RoadTest: Trinamic Stepper Motor Driver Kit + Motor
Author: Workshopshed
Creation date:
Evaluation Type: Electromechanical
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: There seems to be few direct comarisons for this product. I suspect you would need to combine a simpler stepper motor driver ship such as Allegro's A4988 microstepping bipolar stepper motor driver or TI's DRV8886 2-A Stepper Motor Driver with a motion controller such as Agilient's HCTL-1100. An alternative power component might be something like the Infinion BTN8982
What were the biggest problems encountered?: The biggest problem was the vibration of the motor at high speeds. It wasn't clear what the speed settings on the software represented so picking right the test values was experimental.
Detailed Review:
My plan for the TMC5161-EVAL-KIT by Trinamic is to confirm that the setup can accurately and repeatedly step to the required position. Secondly to look at the setup under stall conditions.
Stepper Motor Driver Kit + Motor - Roadtest Plan
My first step was to get the software installed and do simple test to make the motor turn. The software was easy to install although flashing the development board took quite a few steps, the board needed and extra reboot which was not mentioned in the instructions.
The software automatically detected the board and it is easy to dial in different speed and acceleration profiles. Finding / calculating the correct motor voltage also took a bit of reading and calculation. There seems to be an inconsistency between "nominal coil voltage" and "rated voltage" and no explanation as if to these are the same. The motor produced a fair amount of vibration at higher speeds and it would be interesting to see if one of the other drive modes resolves this.
Stepper Motor Driver Kit + Motor - The hello world of motor testing
The encoder harness needed to be soldered up for this board / motor combination. I found that understanding and using the encoder was challenging and some of the latching / clearing flags descriptions were confusing. There also seemed to be some inconsistencies here between the encoder labelling and the control board labelling. I understand that these might be common terms in the stepper motor industry but it would have been nice for Trinamic to have standardised on one or the other given that all the components are provided by them.
Stepper Motor Driver Kit + Motor - Position Encoder
The test rig was used to demonstrate the ability to return accurately to the same spot. This was done using the TMC5161's inbuilt motion controller configured for different speeds and acceleration.
The chip performed very well at this test and was easy to configure for the different acceleration curves. The test demonstrated that the mechanical aspects of a system need to be factored in when designing accurate systems. Being able to use the IDE to quickly configure and experiment with the acceleration and speed was very useful. Being able to offload the motion to the chip makes writing software for controlling complex electro-mechanical systems so much easier.
Stepper Motor Driver Kit + Motor - Positional Accuracy
There is quite a lot to take in for setting up the stall guard functionality. Firstly the current limits have to be calculated and then threshold for the stall guard. There are a lot of details for this process but they are clearly documented and there is an automated process to help.
The mechanical load can be measured and once the threshold is met the motor locks until reset.
Stepper Motor Driver Kit + Motor - Stall Guard
Compared to the simple motor drivers I've used previously this was significantly more sophisticated. However, the IDE did make configuring and tuning the system straight forward and allowed the parameters and registers to be monitored.
It has good functionality, comprehensive documentation and is easy to use. There are a few inconsistencies in naming in the documentation but nothing that would be a significant issue to an experienced designer.
Prior to running this test, I don't think I would have used such a chip but having worked with it for a few weeks I can see the advantages of this approach. There are few external components required to make a system but there are a few design challenges such as positioning the sense resistors and ensuring sufficient current rating on your PCB and connectors. For those who are not comfortable with that there is a "BOB" Break out board which has these basics in place and you just need to connect it to the MCU and motors.
Since starting the test, I see that the chip is no longer available on the Farnell site and I spotted that there are some comments on the Trinamic website.
This product is not yet in volume production as it will undergo product changes. If you're looking for samples, please contact us directly to discuss the available options.
This could affect your projects if you are planning to design a system so I would get in contact with Trinamic, who are both professional and helpful before starting out with this chip.
