD-341-EVAL board configuration supports the following hardware features:

Interface

Controller

Driver/Component

ADC

on-chip

adc

CLOCK

on-chip

clock_control

FLASH

on-chip

flash

GPIO

on-chip

gpio

I2C(M)

on-chip

i2c

MPU

on-chip

arch/arm

NVIC

on-chip

arch/arm

PWM

on-chip

pwm

RADIO

on-chip

Bluetooth, IEEE 802.15.4

RTC

on-chip

system clock

RTT

Segger

console

SPI(M/S)

on-chip

spi

UART

on-chip

serial

USB

on-chip

usb

WDT

on-chip

watchdog

Other hardware features are not supported by the Zephyr kernel. See the u-blox website 1 for a complete list of BMD-340-EVAL and BMD-341-EVAL hardware features.

Connections and IOs

LED

  • LED1 (red) = P0.13

  • LED2 (red) = P0.14

  • LED3 (green) = P0.15

  • LED4 (green) = P0.16

  • D5 (red) = OB LED 1

  • D6 (green) = OB LED 2

Push buttons

  • BUTTON1 = SW1 = P0.11

  • BUTTON2 = SW2 = P0.12

  • BUTTON3 = SW3 = P0.24

  • BUTTON4 = SW4 = P0.25

  • BOOT = SW5 = boot/reset

External Connectors

BMD-340-EVAL pin-out

Note

The pin numbers noted below are referenced to the pin 1 markings on the BMD-340-EVAL or BMD-341-EVAL for each header

J-Link Prog Connector (J2)

PIN #

Signal Name

1

VDD

2

IMCU_TMSS

3

GND

4

IMCU_TCKS

5

V5V

6

IMCU_TDOS

7

Cut off

8

IMCU_TDIS

9

Cut off

10

IMCU_RESET

Debug OUT (J3)

PIN #

Signal Name

1

EXT_VTG

2

EXT_SWDIO

3

GND

4

EXT_SWDCLK

5

GND

6

EXT_SWO

7

N/C

8

N/C

9

EXT_GND_DETECT

10

EXT_RESET

Debug IN (J26)

PIN #

Signal Name

1

BMD-340_VCC

2

BMD-340_SWDIO

3

GND

4

BMD-340_SWDCLK

5

GND

6

BMD-340_SWO

7

N/C

8

N/C

9

GND

10

BMD-340_RESET

Auxiliary (J9)

PIN #

Signal Name

1

P0.10 / NFC2

2

P0.09 / NFC1

3

P0.08

4

P0.07

5

P0.06

6

P0.05 / AIN3

7

P0.01 / XL2

8

P0.00 / XL1

Auxiliary (J10)

PIN #

Signal Name

1

P0.11 / TRACED[2]

2

P0.12 / TRACED[1]

3

P0.13

4

P0.14

5

P0.15

6

P0.16

7

P0.17 / QSPI_CS

8

P0.18 / RESET

9

P0.19 / QSPI_CLK

10

P0.20 / QSPI_D0

11

P0.21 / QSPI_D1

12

P0.22 / QSPI_D2

13

P0.23 / QSPI_D3

14

P0.24

15

P0.25

16

P1.00 / TRACED[0]

17

P1.09 / TRACED[3]

18

No connection

Arduino Headers

Power (J5)

PIN #

Signal Name

BMD-34x Functions

1

VSHLD

N/A

2

VSHLD

N/A

3

RESET

P0.18 / RESET

4

VSHLD

N/A

5

V5V

N/A

6

GND

N/A

7

GND

N/A

8

N/C

N/A

Analog in (J8)

PIN #

Signal Name

BMD-34x Functions

1

A0

P0.03 / AIN1

2

A1

P0.04 / AIN2

3

A2

P0.28 / AIN4

4

A3

P0.29 / AIN5

5

A4

P0.30 / AIN6

6

A5

P0.31 / AIN7

Digital I/O (J7)

PIN #

Signal Name

BMD-34x Functions

1

D7

P1.08

2

D6

P1.07

3

D5

P1.06

4

D4

P1.05

5

D3

P1.04

6

D2

P1.03

7

D1 (TX)

P1.02

8

D0 (RX)

P1.01

Digital I/O (J6)

PIN #

Signal Name

BMD-34x Functions

1

SCL

P0.27

2

SDA

P0.26

3

AREF

P0.02 / AIN0

4

GND

N/A

5

D13 (SCK)

P1.15

6

D12 (MISO)

P1.14

7

D11 (MOSI)

P1.13

8

D10 (SS)

P1.12

9

D9

P1.11

10

D8

P1.10

J11

PIN #

Signal Name

BMD-34x Functions

1

D12 (MISO)

P0.14

2

V5V

N/A

3

D13 (SCK)

P0.15

4

D11 (MOSI)

P0.13

5

RESET

N/A

6

N/A

N/A

Programming and Debugging

Applications for the BMD-340-EVAL and BMD-341-EVAL board configurations can be built and flashed in the usual way (see Building an Application and Run an Application for more details); however, the standard debugging targets are not currently available.

Flashing

Follow the instructions in the Nordic nRF5x Segger J-Link page to install and configure all the necessary software. Further information can be found in Flashing. Then build and flash applications as usual (see Building an Application and Run an Application for more details).

Here is an example for the Hello World application.

First, run your favorite terminal program to listen for output.

$ minicom -D <tty_device> -b 115200

Replace <tty_device> with the port where the BMD-340-EVAL or BMD-341-EVAL can be found. For example, under Linux, /dev/ttyACM0.

Then build and flash the application in the usual way.

# From the root of the zephyr repository
west build -b ubx_bmd340eval_nrf52840 samples/hello_world
west flash

Debugging

Refer to the Nordic nRF5x Segger J-Link page to learn about debugging u-blox boards with a Segger J-LINK-OB IC.

Testing the LEDs and buttons in the BMD-340-EVAL and BMD-341-EVAL

There are 2 samples that allow you to test that the buttons (switches) and LEDs on the board are working properly with Zephyr:

samples/basic/blinky
samples/basic/button

You can build and flash the examples to make sure Zephyr is running correctly on your board. The button and LED definitions can be found in boards/arm/ubx_bmd340eval_nrf52840/ubx_bmd340eval_nrf52840.dts.

Using UART1

The following approach can be used when an application needs to use more than one UART for connecting peripheral devices:

  1. Add device tree overlay file to the main directory of your application:

    $ cat ubx_bmd340eval_nrf52840.overlay
&uart1 {
  compatible = "nordic,nrf-uarte";
  current-speed = <115200>;
  status = "okay";
  tx-pin = <14>;
  rx-pin = <16>;
};

    In the overlay file above, pin P0.16 is used for RX and P0.14 is used for TX

  2. Use the UART1 as device_get_binding("UART_1")

Overlay file naming

The file has to be named <board>.overlay and placed in the app main directory to be picked up automatically by the device tree compiler.

Selecting the pins

To select the pin numbers for tx-pin and rx-pin:

tx-pin = <pin_no>

Open the data sheet for the BMD-340 at the u-blox website 1, Section 2 ‘Pin definition’. In the table 3 select the pins marked ‘GPIO’. Note that pins marked as ‘Standard drive, low frequency I/O only (<10 kH’ can only be used in under-10KHz applications. They are not suitable for 115200 speed of UART.

Translate ‘Pin’ into number for Device tree by using the following formula:

pin_no = b\*32 + a

where a and b are from the Pin value in the table (Pb.a). For example, for P0.1, pin_no = 1 and for P1.0, pin_no = 32.