Nitrogen

96Boards Nitrogen

Overview

The 96Boards Nitrogen hardware provides support for the Nordic Semiconductor nRF52832 ARM Cortex-M4F CPU.

More information about the board can be found at the seeed BLE Nitrogen website. The Nordic Semiconductor Infocenter contains the processor’s information and the datasheet.

Hardware

96Boards Nitrogen provides the following hardware components:

nRF52832 microcontroller with 512kB Flash, 64kB RAM
ARM® 32-bit Cortex®-M4 CPU with FPU
Bluetooth LE
NFC
LPC11U35 on board SWD debugger
- SWD debugger firmware
- USB to UART
- Drag and Drop firmware upgrade
7 LEDs
- USR1, BT, PWR, CDC, DAP, MSD, Battery charge
SWD debug connectors
- nRF52832 SWD connector
- nRF52832 Uart connector
On board chip antenna
1.8V work voltage
2x20pin 2.0mm pitch Low speed connector

Supported Features

The 96b_nitrogen board supports the hardware features listed below.

on-chip / on-board: Feature integrated in the SoC / present on the board.
2 / 2: Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.
vnd,foo: Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

`96b_nitrogen/nrf52832` target

Type	Location	Description	Compatible
CPU	on-chip	ARM Cortex-M4F CPU1	`arm,cortex-m4f`
ADC	on-chip	Nordic Semiconductor nRF family SAADC node1	`nordic,nrf-saadc`
ARM architecture	on-chip	Nordic UICR (User Information Configuration Registers)1	`nordic,nrf-uicr`
	on-chip	Nordic nRF family BPROT (Block Protection)1	`nordic,nrf-bprot`
	on-chip	Nordic EGU (Event Generator Unit)6	`nordic,nrf-egu`
	on-chip	Nordic nRF family MWU (Memory Watch Unit)1	`nordic,nrf-mwu`
Audio	on-chip	Nordic PDM (Pulse Density Modulation interface)1	`nordic,nrf-pdm`
Clock control	on-chip	Nordic nRF clock control node1	`nordic,nrf-clock`
Clock control	on-chip	Nordic nRF high-frequency crystal oscillator (nRF52 series)1	`nordic,nrf52-hfxo`
Comparator	on-chip	Nordic nRF COMP (analog COMParator)1	`nordic,nrf-comp`
Counter	on-chip	Nordic nRF timer node5	`nordic,nrf-timer`
Cryptographic accelerator	on-chip	Nordic ECB (AES electronic codebook mode encryption)1	`nordic,nrf-ecb`
Cryptographic accelerator	on-chip	Nordic nRF family CCM (AES CCM mode encryption)1	`nordic,nrf-ccm`
Debug	on-chip	ARMv7 instrumentation trace macrocell1	`arm,armv7m-itm`
Flash controller	on-chip	Nordic NVMC (Non-Volatile Memory Controller)1	`nordic,nrf52-flash-controller`
GPIO & Headers	on-chip	NRF5 GPIOTE1	`nordic,nrf-gpiote`
	on-chip	NRF5 GPIO1	`nordic,nrf-gpio`
	on-board	GPIO Pin exposed on the 96Boards 1.8v low-speed header1	`linaro,96b-lscon-1v8`
I2C	on-chip	Nordic nRF family TWI (TWI master)1	`nordic,nrf-twi`
I2C	on-chip	Nordic nRF family TWIM (TWI master with EasyDMA)1	`nordic,nrf-twim`
I2S	on-chip	Nordic I2S (Inter-IC sound interface)1	`nordic,nrf-i2s`
Input	on-board	Group of GPIO-bound input keys1	`gpio-keys`
Interrupt controller	on-chip	ARMv7-M NVIC (Nested Vectored Interrupt Controller)1	`arm,v7m-nvic`
LED	on-board	Group of GPIO-controlled LEDs1	`gpio-leds`
Miscellaneous	on-chip	Nordic FICR (Factory Information Configuration Registers)1	`nordic,nrf-ficr`
Miscellaneous	on-chip	Nordic nRF family PPI (Programmable Peripheral Interconnect)1	`nordic,nrf-ppi`
MTD	on-chip	Flash node1	`soc-nv-flash`
MTD	on-board	Fixed partitions of a flash (or other non-volatile storage) memory1	`fixed-partitions`
Networking	on-chip	Nordic nRF family RADIO peripheral1	`nordic,nrf-radio`
Networking	on-chip	Nordic nRF family NFCT (Near Field Communication Tag)1	`nordic,nrf-nfct`
Pin control	on-chip	Nordic nRF family Pin Controller1	`nordic,nrf-pinctrl`
Power management	on-chip	Nordic nRF power control node1	`nordic,nrf-power`
PWM	on-chip	nRF PWM3	`nordic,nrf-pwm`
PWM	on-chip	nRFx S/W PWM1	`nordic,nrf-sw-pwm`
Regulator	on-chip	Nordic nRF5X regulator (fixed stage of the core supply)1	`nordic,nrf5x-regulator`
Retained memory	on-chip	Nordic GPREGRET (General Purpose Register Retention) device2	`nordic,nrf-gpregret`
RNG	on-chip	Nordic nRF family RNG (Random Number Generator)1	`nordic,nrf-rng`
RTC	on-chip	Nordic nRF RTC (Real-Time Counter)3	`nordic,nrf-rtc`
Sensors	on-chip	Nordic nRF family TEMP node1	`nordic,nrf-temp`
Sensors	on-chip	Nordic nRF quadrature decoder (QDEC) node1	`nordic,nrf-qdec`
Serial controller	on-chip	Nordic nRF family UART1	`nordic,nrf-uart`
SPI	on-chip	Nordic nRF family SPI (SPI master)1 2	`nordic,nrf-spi`
SRAM	on-chip	Generic on-chip SRAM1	`mmio-sram`
Timer	on-chip	ARMv7-M System Tick1	`arm,armv7m-systick`
Watchdog	on-chip	Nordic nRF family WDT (Watchdog Timer)1	`nordic,nrf-wdt`

Pin Mapping

LED

LED1 / User LED (green) = P0.29
LED2 / BT LED (blue) = P0.28

Push buttons

BUTTON = SW1 = P0.27

External Connectors

Low Speed Header

PIN #	Signal Name	nRF52832 Functions
1	GND	GND
3	UART CTS	P.014 / TRACEDATA[3]
5	UART TX	P0.13
7	UART RX	P0.15 / TRACEDATA[2]
9	UART RTS	P0.12
11	UART TX	P0.13
13	UART RX	P0.15 / TRACEDATA[2]
15	P0.22	P0.22
17	P0.20	P0.20
19	N/A	N/A
21	N/A	N/A
23	P0.02	P0.02
25	P0.04	P0.04
27	P0.06	P0.06
29	P0.08	P0.08
31	P0.16	P0.16
33	P0.18	P0.18
35	VCC
37	USB5V
39	GND	GND

PIN #	Signal Name	nRF52832 Functions
2	GND	GND
4	PWR BTN
6	RST BTN	P0.21 / RESET
8	P0.26	P0.26
10	P0.25	P0.25
12	P0.24	P0.24
14	P0.23	P0.23
16	N/A	N/A
18	N/A	PC7
20	N/A	PC9
22	N/A	PB8
24	P0.03	P0.03
26	P0.05	P0.05
28	P0.07	P0.07
30	P0.11	P0.11
32	P0.17	P0.17
34	P0.19	P0.19
36	NC
38	NC
40	GND	GND

More detailed information about the connectors can be found in 96Boards IE Specification.

System Clock

nRF52 has two external oscillators. The frequency of the slow clock is 32.768 kHz. The frequency of the main clock is 32 MHz.

Serial Port

96Boards Nitrogen has one UART, which is used as Zephyr console. Default settings is 115200 8N1.

I2C

96Boards Nitrogen has one I2C. The default I2C mapping for Zephyr is:

I2C0_SCL : P0.22
I2C0_SDA : P0.20

SPI

96Boards Nitrogen has one SPI. The default SPI mapping for Zephyr is:

SPI0_NSS : P0.24
SPI0_SCK : P0.26
SPI0_MISO : P0.25
SPI0_MOSI : P0.23

Flashing Zephyr onto 96Boards Nitrogen

The 96Boards Nitrogen board can be flashed via the CMSIS DAP interface, which is provided by the micro USB interface to the LPC11U35 chip.

Using the CMSIS-DAP interface, the board can be flashed via the USB storage interface (drag-and-drop) and also via pyOCD.

To use pyOCD, install the pyOCD Debug Host Tools and make sure they are in your search path.

Common Errors

No connected boards

If you don’t use sudo when invoking pyocd-flashtool, you might get any of the following errors:

No available boards are connected

No connected boards

Error: There is no board connected.

To fix the permission issue, simply add the following udev rule for the NXP LPC1768 interface:

$ echo 'ATTR{idProduct}=="0204", ATTR{idVendor}=="0d28", MODE="0666", GROUP="plugdev"' > /etc/udev/rules.d/50-cmsis-dap.rules

Finally, unplug and plug the board again.

ValueError: The device has no langid

As described by pyOCD issue 259, you might get the ValueError: The device has no langid error when not running pyOCD as root (e.g. sudo).

To fix the above error, add the udev rule shown in the previous section and install a more recent version of pyOCD.

Flashing an Application to 96Boards Nitrogen

Here is an example for the Hello World application. This requires installing the pyOCD Debug Host Tools.

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

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 Nitrogen can be found. For example, under Linux, /dev/ttyACM0. 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

Debugging with GDB

You can debug an application in the usual way. Here is an example for the Hello World application. This also requires pyOCD.

# From the root of the zephyr repository
west build -b 96b_nitrogen samples/hello_world
west debug