TMC428 – Application Note - Trinamic

More documents

Recommendations

Info

TMC428 – Application Note – TMC428 Getting Started – Including StallGuard TM 8 (v. 2.00 / April 14, 2008) 2.2.2 Set the Reference Switch Configuration and the Ramp Mode Both, the reference switch configuration and the ramp mode are configured by access to a single register. Normally, this kind of initialization is done once. The switch configuration ref_conf together with the ramp mode rm has to be chosen. Unused reference switch inputs REF1, REF2, REF3 should be pulled down to ground or disabled by setting ref_conf. Otherwise, the REF1, REEF2, REF3 inputs might detect a switch signal and stop a motor. 2.2.3 Set the Automatic Current Scaling [optional] With the power-on reset settings, the full current is driven when the motor is at rest, during acceleration, and during motion. Automatic down scaling when the motor is at rest reduces power dissipation. This makes sense if the application allows lower holding torque for a motor at rest. For automatic current scaling, it is necessary to switch on the continuous_update, to force the TMC428 to send the current scaling datagram, even if all motors are at rest. That does not cause the TMC428 to sent datagrams to the stepper motor driver chain. 2.4 Running a Motor With all these setting described before, one can simply run a stepper motor. In RAMP_MODE, one just has to write the desired target position into the register x_target of the associated motor. In VELOCITY_MODE, one just has to write the desired target velocity v_target of the associated motor. 3 1 RRS 3 0 2 9 2 8 2 7 ADDRESS 2 6 2 5 Register is_agtat & is_aleat & is_v0 IDX=%1000 (one for each motor) 2 4 RW 2 3 2 2 2 1 Copyright © 2005-2008 TRINAMIC Motion Control GmbH & Co. KG 2 0 1 9 1 8 1 7 1 6 1 5 1 4 1 3 1 2 1 1 DATA 1 0 9 8 7 6 5 4 3 2 1 0 smda 1 0 0 0 is_agtat is_aleat is_v0 a_threshold 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 Figure 4 : Automatic Current Scaling for a Stepper Motor
TMC428 – Application Note – TMC428 Getting Started – Including StallGuard TM 9 (v. 2.00 / April 14, 2008) 2.5 Communication Outline of tmc428demo and Sample428_236 The tmc428demo.exe is a win32 console application. Its communication takes place over a RS232 interface byte by byte. The windows based RS232 communication is used to perform a 32 bit wide SPI communication with the TMC428 on a evaluation kit. For an embedded application running stand alone on a µC, the user just has to write an SPI routine for the µC used for communication between µC an TMC428. For the code example Sample428_236, the SPI routine spi428_uc() for communication with the TMC428 is named Send428(). This has to be completed for a given type of micro controller. The communication is outlined by Figure 5 on page 9. Windows-PC / µC Eval Board Configuration Windows-PC TMC428DEMO main() tmc428spi() spi4win() rs232win32() RS232 µC + TMC428 (e.g. evaluation board) RS232 rs232uc() spi428_uc()* TMC428 *spi428_uc() to be implemented by user (either software SPI or hardware SPI) Figure 5 : Communication Outline for tmc428demo Copyright © 2005-2008 TRINAMIC Motion Control GmbH & Co. KG Stand-Alone µC-TMC428 Configuration Embedded System ( µC + TMC428 ) TMC428DEMO main() tmc428spi() spi428_uc()* TMC428
Page 1 and 2: TMC428 - Application Note - TMC428
Page 7: TMC428 - Application Note - TMC428
Page 19: TMC428 - Application Note - TMC428

TMC428 – Application Note - Trinamic

Create successful ePaper yourself

Delete template?

Save as template?