SMARTER Polulu-compatible drivers (with sensorless stall and step loss detection)?

Hi, guys,

I'm new to this, so if I say something stupid, please just smile, bear with me and correct me

I know the Pololu-compatible stepper driver breakout boards are open source designs, and that one can create such a board starting from basicly any compatible driver IC.

Why doesn't anybody design such a driver breakout board based on smarter chips, like this one: http://www.onsemi.com/PowerSolutions/product.do?id=AMIS-30623, which come with sensorless stall-detection and step-loss detection? I can imagine a bit higher costs, but nothing close to what such commercial drivers cost (well over the 100$ mark).

I think this kind of driver - or any one based on a smarter chip, that can provide such more advanced functions - would be a BIG winner...

Any ideas?

Other smart IC ideas:

1. The Trinamic TMC246 IC: - A bit pricey, at as low as 8eur/piece, but WAY CHEAPER than their end-products (almost 20x cheaper)

2. The Trinamic TMC249 IC

etc.

you get the idea...

Edited 1 time(s). Last edit at 02/20/2013 05:40AM by erosnicolau.

Hi,
I have obtained the TOS-100 Stepper Driver Shield for Arduino

[www.watterott.com]

to try out the trinamic tmc260 driver. It looks promising. Just need the time to do the firmware integration and to design a board...

Way to go, man!

Pretty shortly I'll have to make my mind about which drivers to use for now on my 3 Megatronics boards:
- classic high current pololu-s
- easydriver - not sure about that one, people say it would be a bit better - adapted with wires to the pololy-type slots
- TOS-100 - adapted with wires to the pololy-type slots (although I need 18 of them and the stock is almost finished on watterott)
- your version of the TOS-100, should this come soon enough

Eros

Hi,

if you need any help or advice with the TOS-100 shields drop me a note. And before you go any Pololu-style adaption way let me know … since doing this based on the shield is very hard (or at least uses a lot of space).
It is also very simple to derrive a breakout board (arbitrary pinout) from the shield just cut it out in EAGLE …

It should be pretty easy to smash together the RAMPS board with some TMC260 drivers … The EAGLE files are hidden inside the Arduino library and Creative Commons …

(If it is not clear yet: I designed the shield & driver)

Hey, @InteractiveMatter,
Great job on the TOS-100! Too bad it's only in classic Arduino format, not in Pololu-standard format too Any plans in that direction too? And too bad your initial run was so small - I noticed they sold like hot cakes! So, congrats, again!

As for myself - I'm no electrician whatsoever, I'm a mere product designer, with general skills in multiple areas, but no specific electronics skills. So all I can do is come up with ideas and questions and rely on the rest of the community for concrete, material products.

And, since I found the "real culprit" , lemme ask you a couple of questions, as you're the most entitled and able to answer them:
1. I know trinamics advertise these ICs as able to do great things, such as sensorless stall detection and step loss - but the guys tell me this is only possible at HIGH RPMs - at least 300-350 RPM. How does the trinamic IC do at detecting stall / step loss when only using VERY small step increments? My application will move a couple of steps at a time, then pause, and so on. Smarter people than me tell me the only way to achieve step-loss/stall detection at such small movement ratios is by means of (expensive!!) encoders...
2. I heard about smarter drivers (and I hold Trinamic's IC in high regard) that are able to drastically reduce the power consumption when using the motors in "hold" mode. I will need to keep a very low power consumption profile, while at the same time keeping the 4 imbalanced robot arms at very precise angles (via reversible 1:100 reductions). My options are to design an output power-off (passive) brake to hold the arms in place while "resting", OR to find drivers capable of greatly reducing the steppers power consumption while "resting" (holding a specific, tense, position). What can you tell me about this trinamic driver, in this regard?

Thank you so much for everything,
Eros