ST UM2711 User manual

Introduction
The STSW-ROBOT-1 firmware example for the EVALKIT-ROBOT-1 evaluation kit offers a ready-to-use brushless servomotor
solution consisting of the STSPIN32F0A control board and a maxon EC-i 40 brushless DC motor.
Figure 1. EVALKIT-ROBOT-1
Getting started with the STSW-ROBOT-1
UM2711
User manual
UM2711 - Rev 1 - April 2020
For further information contact your local STMicroelectronics sales office.
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1Hardware and software requirements
The STSW-ROBOT-1 requirements are the following:
• One EVALKIT-ROBOT-1
• A 36 V / 120 W DC power supply(1)
• An RS485 2-wires serial port
• A communication software package based on MODBUS protocol
• One of the supported development toolchains:
– IAR Embedded Workbench for ARM,
– Keil microcontroller development kit
– STM32CubeIDE.
• An SWD programmer/debugger supporting the STM32F0 family, such as the STLINK-V3 from
STMicroelectronics.
1. The operating range of the control electronics is between 12 V and 45 V. However, the system provides best performance
with a supply voltage of 36 V ±20 %
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Hardware and software requirements
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2Getting started
This firmware example is based on the MCSDK implementing high performance PMSM FOC control with
positioning features. The application firmware interfaces with the middleware via the specific API (MC_API).
The MODBUS RTU communication is based on the FreeModbus library and the application firmware interfaces
with the middleware via the specific API (MB_API).
Peripheral management is performed by the STM32Cube low level divers (LL) and Hardware Abstraction Layer
(HAL) based on the standard CMSIS library.
Figure 2. Firmware architecture
2.1 Folders structure
This section provides an overview of the package contents:
• MotorControl Workbench project
•Binary folder containing the compiled binary file
•EVALKIT_ROBOT_1_SDK543_Positioning_LL folder containing the source code, the CobeMX project file
and the toolchains’ projects
The source code sub-folder structure is the following:
•Drivers: STM32 HAL and LL libraries and CMSIS drivers
•MCSDK_v5.4.3: Motor control Field Oriented Control middleware
•modbus: MODBUS communication middleware
•Inc: Application include files
•Src: Application source files
•EWARM: IAR Embedded Workbench V8 project
•MDK-ARM: Keil-ARM uVision V5 project
2.2 Main application code
The main application consists of the following sections:
1. Initialization: Peripherals are configured and data structures are initialized
2. Encoder alignment: Mechanical alignment procedure is executed
3. Main loop: Infinite loop monitoring command request, execution and faults
4. Motor control loop (interrupt based): executes the PMSM FOC algorithm (part of MCSDK)
5. MODBUS loop (interrupt based): manages the MODBUS RTU communication
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2.3 MC_API
The Motor Control API (Src\mc_api.c) are part of the Motor Control SDK and provides the key functions
controlling the motor.
The functions listed below are used by the firmware example, for more details regarding Motor Control SDK API,
refer to the relevant User Manual.
•MC_StartMotor1: Initiates the start-up procedure for the motor including the encoder alignment
•MC_StopMotor1: Initiates the stop procedure for the motor
•MC_ProgramPositionCommandMotor1: Programs the execution of a position command indicating the
target mechanical position (fTargetPosition) in radian and the expected execution time (fDuration) in seconds
•MC_GetControlPositionStatusMotor1: Returns the status of the positioning control state machine
•MC_GetAlignmentStatusMotor1: Returns the status of the encoder alignment (start-up sequence)
•MC_GetOccurredFaultsMotor1: Returns a bitfield showing the new faults detected by the motor control
algorithm
•MC_AcknowledgeFaultMotor1: Acknowledge a Motor Control fault occurred during motor control enabling
a new command execution
2.4 MB_API
The MODBUS RTU API (modbus\mb_API.c) manages the direct inputs, coils and holding registers of the
application.
•setMovementCompleted: Sets the DONE direct input high or low
•setZeroReached: Sets the ALIGN direct input high or low
•getTargetPos_Deg: Returns the target position in degrees stored in holding registers
•getMovementDuration_s: Returns the target movement duration (seconds) according to the value in the
holding registers (milliseconds)
•getNewCommand: Returns true if MOVE coil is high
•clearCommand: Forces MOVE coil low
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MC_API
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3Customization
The firmware default configuration can be modified using the MotorControl Workbench and the STM32CubeMX
software.
3.1 MODBUS section customization
The MODBUS section (i.e., slave address, coils, direct inputs, holding registers, etc.) can be customized by
modifying the following code files:
• mb_API.c/.h: API interfacing the MODBUS with application level
• mbtask.c/.h: Implementation of the callbacks managing:
– Holding registers read/write
– Input registers read
– Coils read/write
– Discrete inputs read
The following table provides the parameters defining the MODBUS data model and slave address:
Table 1. MODBUS configuration parameters
Parameter Location Description
MB_SLAVE_ADDRESS mbtask.h Set the slave address of the device
REG_INPUT_START mbtask.h Input registers starting counter
REG_INPUT_NREGS mbtask.h Number of input registers (bytes)
REG_HOLDING_START mbtask.h Holding registers starting counter
REG_HOLDING_NREGS mbtask.h Number of holding registers (bytes)
REG_COILS_START mbtask.h Coils starting counter
REG_COILS_SIZE mbtask.h Number of coils (bits)
REG_DISC_START mbtask.h Discrete inputs starting counter
REG_DISC_SIZE mbtask.h Number of discrete inputs (bits)
MB_FUNC_OTHER_REP_SLAVEID_ENABLED mbconfig.h Enable/Disable Report Slave ID function
MB_FUNC_READ_INPUT_ENABLED mbconfig.h Enable/Disable read input register function
MB_FUNC_READ_HOLDING_ENABLED mbconfig.h Enable/Disable read holding register function
MB_FUNC_WRITE_HOLDING_ENABLED mbconfig.h Enable/Disable write holding register function
MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED mbconfig.h Enable/Disable write multiple holding register function
MB_FUNC_READ_COILS_ENABLED mbconfig.h Enable/Disable read coils function
MB_FUNC_WRITE_COIL_ENABLED mbconfig.h Enable/Disable write coils function
MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED mbconfig.h Enable/Disable write multiple coils function
MB_FUNC_READ_DISCRETE_INPUTS_ENABLED mbconfig.h Enable/Disable read discrete inputs function
MB_FUNC_READWRITE_HOLDING_ENABLED mbconfig.h Enable/Disable read/write holding register function
3.2 Starting from MotorControl Workbench project
The package contains the MotorControl Workbench project used for code generation. Using this project, it is
possible to modify all the configurations related to the control algorithm and related peripherals.
Note: The communication protocol included in the MCSDK does not support RS485 implemented in the EVALKIT-
ROBOT-1 board.
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Customization
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After the configuration changes, follow the steps in the procedure below:
Step 1. Click on “Generate Code” button.
Step 2. Select your target toolchain and check the LL library option.
Step 3. According to the changes, you have two options:
– No changes to the peripheral setup: use the “UPDATE” function. This option does not overwrite
the STM32CubeMX project. You can immediately open the output project for the target toolchain
and jump to step 4 in Section 3.3 .
– Some changes on the peripheral setup or a complete clean-up of the project is needed: use the
“GENERATE” function and follow the steps below.
Step 4. After the code generation is completed, click on “Run STM32CubeMX”.
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Step 5. The automatically generated STM32CubeMX project miss some peripheral configurations. The
following changes must be done:
Step 5a. Reset configuration for PB0 (Reset_State option in drop-down list)
Step 5b. Configure PF1 as GPIO_EXTI1 and label it “M1_ENCODER_Z”
Step 5c. Configure PA15 as GPIO_Output and label it “RS485_DE”
Step 5d. Configure PF0 as GPIO_Output and label it “LED”
Step 5e. Configure the USART1 for asynchronous operation and map TX/RX to PB6/PB7 GPIOs. No
hardware flow control is required.
Details about configuration of the UART are shown in the following figures.
Figure 3. UART configuration panel (basic)
Figure 4. UART configuration panel (advanced)
Step 5f. Configure one of the available timers as PWM no output for the MODBUS RTU timeout
management (by default TIM14).
It must be set in order to increment at a 50 μs rate (PSC = 2399 for 48 MHz clock).
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Figure 5. TIM14 configuration panel
Step 5g. Configure one of the available timers as PWM no output for the MODBUS execution
scheduler (by default TIM16).
It must be set in order to increment at 1 μs rate (PSC = 47 for 48 MHz clock) and with a
period of 2 ms (ARR = 1999).
Figure 6. TIM16 configuration panel
Step 5h. Enable interrupts for USART (priority 3) and timers (priority 2).
From the code generation point of view, select sequence ordering, IRQ handler generation
and HAL_Handler call for the timers. For the USART only, select sequence ordering and
IRQ handler generation.
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Figure 7. NVIC configuration panel
Figure 8. NVIC configuration panel (code generation)
Step 6. Select your target toolchain and check other options in the “Project Manager” tab.
Step 7. Click on “Generate Code” button.
Step 8. After the code generation is completed, click on “open project”.
Step 9. Open the stm32f0xx_it.c file and modify the empty interrupt handlers.
Step 10. Modify the IRQ_Handler of the MODBUS RTU Timeout timer as shown below:
Figure 9. MODBUS RTU timeout IRQ handler
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Step 11. Modify the IRQ_Handler of the MODBUS scheduler timer as shown below:
Figure 10. MODBUS scheduler timer IRQ handler
Step 12. Modify the IRQ_Handler of the UART interface as shown below:
Figure 11. UART IRQ handler
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