What's the current (ha!) favorite stepper motor driver chip?

Pongo

Pongo

Senior Member
I have a small stepper on the way from China, it's a NEMA 17 and max current is 1.8 amps or less. I think I would like to have the picaxe just control direction and stop/go. It's a long time since I've played with steppers and was thinking of getting one of these DRV8825 boards.

Does anyone have an opinion or alternate suggestions to share?
 
neiltechspec

neiltechspec

Senior Member
I think you might be better with an L298N based board. That one you linked to doesn't look up to the job to me.

I have 2 NEMA 17 equivalent running on a couple of these L298N's driven by 14M2's.

Neil
 
O

oracacle

Senior Member
I used a THB 6064 driver board from mass mind.
it has 8 micro step options and can drive upto 4.5A peak (4 continuous iirc).
What driver you use will mostly depend what you are doing with t
 
rq3

rq3

Senior Member
Pongo said:
I have a small stepper on the way from China, it's a NEMA 17 and max current is 1.8 amps or less. I think I would like to have the picaxe just control direction and stop/go. It's a long time since I've played with steppers and was thinking of getting one of these DRV8825 boards.

Does anyone have an opinion or alternate suggestions to share?
Click to expand...
I love the Texas Instruments DRV8825. It allows very complete control of the stepper, including winding decay and micro-stepping. It is also very good at protecting itself against over-current, temperature, etc. It's main drawback is that it is a very small surface mount device, and has to be reflowed to a multi-layer board for adequate heatsinking. In the attached photo, the 8825 is the small chip in the center of the board, and you can see a 20M2 Picaxe next to it for scale. The board also includes voltage regulation, the programming circuit, and a Freescale digital barometer. The gold pins connect to a color OLED display and 4 touch switches (Picaxe driven).

DRV8825.jpg
 
Pongo

Pongo

Senior Member
Thanks for the inputs. The L298N was my favorite before I decided I wanted a more complete solution, which would mean adding a 297 chip. Those mass mind boards look great but are not in the budget for my prototype :( I think I will go with the DRV8825 since as rq3 writes it's a very complete solution - but I'll be sure to add a bigger heatsink :)
 
marzan

marzan

Senior Member
@Pongo, those boards are used for 3d printers. There are many variations of the same thing but the pinouts are always the same. they have pins for power, gnd, step, dir, and the other pins are for jumper settings for 1/2, 1/4, 1/8, 1/16th stepping. I have these in my printer. all of them are good as long as you don`t overwork them. I have been using them 12 hours a day for months without an issue. Believe it or not you can get even cheaper ones from china ! for nema 17 they are good. I used to use Geckodrives, but at over $100 each, I now use the ones you described for nema 17`s.
OT for a moment, they now have a great little PCB maker as a complete project that looks really good. it uses the 3d printer setup but modified to be a pcb mill. If anyone wants to check it out, look up "cyclone PCB". It`s open source, and if anyone in oz wants to make one, I can make up the parts. I would make one myself, but too many other projects to finish first.
Marz.
 
Pongo

Pongo

Senior Member
Thanks for that Marz. It's a very light duty application, the motor will only rotate a shutter disk +/- 45 degrees maybe once a second so I've gone ahead and ordered the board.
 
Pongo

Pongo

Senior Member
Update: The DRV8825 board arrived and drives the motor very nicely. The motor turned out to be < 2 ohms per winding and needs something over 1 amp so a pwm solution was the way to go. H Bridge drivers don't work at low voltages so using an L298, which requires 7 volts min, without pwm would mean wasting a lot of power in resistors. I'm running the board from 8.5 volts (min is 8.2) and the chip doesn't get hot unless I really wind the current up - which is easy to do by accident because the current trimpot a) works backwards, and b) it doesn't have a rotation stop. All things considered it was a good deal for only $6.
 
D

der_fisherman

Member
Allegro Stepper Chips

It seems you are sorted, but there appears to be no mention of the Allegro chips, that have some remarkable features insofar that on the latest chips, no sense resistor is needed and ALL of the difficult is done "on-chip"....making interfacing very easy.
There are several, but a good start is the SLA7070M for example:-

Features
+ Power supply voltages, VBB : 46 V(max.), 10 to 44 V normal operating range
+ Logic supply voltages, VDD: 3.0 to 5.5 V
+ Maximum output currents: 1 A, 1.5 A, 2 A, 3 A
+ Built-in sequencer
+ Simplified clock-in stepping control
+ Both full/half-stepping, and microstepping versions; microstepping versions (SLA7075M, -76M, -77M, -78M) are capable of full-, half-, quarter-, eighth-, and sixteenth-stepping
+ Built-in sense resistor, RSInt (NEW)
+ All variants are pin-compatible for enhanced design flexibility
+ ZIP type 23-pin molded package (SLA package)
+ Self-excitation PWM current control with fixed off-time For microstepping parts, off-time adjusted automatically by step reference current ratio (3 levels)
+ Built-in synchronous rectifying circuit reduces losses at PWM

You can download the data sheet and many others, here:-

http://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CC4QFjAA&url=http://www.allegromicro.com/en/Products/Sanken-Products/Sanken-ICs/Sanken-Motor-Driver-ICs/Sanken-Stepper-Motor-Unipolar-Driver-ICs/~/media/Files/Sanken/Datasheets/SLA7070M-SLA7071M-SLA7072M-SLA7073M-Datasheet.ashx&ei=1HyoU_fMN6fpywOU04K4Dg&usg=AFQjCNG1FcfknRgt1p6azYSXmfTlusOg6w&bvm=bv.69411363,d.bGQ

Best of luck

Andy
 
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