Mcube MC3635 User manual

MC3635 3-Axis Accelerometer Quick Start Guide and Demo
mCube Proprietary. APS-045-0017v1.1 1 / 17
© 2018 mCube Inc. All rights reserved.
GENERAL DESCRIPTION
The MC3635 is an ultra-low power, low-
noise, integrated digital output 3-axis
accelerometer with a feature set optimized
for wearables and consumer product
motion sensing. Applications include
wearable consumer products, IoT devices,
user interface control, gaming motion input,
electronic compass tilt compensation for
cell phones, game controllers, remote
controls and portable media products.
Low noise and low power are inherent in
the monolithic fabrication approach, where
the MEMS accelerometer is integrated in a
single-chip with the electronics integrated
circuit.
In the MC3635 the internal sample rate can
be set from 14 to 1300 samples / second.
Specific tap or sample acquisition
conditions can trigger an interrupt to a
remote MCU. Alternatively, the device
supports the reading of sample and event
status via polling.
MC3635 FEATURES
Range, Sampling & Power
•±2, 4, 8, 12 or 16g ranges
•8, 10 or 12-bit resolution with FIFO
o14-bit single samples
•Sample rate 14 - 1300 samples/sec
oSample trigger via internal
oscillator, clock pin or software
command
•Sniff and Wake modes
o0.4 μA Sniff current @ 6Hz
oSeparate or combined
sniff/wake
•Ultra-Low Power with 32 sample
FIFO
o0.9 μA typical current @ 25Hz
o1.6 μA typical current @ 50Hz
o2.8 μA typical current @ 100Hz
o36 μA typical current @ 1300Hz
Simple System Integration
•I2C interface, up to 1 MHz
•SPI Interface, up to 8 MHz
•1.6 × 1.6 × 0.94 mm 10-pin
package
•Single-chip 3D silicon MEMS
•Low noise to 2.3mgRMS

MC3635 3-Axis Accelerometer Quick Start Guide and Demo
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© 2018 mCube Inc. All rights reserved.
TABLE OF CONTENTS
1GENERAL OPERATION.................................................................................................. 3
1.1 PINOUTS ............................................................................................................................3
1.2 POWER PINS...................................................................................................................... 3
1.3 I2C PINS.............................................................................................................................. 3
1.4 INTERRUPT PINS...............................................................................................................4
2ASSEMBLY AND TEST................................................................................................... 5
2.1 I2C INTERFACE.................................................................................................................. 5
2.2 SPI INTERFACE..................................................................................................................6
3DEMO.............................................................................................................................. 7
3.1 DOWNLOAD THE DRIVER FROM GITHUB........................................................................ 7
3.2 LOAD THE DEMO ...............................................................................................................7
4LIBRARY REFERENCE ................................................................................................ 10
4.1 CREATE MCUBE_MC3635 OBJECT ................................................................................ 10
4.2 INITIALIZE AND CONFIGURE SENSOR........................................................................... 10
4.3 SET RANGE...................................................................................................................... 10
4.4 READ RANGE ................................................................................................................... 10
4.5 READ RESOLUTION......................................................................................................... 10
4.6 READ RAW COUNT DATA................................................................................................ 10
5DOWNLOADS............................................................................................................... 11
5.1 MC3635 ACCELEROMETER DATASHEET ...................................................................... 11
5.2 EV3635A EVAL BOARD QUICK START GUIDE AND DEMO ........................................... 11
5.3 MC3635 DRIVER AT GITHUB........................................................................................... 11
5.4 ALL OTHER MCUBE DOCUMENTATION......................................................................... 11
6SCHEMATICS............................................................................................................... 12
7BILL OF MATERIALS.................................................................................................... 14
8FABRICATION PRINT................................................................................................... 15
9REVISION HISTORY..................................................................................................... 16
10 LEGAL........................................................................................................................... 17

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
mCube Proprietary. APS-045-0017v1.1 3 / 17
© 2018 mCube Inc. All rights reserved.
1 GENERAL OPERATION
1.1 PINOUTS
1.2 POWER PINS
•DVDD –3.3V Power Supply Input
•GND –Ground Pin for Power and Logic
•R7: The current drawn the sensor can be measured by putting an ammeter in
place of R7.
1.3 I2C PINS
•Connect the SCL (I2C clock pin) to your microcontroller’s I2C clock line.
•Connect the SDA (I2C data pin) to your microcontroller’s I2C data line.

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
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© 2018 mCube Inc. All rights reserved.
R4, R5: If using I2C and I2C pull-up resistors are needed for your application then
install~4.7KΩ resistors into R4 (SCL clock pin) and R5 (SDA data pin) which are not
installed by factory default. In addition, besides soldering resisters on R4/R5, you can add
axial lead 4.7K ohm resistors to the SDA and SCL pin respectively. It will work the same
either way.
NOTE: DO NOT install more than one setup pull-up resistors per I2C bus.
1.4 INTERRUPT PINS
INT - HW interrupt signal pin. It will be driven by the chip when data is ready to read, or a
motion event is detected by the accelerometer. (Not currently supported in the library for
the interrupt pin, so please check the datasheet for the I2C commands toward related
registers).
R6: If using the sensor interrupt signal as open-drain, then install pull-up resistor ~4.7KΩ
into R3 (not installed by default).

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
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2 ASSEMBLY AND TEST
Please note that the SPI and I2C interfaces cannot both be active at the same time as
the clock (SCK) and data (SDA) are shared between the two protocols.
2.1 I2C INTERFACE
The EV3635A evaluation board can be easily wired to any microcontroller. This example
shows a typical Arduino UNO platform. For other microcontrollers, be sure it has I2C with
repeated-start support, then port the code. Please refer to the illustration below to connect the
related pins.
•Connect DVDD to the power supply, 3.3V. (Providing higher voltage, like 5V may
damage the sensor).
•Connect GND to common power/data ground.
•Connect the SCL pin to the I2C clock SCL pin on your Arduino.
•Connect the SDA pin to the I2C data SDA pin on your Arduino.
The MC3635 has a default I2C address of 0x4C and it can be changed to 0x6C by tying
the DOUT pin to VDD.

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
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2.2 SPI INTERFACE
The EV3635A evaluation board can be easily wired to any microcontroller. This example
shows a typical Arduino UNO platform. Please refer to the illustration below for connecting the
related pins and then port the code to get the raw X, Y, Z sensor data.
•Connect DVDD to the power supply, 3.3V. (Providing higher voltage, like 5V may
damage the sensor.)
•Connect GND to common power/data ground.
•Connect SCL to digital I/O pin 13 as Serial Clock.
•Connect SDO to digital I/O pin 12 as Master Input, Slave Output.
•Connect SDA to digital I/O pin 11 as Master Output, Slave Input.
•Connect SCS to digital I/O pin 10 as Slave Select.

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
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© 2018 mCube Inc. All rights reserved.
3 DEMO
3.1 DOWNLOAD THE DRIVER FROM GITHUB
To begin reading sensor data, you will need to download the MC3635_Library from the
github repository. You can do that by visiting the github repository and manually
downloading or simply click this button the attached URL to download the zip file.
https://github.com/mcubemems/Accelerometer_MC3635
Rename the uncompressed folder Accelerometer_MC3635 and check that the
Accelerometer_MC3635 folder contains MC3635.cpp and MC3635.h
Place the Accelerometer_MC3635 library folder to your
Arduino_sketch_folder/libraries/ folder.
You may need to create the library subfolder if it is your first library. Then just restart the
IDE.
An excellent tutorial on Arduino library installation is located at:
http://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use
3.2 LOAD THE DEMO

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
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© 2018 mCube Inc. All rights reserved.
Open up File->Examples->MC3635-> MC3635demo and upload to your Arduino wired up to
the sensor
Now open up the serial terminal window at 9600 baud rate speed to begin the test.

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
mCube Proprietary. APS-045-0017v1.1 9 / 17
© 2018 mCube Inc. All rights reserved.
You will see the output from the serial terminal showing the current range scale and resolution
of the sensor in the first three lines followed by two lines of output sensor data at some output
data rate which depict “raw count" data for line 1: X: -4 Y: 0 Z: 1059 with 8G range, 14bit
ADC resolution.
Line 2 indicates the SI units for measuring acceleration as X:-0.04 m/s^2 Y:0.00 m/s^2 Z:
10.14 m/s^2.

MC3635 3-Axis Accelerometer EV3635A Quick Start Guide and Demo
mCube Proprietary. APS-045-0017v1.1 10 / 17
© 2018 mCube Inc. All rights reserved.
4 LIBRARY REFERENCE
4.1 CREATE MCUBE_MC3635 OBJECT
You can create the MCUBE_MC3635 object with:
MC3635 mc3635_acc = MC3635();
4.2 INITIALIZE AND CONFIGURE SENSOR
Initialize and configure the sensor with:
Mc3635_acc.start();
4.3 SET RANGE
Set the accelerometer max range to ±2g, ±4g, ±8g or ±16g with:
mc3635_acc.SetRangeCtrl(MC3635_RANGE_2G);
mc3635_acc.SetRangeCtrl(MC3635_RANGE_4G);
mc3635_acc.SetRangeCtrl(MC3635_RANGE_8G);
mc3635_acc.SetRangeCtrl(MC3635_RANGE_16G);
4.4 READ RANGE
Read the current range with:
mc3635_acc.GetRangeCtrl();
Returns: 0 for ±2g, | 1 for ±4g, | 2 for ±8g | 3 for ±16g.
4.5 READ RESOLUTION
Read the current resolution with:
mc3635_acc.GetResolutionCtrl();
Returns: 0 for 6-bit | 1 for 7-bit | 2 for 8-bit | 3 for 10-bit | 4 for 12-bit | 5 for 14-bit
4.6 READ RAW COUNT DATA
Read the raw count data and SI unit measurement with:
mc3635_acc.readRawAccel();