ATAVRMC100 Hands-on Training

Transcription

1 ATAVRMC100 Hands-on Training (IAR EWAVR Version) ATAVRMC100 Basic Training 1 Version 3_0_0 AVR 12/07/05

2 Introduction This hands-on have been written to help you discover ATAVRMC100 development kit. It is build on four labs. You will find on the ATAVRMC100 training page of the Motor Control CDROM for each lab the complete project source code (IAR) in.zip file. You will also find for each lab, one or several hex file of the solutions. Lab 1 is a first start lab with the starter kit. Lab 2 and Lab 3 are labs where you will have to have a look into the source code to modify it to change the motor behaviour. Lab 4 is a demonstration Lab where you connect ATAVRMC100 to PC through the STK500. ATAVRMC100 Basic Training 2

3 The Objectives of these labs are: ATAVRMC100 Learn to setup the ATAVRMC100 starter kit Learn to download an application code into AT90PWM3 Learn to play with ATAVRMC100 sensor mode demonstration software Important note Each labs are based on the same architecture Overview Subject with all required steps Solution Read carefully all the documentation Requirements ATAVRMC100 Starter kit 12V DC (4A) Power Suppy for the motor STK500 + Power Supply + RS232 cable + ISP 6pins cable + 3 wires PC Windows 2000 or XP RS232 Port or USB to RS232 adapter IAR Version 4.11A or higher AVR Studio Version 4.11 Build 401 or higher ATAVRMC100 Basic Training 3

4 Section 1 Lab Overview The objective of this first lab, it to start ATAVRMC100 starter kit to get the motor running. The AT90PWM3 in the kit is already programmed with a demo code allowing any new users to test the kit in few minutes. 1.2 Subject Unpack the kit and check that all the items are present using the bill of material given with the kit. Then using getting started documentation of the kit, connect the motor as described, also connect the power line. Take care of the polarity of the line before applying the power. Power on the line to get the motor running. (The programmed speed by default is 50.) 1.3 Solution Motor must run now... Welcome in motor control s world...let s go to the second lab ATAVRMC100 Basic Training 4

5 Section 2 Lab Overview The objective of this second lab is to modify the code of the demo to modify the speed of the motor. You will have to use IAR developement environment to edit and compile the code. Then you will need to use AVR studio to program AT90PWM3 with the modified code. 2.2 Subject Unzip the file from the motor control cdrom: \training\atavrmc100\ex2 Launch IAR environment Open the project and identify the function that define the speed of the motor in the main.c file. Modify the speed...(change the value from 15 to 255). Compile the new code. Program the part using ISP connector on STK500 and AVR Studio. ATAVRMC100 Basic Training 5

6 2.3 Solution In the file main.c in the main function locate the function mc_set_motor_speed // Start the motore fun mc_set_motor_speed(50); mc_motor_run(); Change the value from 15 to 255 // Start the motore fun mc_set_motor_speed(15); mc_motor_run(); find in the solution directory (\training\atavrmc100\solution EX2) of the cdrom hex files for different values of speed. Caution : Speed value is an unsigned 8 bit value. ATAVRMC100 Basic Training 6

7 Section 3 Lab Overview The objectif of this third lab is to modify the code of the demo to modify the direction of rotation of the motor. You will have to use IAR developement environment to edit and compile the code. Then you will have to use AVR studio to program AT90PWM3 with the modified code. 3.2 Subject Unzip the file from the motor control cdrom: \training\atavrmc100\ex3 launch IAR environment. Open the project and check what are the actions done in mc_motor_init function. Identify the function that define rotation direction. Use the same function in the main.c. By default rotation direction is clockwise, set it to counterclockwise. Compile the new code. Program the part using ISP connector on STK500 and AVR studio. ATAVRMC100 Basic Training 7

8 3.3 Solution In the file mc_lib.c, the function mc_motor_init can be find: void mc_motor_init() { mc_init_hw(); mc_init_sw(); } mc_motor_stop(); mc_set_motor_direction(cw); mc_set_motor_speed(0); mc_set_motor_measured_speed(0); Use the function mc_set_motor_direction(cw) to modify rotation direction of the motor in main.c void main(void) { // init motor mc_motor_init(); // launch initialization of the motor // Start the motor mc_set_motor_speed(20); mc_set_motor_direction(ccw); mc_motor_run(); while(1) { // Show PSC state according to the Over Current information if(pctl2 & (1<<PRUN2)) switch_off_led();// PSC ON else switch_on_led();//psc OFF => Over_Current // Launch regulation loop // Timer 1 generate an IT (g_tic) all 250us // Sampling period = n * 250us if (g_tic == TRUE) ATAVRMC100 Basic Training 8

9 { g_tic = FALSE; /* This delay is to bypass the inrush current */ if ( over_current_delay!=0) { over_current_delay --; if ( over_current_delay ==0) { mc_set_over_current(100); } } // Get Current and potentiometer value mc_adc_scheduler(); g_regulation_period += 1; if ( g_regulation_period >= 320 ) //n * 250us = Te { g_regulation_period = 0; //mc_set_motor_speed(mc_get_potentiometer_value()); // Set User Speed Command with potentiometer mc_regulation_loop(); // launch regulation loop } } } } ATAVRMC100 Basic Training 9

10 Section 4 Lab Overview The objective of this fourth lab is to use the complete BLDC demo. The complete demo use the uart of the AT90PWM3 to control the motor. On ATAVRMC100 you do not have line drivers to connect uart line directly to your PC. You must use STK500 to interface ATAVRMC100 to your PC. 4.2 Subject Program the AT90PWM3 using ISP connector on STK500 and AVR studio. use the solution Hex file for Lab 4 on ATAVRMC100 training page of from Motor Control CDROM or directly from CD under \training\atavrmc100\solutionex4\pc_uart BLDC_Sensor.a90. Ground of both board must be connected together using a simple wire. (Ground can be connected using ISP connector cable on both boards as already done before for programming) Connect the STK500 to ATAVRMC100 for uart control as described below. Connect RXD and TXD pin of STK500 RS232 SPARE to pin 7 and 8 of I/O Connector of ATAVRMC100.(See connection table and/or pictures below) Table 1: UART Connection Table STK500 TXD RS232 SPARE RXD RS232 SPARE GND ATAVRMC100 Pin 7 of IO Connector (TXD) Pin 8 of IO Connector (RXD) GND ATAVRMC100 Basic Training 10

11 Figure 1. Uart connection from STK500 side Figure 2. Uart connection from ATAVRMC100 side Install PC tools for motor demo from CDROM ATAVRMC100 training menu, or directly double click on the CDROM on : \training\atavrmc100\ex4\mc100- PC\setup.exe Connect PC com port or PC USB-RS232 dongle to DB9 of SPARE RS232 on STK500 (See Figure below). ATAVRMC100 Basic Training 11

12 Figure 3. Complete Demo Connection DB9 to PC Ground Connected using ISP cable RxD / TxD Cable Supply STK500 and ATAVRMC100 board, the motor must run slowly forward Launch on your PC Start\programs\Atavrmc100\Atavrmc100 Enjoy the demo... Note: It is not recommended to unplug the RS232 cable when the program is running on your PC. ATAVRMC100 Basic Training 12

13 4.3 Solution Pc tool able to interact with ATAVRMC100 and motor. You will be able to change the speed of the motor to pre-programmed values, or to ncrease or decrease step by step the motor speed. You can change the motor direction from forward to backward. You can Start and Stop the motor. You can see measured speed compare to speed requested.(in this demo motor is in open loop with no regulation algorithm) When switching motors direction, if overcurrent occurs, it is detected and PC tool allows to restart application. Figure 4. Screen Shoot of PC tools ATAVRMC100 Basic Training 13

14 You can also use Hyperterminal to control the motor. Just configure PC com port at bauds with 8 data bit, 1 stop bit with no parity and no flux control. Table 2: The table below summarize Lab 4 commands. Command Data to Send Data Received Run r Requested speed Stop s None Forward f None Backward b None Speed =15 4 Requested speed Speed =50 0(Zero) Requested speed Speed =100 1 Requested speed Speed =150 2 Requested speed Speed =255 3 Requested speed Speed requested? Requested speed Increment Speed + Requested speed Decrement Speed - Requested speed Speed Measurement m Measured speed Overcurrent Restart i None You can find under \\training\atavrmc100\ex4\quickterm a RS232 tool with above commands already programmed in functions keys. Run Quickterm.exe Read trm file mc100.trm (File->read trm) Change display to hexadecimal (Settings->display->Hexa) Set local echo (Settings->RS232 communications->local Echo) and open the communication (Settings->RS232 communications->connect) Enjoy the demo... ATAVRMC100 Basic Training 14

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16 Section 5 Lab Overview The objective of this fifth lab is to use the complete BLDC demo with speed regulation. This lab uses the same environment than lab 4 for uart and STK500 connexion, please refer to Lab 4 description for board connexion. 5.2 Subject Unzip the file from the motor control cdrom: \training\atavrmc100\ex5 launch IAR environment. Open the project and identify the function that define the regulation mode in main.c (speed regulation mode is already selected). This function must be called after motor_init function. Compile the code. Program the part using ISP connector on STK500 and AVR studio. Connect the STK500 to ATAVRMC100 for uart control as described in Lab 4. Power up STK500 and ATAVRMC100 board, the motor must run slowly forward. Launch on your PC Start\programs\Atavrmc100\Atavrmc100. Set speed to 50, try to brake the motor by squeezing the axis between your fingers to see speed regulation in action. The regulation loop in this demo is optimised for one speed, here it is optimised for Speed=50, so it will not give good results for other speeds. ATAVRMC100 Basic Training 16

17 5.3 Changing the motor Here is a summary of parameters to set in the BLDC demo to have the speed measurement and regulation loop working with every motor. Note: ATAVRMC100 is limited to 50 watt motor (12V 4A). All the configuration is done in the file config_motor.h First you have to calculate K_speed value for speed measurement. K_SPEED = (60 * 255)/(n * t_timer0 * speed_max(rpm)) with n : number of poles pairs. and t_timer0 : 8us speed_max is the maximum speed you will have to measure, in our case this is the maximum speed of the motor, it can be found in every motor documentation For the motor of the kit, the maximum speed is 6200 rpm and 8 pairs of poles it gives K_Speed = ( (60 * 255)/(8 * * 4000) = Verify that the parameters are correctly set for the motor provided in the kit. 5.4 PID Coefficient determination method Here, we will give you the method to determine PID coefficient by measurement method. The method to determine P, I, D is based on measurement, for speed measurement K_speed must be calculated as described above. Kd is always 0. We will need to trace speed=f(t), for that you must mofidy the code to send regulary speed measurement to uart in a text file. Trace Speed=f(time). First set Ki=0, modify Kp to get motor going as close as possible to the requested speed as fast as possible without overshooting. (in reality you will never be able to reach requested speed, you will always have Static Error. Change Ki to minimize the static error, high value of Ki will give you instable system you will have to reach a compromise between precision and stability. ATAVRMC100 Basic Training 17