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AVR492: Brushless DC Motor Control usingAT90PWM3

Features BLDC Motor Basics PSC use Hardware Implementation Code Example

Introduction

This application note describes how to implement a brushless DC motor control in

sensor mode using AT90PWM3 AVR microcontroller.

The high performance of AVR core fitted with Power Stage Controller module of

AT90PWM3 enable the design of high speed brushless DC motor applications.

In this document, we give a short description of brushless DC motor theory of opera-

tion, we detail how to control brushless DC motor in sensor mode and also give the

hardware description of ATAVRMC100 reference design used in this application note.

Software implementation is also discussed with software control loop using PID filter.

This application note deals only with BLDC motor control application using Hall effect

position sensors to control commutation sequence.

AVR

Microcontrollers

Application Note

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2 AVR 492 Application Note7518AAVR07/05

Theory of Operation Brushless DC motors are used in a growing number of motor applications as they havemany advantages:

1. They have no brushes so they required little or no maintenance.

2. They generate less acoustic and electrical noise than universal brushed DC

motors.

3. They can be use in hazardous operation environment (with flammable products).4. They have a good weight/size to power ratio...

Such types of motor have a little rotor inertia, the coils are attached to the stator. The

commutation is controlled by electronics. Commutation times are provided either by

position sensors or by coils Back Electromotive Force measuring.

In sensor mode, Brushless DC motor usually consists of three main parts. A Stator, a

Rotor and Hall Sensors.

Stator A basic three phases BLDC motor Stator has three coils. In many motors the number of

coils is replicated to have a smaller torque ripple.

Figure 1 shows the electrical schematic of the stator. It consists of three coils each

including three elements in series, an inductance, a resistance and one back electromo-

tive force.

Figure 1. Stator Electrical Configuration (Three phases, three coils)

Rotor The rotor in a BLDC motor consists of an even number of permanent magnets. The

number of magnetic poles in the rotor also affects the step size and torque ripple of themotor. More poles give smaller steps and less torque ripple. The permanent magnets go

from 1 to 5 pairs of poles. In certain cases it can goes up to 8 pairs of poles.(Figure 2).

L

bemf A

bemf B

bemf C

L,R

L,R L,R
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AVR 492 Application Note

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Figure 2. Three phases, three coil BLDC motor stator and rotor

The coils are stationary while the magnet is rotating. The rotor of the BLDC motor is

lighter than the rotor of a conventional universal DC motor where the coils are placed on

the rotor.

Hall Sensor For estimating the rotor position, three hall sensors are positioned. These hall sensors

are separated by 120 each. With these sensors, 6 different commutations are possible.

Phase commutation depends on hall sensor values.

Power supply to the coils change when hall sensor values change. With right synchro-

nized commutations, the torque remain nearly constant and high.

Figure 3. Hall Sensors signals for CW rotation

Phases Commutation To simplify the explanation of how to operate a three phases BLDC motor a typical

BLDC motor with only three coils is considered. As previously shown, phases commuta-

tion depends on the hall sensor values. When motor coils are correctly supplied, a

magnetic field is created and rotor moves. The most elementary commutation driving

method used for BLDC motors is an on-off scheme: a coil is either conducting or not

conducting. Only two windings are supplied at the same time the third winding is float-

ing. Connecting the coils to the power and neutral bus induces the current flow. This is

referred to as trapezoidal commutation or block commutation.

N S

coils A

coils C

coils B

Rotor

Stator

N

S

coils A

coils C

coils B

Rotor

Stator

N

S

1 pair of poles 2 pairs of poles

t

t

t

Hall_A

Hall_B

Hall_C

t

t

t

Coil_A

Coil_B

Coil_C

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To command brushless DC motors, a power stage made of 3 half bridges is used. Fig-

ure 4 below shows 3 half bridges schematic.

Figure 4. Power Stage

Reading hall sensor value, indicate which switch should be closed.

For motors with multiple poles the electrical rotation does not correspond to a mechani-

cal rotation. A four pole BLDC motor uses four electrical rotation cycles to have one

mechanical rotation.

The strength of the magnetic field determines the force and speed of the motor. By vary-

ing the current flow through the coils the speed and torque of the motor can be adjusted.

The most common way to control the current flow is to control the average current flow

through the coils. PWM(Pulse Width Modulation) is used to adjust the average voltage

and thereby the average current, including the speed. The speed can be adjusted with ahigh frequency from 20 khz to 60 khz.

For a three phase, three coils BLDC motor, the rotating field is described in Figure 5.

Table 1. Switches commutation for CW rotation

Hall Sensors Value (Hall_CBA) Phase Switches

101 A-B SW1 ; SW4

001 A-C SW1 ; SW6

011 B-C SW3 ; SW6

010 B-A SW3 ; SW2110 C-A SW5 ; SW2

100 C-B SW1 ; SW4

CmdSW1

CmdSW2

CmdSW3

CmdSW4

CmdSW5

CmdSW6

VDC

-

+

+DC

C

B

A

0
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Figure 5. Commutation steps and rotating field

Commutation creates a rotating field. Step1 Phase A is connected to the positive DC

bus voltage by SW1 and Phase B is connected to ground by SW4, Phase C is unpow-

ered. Two flux vectors are generated by phase A (red arrow) and phase B (blue arrow)

the sum of the two vectors give the stator flux vector (green arrow). Then the rotor tries

to follow stator flux. As soon as the rotor reach a certain position when the hall sensors

state changes its value from 010 to 011 a new voltage pattern is selected and applied

to the BLDC motor. Then Phase B is unpowered and Phase C is connected to theground. It results in a new stator flux vector Step2.

By following the commutation schematic Figure 3 and Table 1, we obtain six differents

stator flux vectors corresponding to the six commutation steps. The six steps provide

one rotor revolution.

coil A

coil C

coil B

coil A

coil C

coil B

Step1 Step2

coil A

coil C

coil B

coil A

coil C

coil B

Step3 Step4

coil A

coil C

coil B

coil A

coil C

coil B

Step5 Step6

Hall_CBA

011

010

110

100

101

001
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Starter KIT

ATAVRMC100

After this brief theoretical presentation of Brushless DC Motor Control, the practical

implementation will be introduced with the help of an example. The next part of this

application note will deal with the hardware and the software implementation based on

the starter kit ATAVRMC100 running with a microcontroller AT90PWM3.

Electrical schematics are available Figure 21, Figure 22, Figure 23 and Figure 24 at the

end of the document. They describe the reference design for the Starter KitATAVRMC100.

The software includes the control of the speed through a PID corrector. Such a corrector

is composed of three main coefficients : KP, KI, and KD.

KP is the proportionnal gain coefficient, KI is the integral gain coefficient and KD is the

derivative gain coefficient. The error between the desired speed and the real speed

(called error in the Figure 6) is multiplied by each gain. Then, the sum of the three ther-

mes give the command to apply to the motor to get the right speed (Figure 6).

Figure 6. PID diagram

The KP coefficient fixes the motor response time, the KI coefficient is used to cancel the

static error and the KD is used in particular for position regulation(refer to regulation loop

in software description for tuning the coefficients).

++

+

commanderror

PID corrector

desired_speed

real_speed

+-

BLDC Motor

+Power Stage

KI

td

dKD

KP

command t( ) KP e ro r t ( ) K I er r or t ( ) t( )d+ KD tdd

error t ( )+=

error t ( ) desired_sp ee d t( ) _sp ee d t( )real=
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Hardware

Description

As shown in Figure 7 the microcontroller contains 3 Power Stage Controller (PSC).

Each PSC can be seen as a Pulse Width Modulator with two output signals. To avoid

cross conduction a Dead Time control is integrated (see AT90PWM3 datasheet for

more information about PSC orFigure 9 below).

A fault input (Over_Current) is linked to PSCIN. This fault input enables the microcon-

troller to disable all PSC outputs.

Figure 7. Hardware implementation

Its possible to measure the current with two differential amplified channels with pro-

grammable 5, 10, 20 and 40 gain stage. The Shunt resistor has to be adjusted to the

amplifier conversion range.

The Over_Current signal results from an external comparator. The comparators refer-

ence can be adjusted by the internal DAC.The phase commutation has to be done according to hall sensors value. HallA, HallB

and HallC are connected to external interrupt sources or to the three internal compara-

tors. The comparators generate the same type of interrupts as the external interrupts.

Figure 8 shows how the microcontroller I/O ports are used in the starter kit.

AT90PWM3

Motor

Power Bridge

PSCOUT

PSCIN

AMP1+;AMP1-

ACMP0

Over_Current

Current

PSC00PSC10PSC20

PSC01PSC11PSC21

PH_A

PH_B

PH_C

HallAHallBHallC

ACMP1ACMP2

+

Shunt resistor

PSCij : Power Stage Controller i (i = 0,1,2) output j (j = 0,1)ACMPi : Analog Comparator Positive input (i = 0,1,2)AMPi+/- : Analog Differential Amplified channel Positive/Negative inputs (i = 0,1,2)

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Figure 8. Microcontroller I/O Ports use (SO32 package)

VMOT and VMOT_Half are implemented but not used. They can be used to get the

value of the motor supply.

The outputs H_x and L_x are used to control the power bridge. As previously seen, they

depend on the Power Stage Control (PSC) which generate PWM signals. For such

application the recommended mode is the Center Aligned Mode (see Figure 9), the reg-

ister OCR0RA is used to adjust ADC synchronization for current measurement.

Figure 9. PSCn0 & PSCn1 Basic Waveforms in Center Aligned Mode

O p e r a t in g M o d e

P O R T B P IN P o r t F u n c t io n S E N S O RP B 0 / M I S O / P S C O U T 2 0 1 2 H _ C H _ CP B 1 / M O S I / P S C O U T 2 1 1 3 L _ C L _ CP B 2 / A D C 5 / I N T 1 2 0 V M O T V M O TP B 3 / A M P 0 - 2 7 E X T 1

P B 4 / A M P 0 + 2 8 E X T 2P B 5 / A D C 6 / I N T 2 3 0 E X T 5P B 6 / A D C 7 / P S C O U T 1 1 / I C P 1 B 3 1 L _ B L _ BP B 7 / A D C 4 / P S C O U T 0 1 / S C K 3 2 L _ A L _ A

P O R T CP C 0 / I N T 3 / P S C O U T 1 0 2 H _ B H _ BP C 1 / P S C I N 1 / O C 1 B 7 E X T 3P C 2 / T 0 / P S C O U T 2 2 1 0 E X T 4P C 3 / T 1 / P S C O U T 2 3 1 1 L IN _ N S L PP C 4 / A D C 8 / A M P 1 - 2 1 V _ S h u n t - V _ S h u n t -P C 5 / A D C 9 / A M P 1 + 2 2 V _ S h u n t+ V _ S h u n t+P C 6 / A D C 1 0 / A C M P 1 2 6 H a ll B / B E M F _ B H a l lBP C 7 / D 2 A 2 9 D A C _ O U T D A C _ O U T

P O R T DP D 0 / P S C O U T 0 0 / X C K / S S _ A 1 H _ A H _ AP D 1 / P S C I N 0 / C L K O 4 O v e r_ C u r re n t O v e r _ C u r re n tP D 2 / P S C I N 2 / O C 1 A / M I S O _ A 5 M IS O / E X T 1 0P D 3 / T X D / D A L I / O C 0 A / S S / M O S I

_ A6

M O S I / L I N T x D / T x D

/ E X T 7

P D 4 / A D C 1 / R X D / D A L I / I C P 1 A / S CK _ A 1 6 S C K / L IN R x D / R x D/ P O T / E X T 8P D 5 / A D C 2 / A C M P 2 1 7 H a ll C / B E M F _ C H a l lCP D 6 A D C 3 / A C M P M / I N T 0 1 8 V M O T _ H a l f V M O T _ H a l f P D 7 / A C M P 0 1 9 H a l lA / B E M F _ A H a l lA

P O R T EP E 0 / R E S E T / O C D 3 N R E S / E X T 9P E 1 / O C 0 B / X T A L 1 1 4 E X T 6P E 2 / A D C 0 / X T A L 2 1 5 L E D

D e p e n d o n t h e

c o m m u n i c at io n m o d e







OCRnRB

OCRnSBOCRnSA

0

PSCn0

PSCn1

PSC Cycle

On Time 0

On Time 1 On Time 1
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On Time 0 = 2 * OCRnSA * 1/Fclkpsc

On Time 1 = 2* (OCRnRB - OCRnSB + 1) * 1/Fclkpsc

PSC Cycle = 2 * (OCRnRB + 1) * 1/Fclkpsc

The dead time value between PSCn0 and PSCn1 is :

|OCRnSB - OCRnSA| * 1/Fclkpsc

The input clock of PSC is given by CLKPSC. Clock input from I/O clock or from PLL.

Two strategies can be employed for the PWM signals applied on the power stage. The

first consists in applying the PWM signals on the high side AND the low side of the

power bridge and the second in applying the PWM signals only on the high side of the

power bridge.

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Software Description Atmel provides libraries to control Brushless DC motors. The first step is to configureand initialize the microcontroller.

Microcontroller Configuration

and Initialization

The function to be used is named mc_init_motor(). It calls hardware and software initial-

ization functions and initialize all motor parameters (motor direction, motor speed and

stop the motor).

Software Implentation Diagram After microcontroller configuration and initialization, the motor can be started. Only few

functions are needed to control the motor. All user functions are define in mc_lib.h:

void mc_motor_run(void)

Used to start the motor. The regulation loop function is launched to set the duty

cycle. Then the first phases commutation is executed.

Bool mc_motor_is_running(void)

Get the motor state. If TRUE the motor is running. Else if FALSE the motor is

stopped.

void mc_motor_stop(void)

Used to stop the motor.

void mc_set_motor_speed(U8 speed)

Set the user requested speed.

U8 mc_get_motor_speed(void)

Return the current user requested speed.

void mc_set_motor_direction(U8 direction)

Set the motor direction, CW or CCW.

U8 mc_get_motor_direction(void)

Return the current direction of rotation of the motor.

U8 mc_set_motor_measured_speed(U8 measured_speed)

Save the measured speed in the measured_speed variable.

U8 mc_get_motor_measured_speed(void)

Get the measured speed.

void mc_set_Close_Loop(void)

void mc_set_Open_Loop(void)

Set type of regulation Open Loop or Close Loop. See Figure 13 for more

information.

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Figure 10. AT90PWM3 Configuration

mc_init_motor()

mc_init_HW() mc_init_SW()

mc_init_port()

mc_init_pwm()

mc_init_IT()

mc_config-

estimation_speed()

mc_config_samplin

g_time()

Enable_Interrupt()

PSC2_Init()

PSC1_Init()

PSC0_Init()

+ motor direction initialization

+ motor speed initialization

+ Stop the motor

Timer1 configuration

Timer0 configuration

mc_init_comparator0()



mc_init_DAC()

mc_init_ADC()

mc_init_current_measure()

mc_set_Over_Current()

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Figure 11. Software Implentation Diagram.

mc_

switch

_commutation()

m

c_

duty

_cycle()

Set_QxQy()

mc_

hall

_a()

mc_

hall

_b()

mc_

hall

_c()

H_

A

L_

A

H_

B

L_

B

H_

C

L_

C

HallA

HallB

HallC

main()

Software

Ha

rdware

Hardware

mc_set_motor_direction()

mc_motor_stop()

mc_motor_run()

HallA

HallB

HallC

mc_

regulation_

loop()

mc_set_motor_speed()

mc_set_Close_Loop()

mc_set_Open_Loop()

mc_

launch

_sampling_

period()

mc_

estimation_

speed()

ovfl

_timer()

Timer0

Timer1

TIMER0

_OVF

_vect

TIMER1

_COMPA

_vect

all250us

g_

tic

t_timer=8us

TCNT0

ovf_timer

mc_

measured

_speed

mc_

direction

mc

_cmd

_speed

mc_

run_

stop

duty

_cycle

mc_get_motor_direction()

mc_motor_is_runing()

mc_get_motor_direction()

mc_get_motor_speed()

mc_g

et_motor_speed()

mc_

get_duty

_cycle()

mc_set_motor_measured_speed()

mc_get_motor_measured_speed()

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Figure 11 shows four variables mc_run_stop, mc_direction, mc_cmd_speed and

mc_measured_speed. They are the main software variables which can be accessed by

user functions previously described.

The software can be seen as a black box named Motor Control (Figure 12) with inputs (

mc_run_stop, mc_direction, mc_cmd_speed, mc_measured_speed) and output (All

power bridge signals).

Figure 12. Main Software Variables.

Most of the functions are available in mc_drv.h. Only a few depends on the motor type.

Functions can be distributed in four main class : Hardware initialization

void mc_init_HW(void);

All hardware initialization are made in this function. We can found ports initialization,

interrupts initialization, timers and PSCs.

void mc_init_SW(void);

Used to initialized software. Enable all interrupts.

void mc_init_port(void);

Microcontroller I/O ports initialization with DDRx register initialization to choose if

the pin acts as an Output or an Input and PORTx to activate or not the pull-up on

Input.

void mc_init_pwm(void);

This function start the PLL and sets all PSC registers with their initial values.

void mc_init_IT(void);

Modifie this function to enable or disable types of interrupts.

mc_run_stop

mc_direction

mc_cmd_speed

Power Bridge Signals

mc_measured_speed

Motor Control H_A L_AH_B L_BH_C L_C

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void PSC0_Init ( unsignedint dt0,

unsignedint ot0,

unsignedint dt1,

unsignedint ot1);

voidPSC1_Init (

unsigned intdt0,

unsigned int ot0,

unsigned int dt1,

unsigned int ot1);

void PSC2_Init (unsigned int dt0,

unsigned int ot0,

unsigned int dt1,

unsigned int ot1);

PSCx_Init allows the user to select the configuration of the Power Stage Control

(PSC) of the microcontroller.

Phases commutation functions

U8 mc_get_hall(void);

Get the Hall sensors value corresponding to the six commutations steps (HS_001,

HS_010, HS_011, HS_100, HS_101, HS_110).

_interruptvoid mc_hall_a(void);

_interruptvoid mc_hall_b(void);

_interruptvoid mc_hall_c(void);

These functions are executed when an external interrupt is detected (Hall sensor

edge). They allow phases commutation and speed calculation.

void mc_duty_cycle(U8 level);

This function set the PSC duty cycle according to PSC configuration.

void mc_switch_commutation(U8 position);

The phases commutation is done according to hall sensors value and only if the

user start the motor.

Sampling time configuration

void mc_config_sampling_period(void);

Initialize the timer1 to generate an interrupt all 250 us.

_interruptvoid launch_sampling_period(void);

When the 250us interrupt is activated, a flag is set. It can be use for sampling time

control.

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Estimation speed

void mc_config_time_estimation_speed(void);

Configuration of the timer0 to be use for the speed calculation.

void mc_estimation_speed(void);

This function calculate the motor speed with the hall sensor periode measure

principle.

_interruptvoid ovfl_timer(void);

When an overflow occurs on the timer0 a 8bits variable is increased to obtain a

16bits timer with a 8bits timer.

Current measure

_interruptvoid ADC_EOC(void);

As soon as the amplifier conversion is finished, the ADC_EOC function is executed

to set a flag usable for the user.

void mc_init_current_measure(void);

This function initializes the amplifier 1 for the current measure.

U8 mc_get_current(void);

Get the current value if the conversion is finished.

Bool mc_conversion_is_finished(void);

Indicate if the conversion is finished.

void mc_ack_EOC(void);

Reset the End Of Conversion flag.

Over Current detection

void mc_set_Over_Current(U8 Level);

Set the level of detection of an over current. The level is output by the DAC on

external comparator.

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Regulation Loop Two functions select the regulation loop. Open loop or close loop. Figure 13 shows the

regu la t i on l oop imp lemen ted i n t he so f twa re .The two func t i ons a re

mc_set_Close_Loop() and mc_set_Open_Loop().

Figure 13. Regulation Loop

The close loop consists in a speed regulation loop with the PID corrector.

We will further explain how to adjust the coefficients KP and KI. The KD coefficient is

present in the regulation loop but not used.

As previously shown, the KP coefficient is used to regulate the motor response time. In

a first time set KI and KD to 0.Try different value of KP to get a right motor response

time.

If the response time is too slow increase KP gain.

If the response time is quick but unstable decrease KP gain.

Figure 14. Kp tuning

+-

mc_cmd_speed

mc_measured_speed

duty_cycle

PIDMotor

1 : mc_set_Close_Loop() 1 : mc_set_Close_Loop()

2 : mc_set_Open_Loop() 2 : mc_set_Open_Loop()

error

2

11

2

0

20

40

60

80

100

120

140

160

0

0,3

2

0,6

4

0,9

6

1,2

81,6

1,9

2

2,2

4

2,5

6

2,8

83,2

time (s)

SpeedMeasured Kp = 1

Kp = 2

Kp = 3

Kp = 6

Speed ConsignRequested Speed

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KI parameter is used to cancel the static error. Leave the KP coefficient unchanged and

set the KI parameter.

If the error is still different from zero increase KI gain.

If the error is cancelled but after oscillations decrease KI gain.

Figure 15. Ki tuning

In the Figure 14 and Figure 15 example, the right parameters are KP = 1, KI = 0.5 and

KD = 0.

To adjust KD parameter :

If the reponse is still low increase KD gain.

If the reponse is still unstable decrease KD gain.

One another significant point is the sampling time. It has to be chosen according to the

response time of the system. The sampling time must be at least twice smaller than the

response time of the system (according to the Shannon-Nyquist criterie).

Two functions are available for the sampling time configuration (explained previously).

They result in a global variable called g_tick which is set all 250us. With this variable its

possible to configure the sampling time.

CPU & Memory usage All measurements has been realized with Fosc = 8MHz. It also depends on the motor

type too (numbers of pair of poles). With a motor of 5 pair of poles, hall sensor frequencyis five times slower than motor rotation.

All results in Figure 16 are obtained with a three phases BLDC motor with five pairs of

poles and a maximum speed of 14000 rpm.

0

50

100

150

200

250

00,

40,8

1,2

1,6 2

2,4

2,8

3,2

3,6 4

time (s)

SpeedMeasured

Ki=1 ; Kp=1

Ki=2 ; Kp=1

Ki=0,5 ; Kp=1

Speed ConsignRequested Speed
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Figure 16. Microcontroller utilization rate

In the worst case, the microcontroller utilization ratio is about 18% with a sampling time

of 80ms at 14000 rpm.

A first estimation can be made for a faster motor and with a current regulation added.

Activation time for mc_regulation_loop() grows up from 45us to 55us (we have to take

into account the conversion time of the ADC about 7us). For this estimation, a BLDC

motor with a current response time about 2-3ms, five pairs of poles and a maximum

speed of 50000 rpm is chosen.

The maximum speed of the motor is about 50000 rpm, with a rotor of 5 pairs of poles weobtain a Hall sensors frequency of (50000rpm/60)*5 = 4167 Hz. The function

mc_estimation_speed() is launched at each rising edge of hall sensor A, so every 240us

with an activation time of 31us.

For mc_switch_commutation() the three hall sensors have to be considered. The func-

tion is executed at each edges of the three hall sensors (rising edge and falling edge)

we have six interrupts in one Hall sensor period. It results in an activation period of

240/6us = 40us.

Finally, the sampling time of the regulation loop must to be at least twice smaller than

the current reponse time of the motor (about 1ms).

All results are summarized Figure 17.

Figure 17. Microcontroller utilization rate estimated

In such case the utilization ratio of the microcontroller is about 61%.

All ratio measurement have been made with the same software. No communicationmode are used (no UART, no LIN...).

In these conditions, the microcontroller memory usage is :

3175 bytes of CODE memory (Flash occupation = 38.7% ).

285 bytes of DATA memory (SRAM occupation = 55.7%).

Function Parameters activation time activation period Ratio uc %

ovfl_timer() all case 2us 2,05ms 0,1

Speed = 14000 rpm 857,14 us 3,62

Speed = 2800 rpm 4,29 ms 0,72

Speed = 14000 rpm 142,86 us 11,89

Speed = 2800 rpm 714 us 2,38

Open Loop 4,5 us 80 ms 0,0056

Close Loop 45 us 80 ms 0,056mc_regulation_loop()

mc_estimation_speed() 31 us

mc_switch_commutation() 17 us

Function Parameters activation time activation period Ratio uc %

ovfl_timer() all case 2us 2,05 ms 0,1

1 ms

40 us

240 us

5,5

12,91

42,5

mc_regulation_loop()

mc_estimation_speed() 31 us

mc_switch_commutation() 17 us

Speed = 50000 rpm

Speed = 50000 rpm

Close Loop 55 us

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ATAVRMC100

Configuration and

Use

Figure 18 shows us the complet schematics of the various operating mode of the starter

kit ATAVRMC100.

Figure 18. Microcontroller I/O Ports use and communication modes

Operating mode Two differents operating modes are available, set jumpers JP1, JP2 and JP3 according

to Figure 19 to select between both modes. In this application, only Sensor mode is

used. Refer to the ATAVRMC100 User Guide for complete description of hardware.

Operating Mode

PORTB PIN Port Function SENSOR LIN PC Link Switchs/LEDs Debug Wire ISP

PB0/MISO/PSCOUT20 12 H_C H_C H_C H_C H_C H_C H_C

PB1/MOSI/PSCOUT21 13 L_C L_C L_C L_C L_C L_C L_C

PB2/ADC5/INT1 20 VMOT VMOT VMOT VMOT VMOT VMOT VMOT

PB3/AMP0- 27 EXT1 EXT1 EXT1 EXT1 EXT1 EXT1PB4/AMP0+ 28 EXT2 EXT2 EXT2 EXT2 EXT2 EXT2 PB5/ADC6/INT2 30 EXT5 EXT5 EXT5 EXT5 EXT5 EXT5 PB6/ADC7/PSCOUT11/ICP1B 31 L_B L_B L_B L_B L_B L_B L_B

PB7/ADC4/PSCOUT01/SCK 32 L_A L_A L_A L_A L_A L_A L_A

PORTC

PC0/INT3/PSCOUT10 2 H_B H_B H_B H_B H_B H_B H_B

PC1/PSCIN1/OC1B 7 EXT3 EXT3 EXT3 EXT3 EXT3 EXT3 PC2/T0/PSCOUT22 10 EXT4 EXT4 EXT4 EXT4 EXT4 EXT4 PC3/T1/PSCOUT23 11 LIN_NSLP LIN_NSLP LIN_NSLP LIN_NSLP LIN_NSLP LIN_NSLP

PC4/ADC8/AMP1- 21 V_Shunt- V_Shunt- V_Shunt- V_Shunt- V_Shunt- V_Shunt- V_Shunt-PC5/ADC9/AMP1+ 22 V_Shunt+ V_Shunt+ V_Shunt+ V_Shunt+ V_Shunt+ V_Shunt+ V_Shunt+

PC6/ADC10/ACMP1 26 HallB / BEMF_B HallB

PC7/D2A 29 DAC_OUT DAC_OUT DAC_OUT DAC_OUT DAC_OUT DAC_OUT DAC_OUT

PORTD

PD0/PSCOUT00/XCK/SS_A 1 H_A H_A H_A H_A H_A H_A H_A

PD1/PSCIN0/CLKO 4 Over_Current Over_Current Over_Current Over_Current Over_Current Over_Current Over_Current

PD2/PSCIN2/OC1A/MISO_A 5 MISO / EXT10 EXT10 EXT10 EXT10 EXT10 MISO

PD3/TXD/DALI/OC0A/SS/MOSI

_A6

MOSI / LIN TxD / TxD

/ EXT7LIN TxD TxD POT EXT7 MOSI

PD4/ADC1/RXD/DALI/ICP1A/SC

K_A16

SCK / LIN RxD / RxD

/ POT / EXT8LIN RxD RxD EXT8 EXT8 SCK

PD5/ADC2/ACMP2 17 HallC / BEMF_C HallC

PD6ADC3/ACMPM/INT0 18 VMOT_Half VMOT_Half VMOT_Half VMOT_Half VMOT_Half VMOT_Half VMOT_Half

PD7/ACMP0 19 HallA / BEMF_A HallA

PORTE

PE0/RESET/OCD 3 NRES / EXT9 EXT9 EXT9 EXT9 NRES NRES

PE1/OC0B/XTAL1 14 EXT6 EXT6 EXT6 EXT6 EXT6 EXT6

PE2/ADC0/XTAL2 15 LED LED LED LED LED LED

Depend on the

communication mode

Depend on the

communication mode

Depend on the

communication mode

Depend on the

communication mode

Depend on the operating mode



Communication Mode

STK500 JTAGICE mkII

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Figure 19. Sensor mode selection

Figure 19 shows the default jumpers setting to use the software associated with this

application note.

The software delivered with the ATAVRMC100 board allows two operating modes :

No external component, the motor start with a speed of 100%.

One external potentiometer use to adjust the speed of the motor.

Figure 20. Potentiometer connection.

6

4

2

5

3

1

79 10

8

10K

10KP

R

J4: IO-COM

GND

VCC5V

ADC5
http://-/?-http://-/?-

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21


7518AAVR07/05

Conclusion This application note provides a software and hardware solution for sensor brushlessDC motors applications. All source code is available on the Atmel web site.

The software library provides functions to start and control the speed of any sensor

three phases brushless DC motors.

The hardware is based on the minimal design with minimal external components

required for control sensor brushless DC motors.

The AT90PWM3 CPU and memory usage allow a developer to expand his horizons with

new functionalities.

7/28/2019 AVR492

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Figure 21. Schematic page 1/4

5 5

4 4

3 3

2 2

1 1

D

D

C

C

B

B

A

A

PH_

C

BEMF_

C

PH_

B

BEMF_

B

BEMF_

A

PH_

A

PH_

A

PH_

B

PH_

C

BEMF_

C

BEMF_

B

BEMF_

A

Title

Size

D

ocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(ZCDDetecti

on)

4

4

Title

Size

D

ocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(ZCDDetecti

on)

4

4

Title

Size

D

ocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(ZCDDetecti

on)

4

4

A4

Drawn

By:

G

ALLAIN

11

Apr

il

2005

R37

15K

R37

15K

C31

470pF(NotMounted)

C31

470pF(NotMounted)

R4422K

R4422K

C28

100pF

C28

100pF

R33

15K

R33

15K

R3922K

R3922K

C30

100pF

C30

100pF

R35

22K

R35

22K

R38

100K

R38

100K

TP13

BEMF_

ATP13

BEMF_

A

R34

100K

R34

100K

R4022K

R4022K

C29

470pf(NotMounted)

C29

470pf(NotMounted)

C33

470pF(NotMounted)

C33

470pF(NotMounted)

R42

15K

R42

15K

R3622K

R3622K

R4122K

R4122K

C32

100pF

C32

100pF

TP12

BEMF_

BTP12

BEMF_

BTP11

BEMF_

CTP11

BEMF_

C

R43

100K

R43

100K

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23


7518AAVR07/05


5 5

4 4

3 3

2 2

1 1

D

D

C

C

B

B

A

A

VMOT

LIN

EXT8/SCK/LIN_

RxD/RxD/POT

LIN_

NSLP

EXT7/MOSI/LIN_

TxD/TxD

LIN_

NWAKE

VMOT_

Half

VBUS

VBUS_

D

VBUS_

D

VC

C5V

VBUS

VBUS_

D

VBUS_

D

VMOT

VMOT_

Half

EXT8/SCK/LIN_

RxD/RxD/POT

LIN_

NSLP

LIN_

NWAKE

EXT7/MOSI/LIN_

TxD/TxD

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(POWER+LIN)

3

4

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(POWER+LIN)

3

4

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

ATAVRMC1(POWER+LIN)

3

4

POWER

LIN

V

measurement

A4

Drawn

By:

G

ALLAIN

11

Apr

il

2005

C21

10nF

C21

10nF

C23

10uF

C23

10uF

T

P10

G

ND

T

P10

G

ND

R29

10K

R29

10K

R28

100K

R28

100K

1 2 3

J1

LINConnector

J1

LINConnector

VIN

1

GND3

VOUT

2

U6

MC78M05CDT

U6

MC78M05CDT

D5

LL4001

D5

LL4001

C20

100nF

C20

100nF

C24

2.2nF

C24

2.2nF

C18

100nF

C18

100nF

R30

33

R30

33

R32

22K

R32

22K

R27

15K

R27

15K

D6LED_

Green

D6LED_

Green

R26

4.7K

R26

4.7K

INH

8

NWAKE

3

RxD

1

GND

5

TxD

4

LIN

6

BAT

7

NSLP

2

U7

ATA6661

U7

ATA6661

C25

100nF

C25

100nF

C27

100nF

C27

100nF

C19

47uF

C19

47uF

R31

22K

R31

22K

C22

100nF

C22

100nF

C26

220pF

C26

220pF

R2510

R2510

7/28/2019 AVR492

24/26



5 5

4 4

3 3

2 2

1 1

D

D

C

C

B

B

A

A

H_

A

NRES/EXT9

Over_Curre

nt

MISO/EXT1

0

EXT7/MOSI/LIN_

TxD/TxD

EXT3

EXT4

LIN_

NSLP

H_

C

L_

C

EXT8/SCK/LIN_

RxD/RxD/POT

L_

AL_

BDAC_

OUT

EXT2

EXT1

AGND

V_

Shunt+

V_

Shunt-

EXT6

HallC

M

ISO/EXT10

E

XT8/SCK/LIN_

RxD/RxD/POT

EXT7/MOSI/LIN_

TxD/TxD

EXT2

EXT2

EXT6

EXT3

EXT5

EXT7/MOSI/LIN_

TxD/TxD

BEMF_C

HallA

BEMF_A

VMOT_

Half

VMOT

EXT5

EXT8/SCK/LIN_

RxD/R

xD/POT

N

RES/EXT9

EXT1

HallB

BEMF_B

H_AH_BH_CV_S

hunt+

VMO

T_

Half

L_

AL_

BL_

CV_

Shunt-

Over_Current

H_

B

VCC5V

VCC5V

VCC5V

VCC5V

VCC5V

VCC5V

H_

C

H_

A

H_

B

NRES/EXT9

Over_Current

MISO/EXT10

EXT7/MOSI/LIN_

TxD/TxD

EXT3

EXT4

LIN_

NSLP

L_

CEXT6

EXT8/SCK/LIN_

RxD/RxD/POT

MISO/EXT10

EXT8/SCK/LIN_

RxD/RxD/POT

NRES/EXT9

EXT7/MOSI/LIN_

TxD/TxD

EXT3

EXT4

EXT7/MOSI/LIN_

TxD/TxD

EXT2

EXT4

EXT6

EXT8/SCK/LIN_

RxD/RxD/POT

VMOT_

Half

VMOT

V_

Shunt-

V_

Shunt+

EXT1

EXT2

DAC_

OUT

L_

BL_

A

HallC

BEMF_

C

HallA

BEMF_

A

HallB

BEMF_

B

EXT1

EXT5

H_

A

H_

B

H_

C

V_

Shunt+

VMOT_

Half

L

_A

L

_C

L

_B

V

_Shunt-

O

ver_Current

Title

Size

Do

cumentNumber

Rev

Date:

Sheet

o

f

1.6

ATA

VRMC1(MicroController)

1

4

Title

Size

Do

cumentNumber

Rev

Date:

Sheet

o

f

1.6

ATA


1

4

Title

Size

Do

cumentNumber

Rev

Date:

Sheet

o

f

1.6

ATA


1

4

A4

Drawn

By:

G

ALLAIN

11

Apr

il

2005

PD0/PSCOUT00/XCK/SS

_A

1

PC0/INT3/PSCOUT10

2

PE0/RESET/OCD

3

PD1/PSCIN0/CLKO

4

PD2/PSCIN2/OC1A/MISO

_A

5

PD3/TXD/DALI/OC0/SS/MISO

_A

6

PC1/PSCIN1/OC1B

7

VCC

8

GND

9

PC2/T0/PSCOUT22

10

PC3/T1/PSCOUT23

11

PB0/MISO/PSCOUT20

12

PB1/MOSI/PSCOUT21

13

PE1/OCB0/XTAL1

14

PE2/ADC0/XTAL2

15

PD4/ADC1/RXD/DALI/ICP1A/SCK_A

16

PD5/ADC2/ACMP2

17

PD6/ADC3/ACMPM/INT0

18

PD7/ACMP0

19

PB2/ADC5/INT1

20

PC4/ADC8/AMP1M

21

PC5/ADC9/AMP1P

22

AVCC

23

AGND

24

AREF

25

PC6/ADC10/ACMP1

26

PB3/AMP0M

27

PB4/AMP0P

28

PC7/D2A

29

PB5/ADC6/INT2

30

PB6/ADC7/PSCOUT11/ICP1B

31

PB7/ADC4/PSCOUT01/SCK

32

U1

AT90PWM3

U1

AT90PWM3

R110

R110

MISO

1

VCC

2

SCK

3

MOSI

4

RST

5

GND

6

J2

JTAGISP

J2

JTAGISP

C1

100nF

C1

100nF

R45

1K

R45

1K

R46

1K

R46

1K

R471K

R471K

D1

LED_

Green

D1

LED_

Green

R48

10

R48

10

R24.7K

R24.7K

C4

1uF

C4

1uF

R3

100K

R3

100K

C2

100nF

C2

100nF C

3

100nF

C3

100nF

EXT1

1

EXT2

2

EXT3

3

EXT4

4

EXT5

5

EXT6

6

EXT7

7

GND

9

EXT8

8

VCC

10

J4

CON2x5

PORT_

COM

J4

CON2x5

PORT_

COM

1 2 3

JP1

Sel_Sensor_Sensorless_

AJP1


A

1 2 3

JP3


CJP3


C

1 2 3

JP2


BJP2


B

H_

A

1

L_

A

2

H_

B

3

L_

B

4

H_

C

5

L_

C

6

V+

7

Vmot

9

V-

8

OCur

10

J3

STK500_

CON

J3

STK500_

CON

7/28/2019 AVR492

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25


7518AAVR07/05


5 5

4 4

3 3

2 2

1 1

D

D

C

C

B

B

A

A

V_

Shunt-

HS_

C

HS_

B

HS_

A

HallC

HallB

HallA

PH_

C

PH_

B

PH_

A

V_

Shunt+

L_

CH_

B

L_

BH_

A

L_

AH_

C

Over_Current

VBU

S_

D

VBUS_

D

VBUS_

D

VBUS_

D

VCC5V

VCC5V

VCC5V

VBUS_

D

VIR2101

VIR2101

VIR2101

VIR2101

H_

C

L_

CH_

B

L_

BH_

A

L_

A

PH_

C

PH_

B

PH_

A

V_

Shunt+

V_

Shunt-

HallC

HallB

HallA

PH_

A

PH_

B

PH_

C

Over_Current

DAC_

OUT

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

2

4

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

2

4

Title

Size

DocumentNumber

Rev

Date:

Sheet

of

1.6

2

4

ATA

VRMC1(POWERBRIDG

E)

A4

DrawnB

y:

G

ALLAIN

11

Apr

il

2005

TP1

PH_

C

TP1

PH_

C

R12

100

R12

100

C17

100nF

C17

100nF

Q4SUD35N05-26L

Q4SUD35N05-26L

D2BAS21

D2BAS21

R13

100

R13

100

R21

10K

R21

10K

12345678

J5

BLDCCon

J5

BLDCCon

R4

10K

R4

10K

R19

22

R19

22

C7 1

00nF

C7 1

00nF

D3BAS21

D3BAS21

C6

100nF

C6

100nF

C5

100nF

C5

100nF

TP3 HallBTP3 HallB

R22

10K

R22

10K

C12

100nF

C12

100nF

C13

1nF

C13

1nF

TP7

V_

Shunt-

TP7

V_

Shunt-

R18

R_

Shunt

R18

R_

Shunt

R9

10K

R9

10K

D7

SMBJ18(notmounted)

D7

SMBJ18(notmounted)

TP6V_

Shunt+

TP6V_

Shunt+

TP9

PH_

A

TP9

PH_

A

R5 2

2R5 2

2

R84.7K R84.7K

R174.7K

R174.7K

Q1SUD35N05-26L

Q1SUD35N05-26L

Q5SUD35N05-26L

Q5SUD35N05-26L

TP14

Cur_Dtc

TP14

Cur_DtcC111nF C111nF

TP2 HallCTP2 HallC

R74.7K R74.7K

VCC

1

HIN

2

LIN

3

COM

4

LO

5

VS

6

HO

7

VB

8

U2

IR2101S

U2

IR2101S

VCC

1

HIN

2

LIN

3

COM

4

LO

5

VS

6

HO

7

VB

8

U4

IR2101S

U4

IR2101S

Q2SUD35N05-26L

Q2SUD35N05-26L

C101nF C101nF

R2015K

R2015K

TP8

Over_Cur

TP8

Over_Cur

R16

10K

R16

10K

TP5

PH_

B

TP5

PH_

B

R64.7K R64.7K

C14

100nF

C14

100nF

Q3SUD35N05-26L

Q3SUD35N05-26L

C91nF C91nF

R23

22

R23

22

Q6SUD35N05-26L

Q6SUD35N05-26L

VCC

1

HIN

2

LIN

3

COM

4

LO

5

VS

6

HO

7

VB

8

U3

IR2101S

U3

IR2101S

C15

100nF

C15

100nF

R14

10K

R14

10K

C16

10nF

C16

10nF

43

1

5 2

+ -

U5

LMV7219M5

+ -

U5

LMV7219M5

C8

100nF

C8

100nF

TP4HallA

TP4HallA

R10

22

R10

22

R24

22

R24

22

R49

0R49

0

R11

100

R11

100

D4BAS21

D4BAS21R

15

22

R15

22

7/28/2019 AVR492

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Printed on recycled paper.

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