ess_matlab_uart

Examples for communicating with an Epson IMU with UART interface

Disclaimer

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This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.

In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to https://unlicense.org

Purpose of this software

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This is demonstration software for evaluation purpose to communicate using Matlab with a supported Epson sensor connected to a serial port on a PC. The user is expected to modify the scripts and extend the functionality to meet their specific evaluation requirements.

Test machine

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• WIN10 Pro 64-bit/PC Core i5-6500 @ 3.2GHz, 16GB RAM
• Matlab R2018a (9.4.0.813654) 64-bit
• Epson M-G32EV041 USB EvalBoard connected to PC USB (USB-UART)
  • Epson IMU M-G3xx & Epson Accel M-A352AD10

Requirements

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• This software is tested on MATLAB R2018a or higher web link
• This is only supported using UART connection to the Epson Sensor web link

Important for UART Interface

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1. This software makes use of Matlab's serial port interface to communicate between the PC and Epson Sensor.

   When connecting to the PC using a USB Serial Port converter, set the BM Latency option to 1 msec.

   Device Manager -> USB Serial Port (COMx) -> Port Settings -> Advanced Change the setting of the Latency Time (msec) in BM Options from 16 (default) to 1

How to use this software

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1. Create a new object using the Epson Sensor model connected on the serial port from within Matlab. Specify the COM port and baudrate (if not 460800) as per your hardware configuration.

   For example:

   >> e = G365Imu('COM12', 460800);
   Issue Software Reset
   Sensor device detected
   Check NOT_READY
   No Errors Detected
   Model: G365PDF0
   Version: 40.19
   Serial#: 00000025
   

   The above will create handle object "e" representing the Epson Sensor connected to the PC serial port interface. A software reset is always asserted to place the Epson Sensor in a known state. Then the model number, version code, and serial number is read from the device.

2. Configure the device's burst output fields by writing a 1 to desired object properties to enable the specific burst fields.

   For IMU Devices

   NOTE: Some IMU fields support 32-bit output which can be set by writing a 2

   Object Property	Description
   Ndflag	Enable NDFLAG field in burst sample, 16-bit only
   TempC	Enable TEMPC field in burst sample 1=16-bit 2=32-bit
   Gyro	Enable or disable Gyro X,Y,Z 1=16bit 2=32-bit
   Accl	Enable or disable Accl X,Y,Z 1=16bit 2=32-bit
   DeltaA	Enable or disable Delta Angle X,Y,Z 1=16bit 2=32-bit
   DeltaV	Enable or disable Delta Velocity X,Y,Z 1=16bit 2=32-bit
   Quaternion	(Only for G330, G366, G365) Enable or disable Quaternion q0,q1,q2, q3 1=16bit 2=32-bit
   Atti	(Only for G330, G366, G365) Enable or disable Attitude ANG1, ANG2, ANG3 1=16bit 2=32-bit
   Gpio	Enable GPIO field in burst sample 16-bit only
   Counter	Enable 16-bit COUNT field in burst sample
   Chksm16	Enable 16-bit CHKSM field in burst sample
   Set16G	* (Only for G330, G366, G370PDG0, G370PDT0) Set accelerometer range 0=8G 1=16G

   For Accelerometer Devices:

   Object Property	Description
   Ndflag	Enable 16-bit NDFLAG field in burst sample
   TempC	Enable 32-bit TEMPC field in burst sample
   Counter	Enable 16-bit COUNT field in burst sample
   Chksm16	Enable 16-bit CHKSM field in burst sample
   TiltX	Enable tilt output on X axis instead of accelerometer by setting to 1
   TiltY	Enable tilt output on Y axis instead of accelerometer by setting to 1
   TiltZ	Enable tilt output on Z axis instead of accelerometer by setting to 1

3. Select the desired output rate & filter setting by setting the object properties.

   For IMU Devices

   Object Property	Description
   DoutRate	2000, 1000, 500, 250, 125, 62.5, 31.25, 15.625, 400, 200, 100, 80, 50, 40, 25, 20
   FilterSel (All IMUs, and for G370PDF1 & G370PDS0 when DoutRate=2000, 400, or 80sps)	tap0, tap2, tap4, tap8, tap16, tap32, tap64, tap128, 32fc50, 32fc100, 32fc200, 32fc400, 64fc50, 64fc100, 64fc200, 64fc400, 128fc50, 128fc100, 128fc200, 128fc400
   FilterSel (Only for G370PDF1 & G370PDS0 when DoutRate is not 2000, 400, or 80sps)	tap0, tap2, tap4, tap8, tap16, tap32, tap64, tap128, 32fc25, 32fc50, 32fc100, 32fc200, 64fc25, 64fc50, 64fc100, 64fc200, 128fc25, 128fc50, 128fc100, 128fc200

   NOTE: Refer to device datasheet for valid combinations of Output Rate vs Filter Selection i.e. For M-G3xx, Table 5.4 Supported Settings For Output Rate and Filter Cutoff Frequency

   For Accelerometer Devices

   Object Property	Description
   DoutRate	1000, 500, 200, 100, 50
   FilterSel	64fc83, 64fc220, 128fc36, 128fc110, 128fc350, 512fc9, 512fc16, 512fc60, 512fc210, 512fc460

   NOTE: Refer to device datasheet for valid combinations of Output Rate vs Filter Selection i.e. For M-A352AD, Table 5.4 Supported Settings For Output Rate and Filter Cutoff Frequency

4. Optionally enable other operating modes

   For IMU Devices

   Object Property	Description
   Gpio2Sel	GPIO2 pin function can be gpio, counter_reset, or external_trigger
   UartAuto	Enable UART_AUTO mode which sends burst sampling data automatically

   NOTE: Register read access is not supported when UartAuto is enabled and device is in SAMPLING mode

   For Accelerometer Devices

   Object Property	Description
   ReducedNoiseEn	Reduce Noise Floor mode
   TempStabEn	Bias stabilization against thermal shock
   ExtEnable	External Trigger mode on falling edge
   UartAuto	Enable UART_AUTO mode which sends burst sampling data automatically

5. To initialize the Epson sensor with current object properties run the setDeviceCfg() method.

   This method should be called after any changes to the object properties to propagate the changes to the sensor device.

>> e.setDeviceCfg;

6. To retrieve scaled sensor data and store it in an array call the getScaledSamples(n) method while specifying the "n" as the number of sensor samples to read.

For example to store 500 samples to the scaleddata structure:

>>scaleddata = e.getScaledSamples(500);

The above command will store the incoming scaled (converted) sensor data into an array while managing the UART interface as follows:

• If not already in SAMPLING, place the device into SAMPLING mode
• If UART_AUTO enabled, send Burst Command
• Burst Read Sensor Data (n samples)
• Post processes the captured sensor data by applying the appropriate scale factors

The default settings unless changed:

For IMU Devices

• Output date rate = 250Hz
• Filter = Moving Average TAP=16
• Burst Output = Ndflag, 16-bit TempC, 16-bit Gyro X,Y,Z, 16-bit Accl X,Y,Z, GPIO, 16-bit Sample Counter
• UartAuto is enabled

For Accelerometer Devices

• Output date rate = 200Hz
• Filter Tap = 512 TAP Fcutoff = 60Hz
• Burst Output = 32-bit TempC, 32-bit ACCL X,Y,Z, 16-bit Sample Counter
• UartAuto is enabled

Precautions For UART Processing Speed

Due variability of the PC processing latency between Matlab, serialport, Epson Sensor, the sensor output rate may be limited.

Data output rate above 500Hz may not be stable on your PC.

If IMU sensor data can not be processed within data output rate timing, DRDY toggling will not be consistent and captured sensor data may have dropped sensor samples. Verify the processing speed/data rate by monitoring the DRDY toggle rate by an oscilloscope probe which should be equal to the specified DoutRate.

Epson UART Device Object Description

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• Object properties must be propagated to the physical device register by calling the setDeviceCfg() method after properties are configured.
• To back propagate device register settings to the object properties call the getDeviceCfg() method

Properties For IMU Devices

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Property	Description
Accl	Enable or disable Accl X,Y,Z 1=16bit 2=32-bit
Atti	(Only for G365, G330, G366) Enable or disable Attitude ANG1, ANG2, ANG3 1=16bit 2=32-bit
BaudRate	Serial Baudrate
BytesPerBurst	Status indicating # of bytes per burst sample
Chksm16	Enable 16-bit CHKSM field in burst sample
ComPort	Serial Port
Counter	Enable 16-bit COUNT field in burst sample
DeltaA	Enable or disable Delta Angle X,Y,Z 1=16bit 2=32-bit
DeltaV	Enable or disable Delta Velocity X,Y,Z 1=16bit 2=32-bit
DoutRate	Output rate in Hz
ExtEnable	Enable External Trigger
FieldsInBurst	Status indicating fields in burst sample
FieldsPerBurst	Status indicating # of fields per burst sample
FilterSel	Filter selection
Gpio	Enable GPIO field in burst sample
Gpio2Sel	GPIO2 pin function can be gpio, counter_reset, or external_trigger
Gyro	Enable or disable Gyro X,Y,Z 1=16bit 2=32-bit
Ndflag	Enable NDFLAG field in burst sample
ProcessSamples	nsamples to buffer for post processing
Quaternion	(Only for G365, G330, G366) Enable or disable Quaternion q0,q1,q2,q3 1=16bit 2=32-bit
Sampling	Status indicating SAMPLING mode
TempC	Enable TEMPC field in burst sample 1=16-bit 2=32-bit
UartAuto	Enable UART_AUTO mode (Register reading not supported when in SAMPLING mode and UART_AUTO is enabled
Set16G	(Only for G330, G366) 0=8G 1=16G accelerometer output range
IsPDC1	(Only for G365) 0=G365PDF1 1=G365PDC1
IsPDCA	(Only for G364) 0=G364PDC0 1=G364PDCA
IsPDS0	(Only for G370PDF1, G370PDS0) 0=G370PDF1 1=G370PDS0
IsPDT0	(Only for G370PDG0, G370PDT0) 0=G370PDG0 1=G370PDT0
ProdId	Detected device Product ID from reading device registers
Version	Detected device Version from reading device registers
SerialId	Detected device Serial Number from reading device registers
ser	Serial object (before Matlab 2020a) or serialport object (Matlab 2020a or later)

Properties For Accelerometer Devices

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Property	Description
BaudRate	Serial Baudrate
BytesPerBurst	Status indicating # of bytes per burst sample
Chksm16	Enable 16-bit CHKSM field in burst sample
ComPort	Serial Port
Counter	Enable 16-bit COUNT field in burst sample
DoutRate	Output rate in Hz
ExtEnable	Enable External Trigger
FieldsInBurst	Status indicating fields in burst sample
FieldsPerBurst	Status indicating # of fields per burst sample
FilterSel	Filter selection
Ndflag	Enable NDFLAG field in burst sample
ProcessSamples	nsamples to buffer for post processing
ReducedNoiseEn	Enable Reduce Noise Floor mode
Sampling	Status indicating SAMPLING mode
TempC	Enable TEMPC field in burst sample
TempStabEn	Enable Bias Stabilization Against Temperature mode
TiltX	Enable Tilt for X-axis in burst sample instead of acceleration
TiltY	Enable Tilt for Y-axis in burst sample instead of acceleration
TiltZ	Enable Tilt for Z-axis in burst sample instead of acceleration
UartAuto	Enable UART_AUTO mode (Register reading not supported when in SAMPLING mode and UART_AUTO is enabled
ProdId	Detected device Product ID from reading device registers
Version	Detected device Version from reading device registers
SerialId	Detected device Serial Number from reading device registers
ser	Serial object (before Matlab 2020a) or serialport object (Matlab 2020a or later)

Object Methods

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• Preferred method to configure the device is by setting the object properties and then calling the setDeviceCfg() method to write properties to the appropriate registers
• However, there are methods to access the device registers directly if needed
• Reading device register values directly by calling readReg() method
• To pass the register address to the readReg(), simply use the object_name.REG_NAME

For example to read MODE_CTRL register REG[0x02(W0)]:

>> e.readReg(e.MODE_CTRL, true);
REG[0x02 (W0)] > 0x0400

• Writing to device register values directly by calling the writeRegH() or writeRegL() methods to write to the HIGH byte or LOW byte respectively.
• NOTE: After writing directly to device registers, run getDeviceCfg() method to synchronize the object properties with current device register settings

For example to write a 0x01 to the HIGH byte of MODE_CTRL register REG[0x02(W0)]:

>> e.writeRegH(e.MODE_CTRL, 1, true);
REG[0x03 (W0)] < 0x01

For example to write a 0x06 to the LOW byte of MSC_CTRL register REG[0x02(W1)]:

>> e.writeRegL(e.MSC_CTRL, 6, true);
REG[0x02 (W1)] < 0x06

Methods For IMU & Accelerometer Devices

Methods	Description
dumpReg	Read back all register values
getDeviceCfg	Update object properties by reading device registers
getModel	Read back MODEL number
getScaledSamples	Call getSampling() and convert data to scaled values
getSerialId	Read back SERIAL_NUM
getVersion	Read back VERSION number
gotoConfig	Go to CONFIG mode
gotoSampling	Go to SAMPLING mode
printTabular	Output a table listing with specified scaled sensor data
readReg	Read a 16-bit value from specified WIN_ID & register address
setDeviceCfg	If not already goto CONFIG mode and program device registers
swResetDevice	Issue SW Reset and wait RESET_DELAY
writeRegH	Write to HIGH byte of specified WIN_ID & register address
writeRegL	Write to LOW byte of specified WIN_ID & register address

Additional Methods For IMU Devices

Methods	Description
testFlash	Sets Flash test bit and waits for bit to clear to check result
testSelf	Sets selftest bit and waits for bit to clear to check result

Additional Methods For Accelerometer Devices

Methods	Description
doSelftests	Perform device self tests (testSENS, testFlash, testACC, testTEMPC, testVDD)

File Listing

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File	Description
EpsonDeviceUart.m	Handle object base class for Epson serial sensor device connected by PC serial port controlled by Matlab
A352Accl.m	Epson A352 Sensor object derived from base class EpsonDeviceUart
G320Imu.m	Epson G320 Sensor object derived from base class EpsonDeviceUart
G330_G366Imu.m	Epson G330PDG0/G366PDG0 Sensor object derived from base class EpsonDeviceUart
G354Imu.m	Epson G354 Sensor object derived from base class EpsonDeviceUart
G364Imu.m	Epson G364PDCA/PDC0 Sensor object derived from base class EpsonDeviceUart
G365Imu.m	Epson G365PDF1/PDC1 Sensor object derived from base class EpsonDeviceUart
G370F_G370SImu.m	Epson G370PDF1/PDS0 Sensor object derived from base class EpsonDeviceUart
G370G_G370TImu.m	Epson G370PDG0/PDT0 Sensor object derived from base class EpsonDeviceUart
exampleEpsonAccl.m	Example matlab script creating Epson Accelerometer serialport object, configure, get sensor samples, print sensor data to console, plot
exampleEpsonImu.m	Example matlab script creating Epson IMU serialport object, configure, get sensor samples, print sensor data to console, plot
createAcclPlot.m	Plot Accl X,Y,Z axes
createGyroPlot.m	Plot Gyro X,Y,Z axes
README.md	This readme file in markdown

Change Record

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Date	Version	Description
2021-08-25	v1.0	Initial release
2023-01-10	v1.01	Minor maintenance, add G330/G366 support, fix deltaV scalefactor G365PDC1, formatting
2023-08-17	v1.02	Minor maintenance, add G370PDG0/G370PDT0 support, minor renaming of IMU properties