Ebyte E180-ZG120B-TB Test Board

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When using this board with RIOT, set the BOARD variable to e180-zg120b-tb in your Makefile. If you follow the standard RIOT project structure, your Makefile should look like this:

# name of your application
APPLICATION = hello-world

# Change this to your board if you want to build for a different board
BOARD ?= e180-zg120b-tb

# This has to be the absolute path to the RIOT base directory:
RIOTBASE ?= $(CURDIR)/RIOT

include $(RIOTBASE)/Makefile.include

Support for Ebyte E180-ZG120B-TB Test Board

Overview

Image of the E180-ZG120B test board

Ebyte E180-ZG120B Test Board is equipped with the EFM32 microcontroller. It is specifically designed for low-power applications, having energy-saving peripherals, different energy modes and short wake-up times.

Hardware

MCU

MCU	EFR32MG1B232F256GM32
Family	ARM Cortex-M4F
Vendor	Ebyte
Vendor Family	EFM32 Mighty Gecko 1B
RAM	32.0 KiB (1.0 KiB reserved by radio blob)
Flash	256.0 KiB
EEPROM	no
Frequency	up to 38.4 MHz
FPU	yes
MPU	yes
DMA	8 channels
Timers	2x 16-bit + 1x 16-bit (low power)
ADCs	12-bit ADC
UARTs	2x USART, 1x LEUART
SPIs	2x USART
I2Cs	1x
Vcc	1.85 V - 3.8 V
Datasheet	Datasheet
Manual	Manual
Board Manual	Board Manual

Pin Mapping

Warning: At least for revision 10199-V1.0 of the test board most of the silkscreen labels are incorrect.

Note: Everything here assumes the board is oriented so that the USB connector is on the top.

Right Header

(Top-left pin is 1, top-right pin is 2, and so on.)

Description	Pin (left)	Pin (right)	Description
GND	1	2	VCC
PB13	3	4	PB12
PB11	5	6	PD15
NC (pin 8 on E180-ZG120B)	7	8	NC (pin 7 on E180-ZG120B)
PA1	9	10	PA0
PD14	11	12	PD13
GND	13	14	GND

(Leftmost pin is 1, second from left is 2, and so on.)

Description	Pin (left to right)
NC (pin 23 on E180-ZG120B)	1
NC (pin 22 on E180-ZG120B)	2
PC11	3
NC (pin 20 on E180-ZG120B)	4
PF2	5
PC10	6
NC (pin 17 on E180-ZG120B)	7
NC (pin 16 on E180-ZG120B)	8
NC (pin 16 on E180-ZG120B)	9

Left Header

(Top-left pin is 1, top-right pin is 2, and so on.)

Description	Pin (left)	Pin (right)	Description
NC (pin 24 on E180-ZG120B)	1	2	SWCLK
SWDIO	3	4	PB14
PB15	5	6	NC (pin 29 on E180-ZG120B)
PF3	7	8	NC (pin 31 on E180-ZG120B)
NC (pin 32 on E180-ZG120)	9	10	NC (pin 33 on E180-ZG120B)
NC (pin 34 on E180-ZG120)	11	12	NC (pin 35 on E180-ZG120B)
GND	13	14	Reset

Peripheral mapping

Peripheral	Number	Hardware	Pins	Comments
ADC	0	ADC0	CHAN0: internal temperature	Ports are fixed, 14/16-bit resolution not supported
HWCRYPTO	—	—		AES128/AES256, SHA1, SHA256
RTT	—	RTCC		1 Hz interval. Either RTT or RTC (see below)
RTC	—	RTCC		1 Hz interval. Either RTC or RTT (see below)
Timer	0	TIMER0 + TIMER1		TIMER0 is used as prescaler (must be adjacent)
	1	LETIMER0
UART	0	USART0	RX: PA1, TX: PA0	Default STDIO output

User interface

Peripheral	Mapped to	Pin	Comments
Button	PB0_PIN	PD15	Mode Change
	PB1_PIN	PD13	Touch Link
	PB2_PIN	PB11	Baud Rate Reset
LED	LED0_PIN	PF2	GPIO2 LED
	LED1_PIN	PF3	Link LED

The fourth button with the Chinese description is the reset button.

Implementation Status

Device	ID	Supported	Comments
MCU	EFR32MG1B	yes	Power modes supported
Low-level driver	ADC	yes
	Flash	yes
	GPIO	yes	Interrupts are shared across pins (see reference manual)
	HW Crypto	yes
	I2C	yes
	PWM	yes
	RTCC	yes	As RTT or RTC
	SPI	partially	Only master mode
	Timer	yes
	UART	yes	USART is shared with SPI. LEUART baud rate limited (see below)
	USB	no

Board configuration

Clock selection

There are several clock sources that are available for the different peripherals. You are advised to read AN0004.0 to get familiar with the different clocks.

Source	Internal	Speed	Comments
HFRCO	Yes	19 MHz	Enabled during startup, changeable
HFXO	No	38.4 MHz
LFRCO	Yes	32.768 kHz
LFXO	No	32.768 kHz
ULFRCO	No	1 kHz	Not very reliable as a time source

The sources can be used to clock following branches:

Branch	Sources	Comments
HF	HFRCO, HFXO	Core, peripherals
LFA	LFRCO, LFXO	Low-power timers
LFB	LFRCO, LFXO, CORELEDIV2	Low-power UART
LFE	LFRCO, LFXO	Real-time Clock and Calendar

CORELEDIV2 is a source that depends on the clock source that powers the core. It is divided by 2 or 4 to not exceed maximum clock frequencies (EMLIB takes care of this).

The frequencies mentioned in the tables above are specific for this starter kit.

It is important that the clock speeds are known to the code, for proper calculations of speeds and baud rates. If the HFXO or LFXO are different from the speeds above, ensure to pass EFM32_HFXO_FREQ=freq_in_hz and EFM32_LFXO_FREQ=freq_in_hz to your compiler.

You can override the branch’s clock source by adding CLOCK_LFA=source to your compiler defines, e.g. CLOCK_LFA=cmuSelect_LFRCO.

Low-power peripherals

The low-power UART is capable of providing an UART peripheral using a low-speed clock. When the LFB clock source is the LFRCO or LFXO, it can still be used in EM2. However, this limits the baud rate to 9600 baud. If a higher baud rate is desired, set the clock source to CORELEDIV2.

Note: peripheral mappings in your board definitions will not be affected by this setting. Ensure you do not refer to any low-power peripherals.

RTC or RTT

RIOT-OS has support for Real-Time Tickers and Real-Time Clocks.

However, this board MCU family has support for a 32-bit Real-Time Clock and Calendar, which can be configured in ticker mode or calendar mode. Therefore, only one of both peripherals can be enabled at the same time.

Configured at 1 Hz interval, the RTCC will overflow each 136 years.

Hardware crypto

This MCU is equipped with a hardware-accelerated crypto peripheral that can speed up AES128, AES256, SHA1, SHA256 and several other cryptographic computations.

A peripheral driver interface is proposed, but not yet implemented.

Usage of EMLIB

This port makes uses of EMLIB by Ebyte to abstract peripheral registers. While some overhead is to be expected, it ensures proper setup of devices, provides chip errata and simplifies development. The exact overhead depends on the application and peripheral usage, but the largest overhead is expected during peripheral setup. A lot of read/write/get/set methods are implemented as inline methods or macros (which have no overhead).

Another advantage of EMLIB are the included assertions. These assertions ensure that peripherals are used properly. To enable this, pass DEBUG_EFM to your compiler.

Pin locations

The EFM32 platform supports peripherals to be mapped to different pins (predefined locations). The definitions in periph_conf.h mostly consist of a location number and the actual pins. The actual pins are required to configure the pins via GPIO driver, while the location is used to map the peripheral to these pins.

In other words, these definitions must match. Refer to the data sheet for more information.

This MCU has extended pin mapping support. Each pin of a peripheral can be connected separately to one of the predefined pins for that peripheral.

Flashing the device

The board has no integrated programmer/debugger and no bootloader. Hence, an external SWD programmer/debugger such as the SEGGER JLink or the ST-Link is required. Connect at least the SWDIO, SWCLK, and GND to the programmer. If JLinkExe is found in $PATH, jlink is used by default for flashing, otherwise openocd is the default. When using OpenOCD, the stlink is the default for OPENOCD_DEBUG_ADAPTER; provide a different value if you use other hardware.

Note: When flashing with OpenOCD, leave the NRESET pin unconnected. The configuration does a soft reset only to work around an issue attaching with the hardware reset signal.

Flashing is supported by RIOT-OS using the command below:

make flash

To run the GDB debugger, use the command:

make debug

Or, to connect with your own debugger:

make debug-server

Some boards have (limited) support for emulation, which can be started with:

make emulate

Supported Toolchains

For using the Ebyte E180-ZG120B-TB starter kit we strongly recommend the usage of the GNU Tools for ARM Embedded Processors toolchain.

License information

Ebyte’ EMLIB: zlib-style license (permits distribution of source).