ATAVRMC320 Atmel, ATAVRMC320 Datasheet - Page 4

• Manufacturer Part Number: ATAVRMC320
• Description: KIT EVAL MOTOR CTRL CAN/LIN
• Manufacturer: Atmel
• Series: AVR®r

Specifications of ATAVRMC320

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega32M1
• Primary Attributes: 3-Ph BLDC, Brushed DC, Stepper Motor- Controller Board
• Secondary Attributes: Includes ATAVRMC300 Power Driver Board
• Processor To Be Evaluated: ATmega32M1
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.5 ATmega32M1 Configuration
2.6 Technical Advices
2.6.1 Disconnecting the BLDC Motor
2.6.2 Ground and Power Wirings
3 Firmware
3.1 Main Flow chart
4
AVR172
Line to Line Resistance : 1.8 ohm = R
Back EMF : 3.66 V/Krpm = k_e
Peak current : 5.4A
As Vm=12V, the rated speed will be 2000 rpm.
ATmega32M1 must be programmed to run at 16MHz using PLL (set corresponding
Fuse bits).
The CKDIV8 fuse must be disabled.
Extended/High/Low Fuses configurations are : FF/DF/F3
The BLDC motor must not be disconnected while it is running or while its coils carry
current. It is allowed to disconnect a BLDC motor if the PWM duty cycle is 0% and the
rotor is at rest so that no current is driven through the coils. Be careful, when stopping
the power supply or PWM, a BLDC motor with a high moment of inertia is able to run
for a relatively long time.
One design its own board has to take care of the ground wiring and power wiring. The
power supply of the processor and additional signal conditioning components (e.g.
additional fast comparators, operational amplifiers, …) has to be decoupled from the
motor power supply. The ground connection has to be of low resistance and low
inductance to prevent against voltage drop and noise due to high currents. A ground
plane within a multi layer PCB is recommended for proper operation.
The example firmware is based on the Sensorless method described in AVR928
Application Note.
It is operating in sensorless mode using the ATmega32M1 internal comparators. Hall
sensor wires of the BLDC motor of the kit can remain unconnected.
The source file directory embeds an html documentation which can be opened
through the readme.html file.
The theory of the different tasks has been detailed in AVR928. The application to
ATmega32M1 is detailed in following sections.
The firmware main flowchart is described below :
8306B-AVR-05/10