Silicon Laboratories EFM8SB2-SLSTK2011A User manual

UG238: EFM8SB2-SLSTK2011A User's
Guide
The EFM8SB2-SLSTK2011A is an excellent starting point to get
familiar with the EFM8 EFM8SB2 Sleepy Bee microcontrollers.
The kit contains sensors and peripherals demonstrating some of the MCU's many capa-
bilities. The kit can also serve as a starting point for application development.
The kit includes the following:
KEY FEATURES
• EFM8SB20F64G MCU with 64 KB Flash
and 4 KB RAM.
• 20-pin expansion header.
• Power sources include USB and CR2032
battery.
• 2 user buttons, 1 tri-color LED.
• 8-direction joystick.
• Silicon Labs Si7021 Humidity and
Temperature Sensor.
• 32 kHz crystal for the RTC.
• Ultra low power 128x128 pixel Memory-
LCD.
• EFM8SB2 Sleepy Bee Starter Kit Board
• 1 x CR2032 battery
• Getting Started card
• 1 x mini USB cable
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1. Getting Started
Hardware
To set up the hardware for the EFM8SB2-SLSTK2011A kit:
1. Provide power to the board by connecting the USB connector to the PC using the provided USB cable.
2. Move the switch to the Advanced Energy Monitor (AEM) position.
Figure 1.1. Hardware Setup
Software
The first step to get started with your new EFM8SB2-SLSTK2011A is to go to
http://www.silabs.com/simplicity
The Simplicity Studio software package contains all the tools, drivers, software examples and documentation needed to use the
EFM8SB2 Starter Kit. The board comes pre-loaded with a default application, Clock, to interact with while the software downloads.
After downloading the latest version of Simplicity Studio and installing:
1. Select the J-Link adapter for the kit under [Devices].
2. Click one of the demos available under [Getting Started]>[Demos] or click the [Getting Started]>[Demos]>[View All] to view the
entire list of available demos.
3. Click the [Rainbow Blinky] demo and click [Start] to download and run the demo.
Additional demos showcasing the various features of the EFM8 are also available in Simplicity Studio.
UG238: EFM8SB2-SLSTK2011A User's Guide
Getting Started
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2. Kit Block Diagram
An overview of the EFM8SB2 Starter Kit is shown in the figure below.
ADC
I2C / SMBus
Joystick
EFM8SB2
Microcontroller
GPIO
POWER
Board
Controller
UART
Figure 2.1. EFM8SB2-SLSTK2011A Block Diagram
UG238: EFM8SB2-SLSTK2011A User's Guide
Kit Block Diagram
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3. Kit Hardware Layout
The layout of the EFM8SB2 Starter Kit is shown below.
Kit USB
Connector
CR2032
Battery Holder
Power Source Select
User Push
Buttons User LED
EFM8 Reset Button
EFM8SB2 MCU
Expansion
Header
128x128 Pixel
Memory LCD
Joystick
Humidity and
Temp Sensor
Direct
Debug Connector
Debug IN/OUT
Connector
Reference
Board Connector
Figure 3.1. EFM8SB2-SLSTK2011A Hardware Layout
The EFM8 device on the kit is connected to several peripherals. The table below shows all of the external connections to the MCU.
Table 3.1. Kit MCU Connections
MCU Port Pin Port Pin Assigned
Function
Primary Board Connec-
tion
Secondary Board Con-
nection
Expansion Port Con-
nection (EXP)
P0.0 VREF VREF Caps
P0.1 AGND
P0.2 Port Match Input Push Button 0 (PB0)
P0.3 Port Match Input Push Button 1 (PB1)
P0.4 UART0 TX BC - UART_TX EXP12
P0.5 UART0 RX BC - UART_RX EXP14
P0.6 SMBus0 SDA I2C SDA EXP16
P0.7 SMBus0 SCL I2C SCL EXP15
P1.0 SPI1 SCK DISP - SPI CLK1SPI CLK EXP8
P1.1 SPI1 MISO SPI MISO EXP6
P1.2 SPI1 MOSI DISP - SPI MOSI SPI MOSI EXP4
P1.3 SPI1 NSS SPI CS EXP10
P1.4 GPIO BC - Enable
P1.5 GPIO DISP - SPI CS
P1.6 GPIO EXP3
UG238: EFM8SB2-SLSTK2011A User's Guide
Kit Hardware Layout
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MCU Port Pin Port Pin Assigned
Function
Primary Board Connec-
tion
Secondary Board Con-
nection
Expansion Port Con-
nection (EXP)
P1.7 ADC / CMP Joystick
P2.0 PCA0 CEX0 RGB LED0 EXP5
P2.1 PCA0 CEX1 RGB LED1 EXP7
P2.2 PCA0 CEX2 RGB LED2 EXP9
P2.3 ADC EXP11
P2.4 Timer BC - REFCLK
P2.5 GPIO EXP13
P2.6 GPIO DISP - Enable
P2.7 / C2D GPIO / C2D (for debug) Debug - C2D DISP - Enable
Note:
1. This signal has high loading. If the MCU pin is used for signals where edge speed is critical, this signal should be disconnected
from the pin.
UG238: EFM8SB2-SLSTK2011A User's Guide
Kit Hardware Layout
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4. Power Supply and Reset
4.1 MCU Power Selection
The EFM8SB2 Sleepy Bee MCU on the EFM8SB2-SLSTK2011A is designed to be powered by three different sources:
• Through the on-board debugger.
• By a 3 V Battery.
• An externally supplied power source.
Selecting the power source is done with the slide switch in the lower left corner of the board. The figure shows how the different power
sources can be selected with the slide switch.
AEM
BAT
8
AEM
BAT
Figure 4.1. EFM8SB2-SLSTK2011A Power Switch
With the switch in the AEM position, an on-board low noise LDO with a fixed output voltage of 3.3 V is used to power the MCU. This
LDO is powered from the "J-Link" USB cable.
With the switch in the BAT position, the device may be powered from either a 20 mm coin cell battery (in the CR2032 socket) or an
external power supply (connected to the VMCU and GND pins on the expansion header).
4.2 MCU Reset
The EFM8 MCU can be reset by a few different sources:
• The RESET button.
• An external debugger by pulling the RSTb pin low.
UG238: EFM8SB2-SLSTK2011A User's Guide
Power Supply and Reset
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5. Peripherals
The starter kit has a set of peripherals that showcase some of the features of the EFM8 EFM8SB2 Sleepy Bee microcontroller.
Be aware that most EFM8 I/O routed to peripherals are also routed to the breakout pads. This must be taken into consideration when
using the breakout pads for your application.
5.1 Push Buttons and LEDs
The kit has two user push buttons. They are connected to the EFM8, and are debounced by RC filters with a time constant of 1 ms. The
buttons are connected to pins P0.2 and P0.3.
In addition to the two push buttons, the kit also features a tri-color LED that is controlled by EFM8 GPIO. The LED is connected to pins
P2.0, P2.1, and P2.2 in an active-low configuration.
Figure 5.1. Buttons/LEDs
UG238: EFM8SB2-SLSTK2011A User's Guide
Peripherals
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5.2 Joystick
The kit has an analog joystick with 8 measureable positions. This joystick is connected to the EFM8 on the P1.7 pin and uses different
resistor values to create voltages measurable by the ADC0.
Figure 5.2. Joystick
Table 5.1. Joystick Resistor Combinations
Direction Resistors Combinations (kΩ) Expected UIF_JOYSTICK Voltage (V)1
Center press 0.1
0.1 + 10
0.033
Up (N) 60.4
60.4 + 10
2.831
Up-Right (NE) (N// E)
(N// E) + 10 =21.34 21.34 + 10
2.247
Right (E) 33
33 + 10
2.533
Down-Right (SE) (S// E)
(S// E) + 10 =7.67 7.67 + 10
1.433
Down (S) 10
10 + 10
1.650
Down-Left (SW) (S// W)
(S// W) + 10 =6 6 + 10
1.238
Left (W) 15
15 + 10
1.980
Up-Left (NW) (N// W)
(N// W) + 10 =12.01 12.01 + 10
1.801
Note:
1. These calculated values assume a VMCU of 3.3 V.
UG238: EFM8SB2-SLSTK2011A User's Guide
Peripherals
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5.3 Memory LCD-TFT Display
A 1.28-inch SHARP Memory LCD-TFT has been added to the board to enable interactive applications to be developed. The display has
a high resolution of 128 by 128 pixels and consumes very little power. It is a reflective monochrome display, so each pixel can only be
light or dark, and no backlight is needed in normal daylight conditions.
The display interface consists of an SPI-compatible serial interface and some extra control signals. Data are sent to the display one line
(128 bits) at a time.
The Memory LCD-TFT display is shared with the kit Board Controller, allowing the Board Controller application to display useful infor-
mation when the user application is not using the display. The EFM8 MCU always controls ownership of the display using the
EFM_DISP_ENABLE signal:
• 0: The Board Controller has control of the display.
• 1: The user application (EFM8) has control of the display.
Data are clocked in on EFM_DISP_MOSI (P1.2) when EFM_DISP_CS (P1.5) is high, and the clock is sent on EFM_DISP_SCLK
(P1.0). The maximum supported clock speed is 1 MHz.
Please refer to the display application information for details on driving the display:
http://www.sharpmemorylcd.com/1-28-inch-memory-lcd.html
0: BC controls display
1: EFM controls display
EFM_DISP_ENABLE
8
P1.0 (SPI1)
P1.2 (SPI1)
P1.5 (GPIO)
P2.6 (GPIO)
Figure 5.3. 128x128 Pixel Memory LCD
5.4 Humidity and Temperature Sensor
The EFM8SB2-SLSTK2011A board includes a Silicon Labs Si7021 humidity and temperature sensor to enable datalogging applica-
tions. The EFM8 MCU communicates with this sensor over the I2C / SMBus hardware interface.
Figure 5.4. Humidity and Temperature Sensor
UG238: EFM8SB2-SLSTK2011A User's Guide
Peripherals
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5.5 32 kHz Crystal
The kit has a 32 kHz crystal connected to the RTC crystal pins on the EFM8 MCU. This crystal enables the low power modes on the
MCU that utilize the RTC.
Figure 5.5. 32 kHz Crystal
UG238: EFM8SB2-SLSTK2011A User's Guide
Peripherals
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