thank you thank you thank you sparkfun! I don't know who convinced you guys to do this but I am ever so very grateful. I was going through the painful process to designing such a board myself. Now I don't have to. To God be the glory.

Hi together,

I was very satisfied running l6470 with low-cost and low-torque Motor. But now I bought an SECM264-E2.0 Stepper that is Microstepp optimized and have a nice Torque.

So I would like to use it in Bipolar Parallel Mode and the Data for that would be: Current/Phase: 2.8 A (would like to use it at 1,8 A) Resistance/Phase: 0.7 Ohm Inductance/Phase: 1.4 mH

But I don’t want to push the Motor and Driver Chip to the Edge so I would set it to 1,8 Amper! BEMF Compensation gives me those Values:

//parallel with 1.8 Amper

dSPIN_SetParam(dSPIN_KVAL_HOLD, 0x07);

dSPIN_SetParam(dSPIN_KVAL_RUN, 0x26);

dSPIN_SetParam(dSPIN_KVAL_ACC, 0x26);

dSPIN_SetParam(dSPIN_KVAL_DEC, 0x26);

Now it comes the tricky Part. I have to run this Stepper at Speed around 2 Steps/Second !!!

At this speed and this low Voltage (1,8 V) Motor makes very very strange and absolute not satisfied movement. I know that there is an option called SetLSPDOpt in Script, but setting this at true does make no difference.

It seems that this drive is not suitable running strong stepper at low speed?

I tried connecting it in serial so that at least Voltage would be bigger, but here my Motor would become hot after 5 Minutes running low Speed.

Did someone noticed those problems or am I the only one?

We ran into problems reading ABS_POS on an Arduino board, too. The problem seems to be in the dSPIN_Param function in file dSPIN_support.ino.

C silently converts types shorter than int to int prior to any arithmetic operations. Ints in Arduino are 16 bits, so the left shift operations on the bytes returned by dSPIN_Xfer don't work as intended with 16 bit ints.

Consider how dSPIN_Param handles the first byte returned from dSPIN_Xfer:

if (byte_len == 3) {
    ret_val |= dSPIN_Xfer(...) < < 16;
}

dSPIN_Xfer returns a byte, and it is silently converted into a signed, 16 bit int, and then it is left shifted 16 bits. A 16 bit value shifted left 16 bits is 0. So the most significant byte of the ABS_POS is effectively ignored. Surprise #1.

The next byte is handled the same way, except it's shifted left 8 bits, but this also causes an unexpected result. Suppose dSPIN_Xfer returns 0x80. It's first converted to an int (0x0080), then shifted left 8 bits (0x8000). But this is now a negative value in a (signed, 16 bit) int. So when it's converted to an unsigned long to be OR'd with ret_val, it's converted to 0xFFFF8000. Surprise #2.

The solution that worked for us was to explicitly cast the value returned by dSPIN_Xfer to an unsigned long. This forces the conversion of the 8 bit byte to a 32 bit value, which is long enough to handle the left shifts properly.

ret_val |= (unsigned long)dSPIN_Xfer(...) < < 16;
...
ret_val |= (unsigned long)dSPIN_Xfer(...) < < 8;
...
ret_val |= (unsigned long)dSPIN_Xfer(...);

(It's not strictly needed in the last case, but I like consistency.)

I suspect the original code was written for a system that used 32 bit ints, on which the left shifts would have worked as intended.

I hope Sparkfun will change the example sketch to save other from this subtle bit of C behavior.

In your dSPIN_example sketch I see an anomaly. In the file dSPIN_support.ino the function AccCalc claims to need to multiply stepsPerSecPerSec by 0.137438 but that figure is not supported by the maths:

// The value in the ACC register is [(steps/s/s)*(tick^2)]/(2^-40) where tick is 
//  250ns (datasheet value)- 0x08A on boot.
// Multiply desired steps/s/s by .137438 to get an appropriate value for this register.
// This is a 12-bit value, so we need to make sure the value is at or below 0xFFF.
unsigned long AccCalc(float stepsPerSecPerSec)
{
  float temp = stepsPerSecPerSec * 0.137438;
  if( (unsigned long) long(temp) > 0x00000FFF) return 0x00000FFF;
  else return (unsigned long) long(temp);
}

According to my calculations the required value would be:

1 / (2^-40 / (250e-9)^2) = 0.068719476736

Not 0.137438.

The inverse of 0.068719476736 is 14.551915228367.

That agrees with the datasheet (page 40) which says:

The available range is from 14.55 to 59590 step/s2 with a resolution of 14.55 step/s2.

And multiplying 14.551915228367 by 0x8a gives 2008.1643015146 which is what they say the default setting for the ACC and DEC registers are.

Am I missing something? Is the datasheet wrong? Or the code wrong?

The other calculations in that file check out, it's just this one that doesn't match up.

Question: If the absolute position counter is +/- 2^21, and I am set for 1/128 uStepping with a 200 steps/rev motor, then I can only turn the stepper +/- 81.92 revs from zero before losing my position???

Does anyone know how can i set up the Microsteps in this driver?

Nothing is more fun that product quirks! (ST's product, not sparkfun's :) So buyer beware! The L6470 has an internal 8-bit data latch that it uses for all SPI communications (that's why it's so easy to daisy chain them on the same CS). However, it does not ignore CK (serial clock) when CS is deasserted! Thus, if you're SPI master happens to have a quirk of toggling the clock line in between messages, say like the MCP2210 does, then you'll end up with responses where each byte is shifted left a bit, LSB always zero, MSB missing.

In case you happen to run into this, you can work-around the problem with an inverter on the clock line and configuring the MCP2210 to use CPOL = 0 (so SPI mode 2), since it doesn't have this hiccup when CPOL = 0, and the inverter will put the clock back in the correct polarity.

sparkfun, on your next revision of this, can you please use the POWERSO-36 package? :) :)

Hi Techsupport Team, We ran into problems reading ABS_POS on Arduinio Board.. maybe you already know about this problem It seems to be the 8th Bit from the 22 bits Position register is always Low other reset.. All the other functions are working good but of course I don´t be able to read the Position values correctly

In Order to find the solution i´ve tried following:

1. I tested all the possible solutions (taked from: https://www.sparkfun.com/products/10859) that other users have suggested with any succes.
2. I tried to implement new methods of the Autodrive library (https://github.com/sparkfun/L6470-AutoDriver/tree/master/Libraries/AutoDriver) in the old Arduino code and it has not worked
3. I Consulted/Posted on the ST microelectronics Forum about my Problem but I could not find a solution (You will see that other custumers experimented the same issue even with the evaluation board EVAL6470H).

Im need to ask if you could reproduce this error in your labs, it looks as many costumers have experimented the same situation. We need to be shure that your code works or we need to find other Hardware options at right time.

Thanks !

This is a really expensive breakout board... The part is $3.40 in volume. I understand that breakouts have a markup, but this is a lot.

Hi, after some fiddling around I got the dSpin running with an Arduino Uno. But I experience strange behaviour of the “move” command: when issuing 200 Steps it just moves a little bit, only when passing ~25000 steps it moves one whole revolution. Any ideas where that could come from ?

I’m using a Nema 1,2A 1,8° Stepper, Arduino and the dSpin. moritz

Hello, guys. I happened to use the exact same stepper driver. It is powerful without any doubt, however, I found there existed some problems. I can control my stepper with my 51-MCU, but the maximum speed of the stepper 4.5r/s, that is, 900 steps/s or 270r/min, it is too slowly! I just have no idea how to fix it. And, I found the current is just 300mA at most. Strange. Any one can help me? Thanks in advance.

OK sparkfun, it's complaint time:

• You're schematic refers to JP1, JP2, etc. They aren't printed on the board.
• You're schematic refers to VS, but the board only has a V+ printed on it.

Less confusing are these inconsistencies between the board & schematic:

• BUSYN != BSYN
• FLAGN != FLGN
• STANDBY != STBY
• OUT{1,2}{A,B} != O{1,2}{A,B}

Can guys pretty please either:

• update your schematic
• provide a picture that shows which JP is which with either a photo of the board or a diagram (my copy if geda isn't reading the eagle file for some reason).
• At the very least, make a tiny text file that clarifies these items, eg.:

Errata: V+ on the board is VS in the schematic The jumper with the pins V+ and GND is labelled J5 in the schematic

etc. Thank you!

// there has been alot of discussion as to where or not you can use the L6470 driver

// for milling machines and many other purposes where 2 or more motors

// need to be synchronized as well as have dynamically assigned speeds.

// the problem is there is no clear/actual way to change the speed register wile the motor

//is running, some have suggested to just use the L6470 in step at a time mode

// but I feel this is a waste of allot of great features ie stall detection.

// So without further adue here is a solution

Code:

void loop()
{
  // 200 steps is one revolution on a 1.8 deg/step motor.
  dSPIN_Move(FWD, 40);
  while (digitalRead(dSPIN_BUSYN) == LOW);  // wait Until the movement completes, the
  dSPIN_SetParam(dSPIN_MAX_SPEED, MaxSpdCalc(max_speed_rise)); 
  max_speed_rise += acceleration_rate; 
  if (max_speed_rise > 100){
    acceleration_rate = -1;

  }
  if (max_speed_rise < 1){
    acceleration_rate = 1;
    delay (1000);
  }

}

if you run this you will see that the stepper s acceleration

//is nice and smooth while still being controlled dynamicaly ( wile the motor is

// running ) It is a very simple work around ...

In truth the motors speed is changing in-between move commands,

but this is happening so often that it is very smooth!

// now the comes the part thats not done yet ... daisy chaining, // using the method dynamic speed method combined with daisy chaining // one more thing ... load all the bits but one on the daisy chain while the // motor is finishing the previous command then using an interrupt as soon as // the L6470 busy pins are all low load the last bit in the daisy .. // this should reduce any delays that could cause motor noise!

Shoot me a message if you improve on it, or the methods iv spoken of.

Some links to my project related to this post

https://github.com/Rylangrayston/ard...ee/Daisy-L6470 // youcan find the full code here!

http://www.blenderartists.org/forum/...!-Suzans-Dolly

http://rylangrayston.github.io/arduino-blend/

Anyone get the L6470 to run without constantly reporting stall errors on A and B?

i wish there has been some tutorial stuff for the example sketch. so i researched, tried and errored. here's my result: Image of wiring

The schematic shows a 200KOhm variable resistor "R4" connected to "ADC" (pin 5). I looked all over the board I have in my hands, and I can't find R4 anywhere. Am I going blind?

Hello,

Thanks for the board, it save a lot of work for me.... well almost :-) Just one question, everything seemed to be working, but I'm not sure how to use the sample code. The motor just runs back and forth calling dspin_run. I expected that it would go one full revolution for this motor (https://www.sparkfun.com/products/9238).

Can this board be used in a pure SPI mode? I only want to use SPI so I've connected only the SPI lines with arduino. In fact, in my loop I just do:

dSPIN_Move(FWD, 128000); while(dSPIN_GetStatus()) delay(500); dSPIN_SoftStop();

I'd appreciate any direction I can get. Thanks in advance guys.

cc

Hi guys,

I just plain need help here. Please don't respond with "If you don't know what you are doing then, don't try it", because nothing is more bothersome than someone telling me not to seek help.

Has anyone written a tutorial on using this break out board with an Arduino Uno R3? I know you guys are operating with a level of knowledge far above mine, but I've spent a day just trying to get the board to work with my controller and a stepper motor.

I'm suffering from the "Code is documentation" problem. It seems like anyone who has written something online about this is operating under the assumption that every reader is a programming guru. If anyone has the heart to write up a basic tutorial for wiring up a test rig, and show which calculations are important to get a motor turning then I promise I will share all my future developments with the community.

I'm hoping to use these chips to drive 3 stepper motors for a 3 Axis CNC machine, with the goal of having it up and running by April 2014. I've got a router up and running on GRBL with a CNC shield before. This is my attempt to get into the nitty gritty. Who knows months from now I could have a decent setup, but any help just getting started would be much appreciated.

I am running into problem trying to reduce the speed once the motor is running. I am using the dSPIN_Run command, and have no trouble ramping the speed upwards, but then when I try to ramp back down by passing in lower values, the motor just keeps running at the same speed. This behavior continues until I pass in 0 (zero) as the Run speed, at which point the motor stops as expected. Note that my accel and decel params are set to 0xFFF which should give me infinite accel/decel. Min Speed is set to zero. BEMF is disabled.

What am I doing wrong?

Hi guys ! I am trying to connect this Easy Driver to my micro-controller. However, I do not see a "STEP", "DIR" and "GND" pin on the easy driver. What connections should I make between the Arduino and this easy driver (as in which ports to use on the easy driver) to make the stepper motor rotate clockwise and counter clockwise.

Thanks

I'm trying to drive a micro stepper with the driver and have a small problem. The recommended current for this motor is 0.1A and the voltage 12V. I went over the specs a noticed that he lowest current limit is 375mA. Is there a way to limit the current even more? thanks

Anyone else notice that the power bridge outputs are labeled wrong on the board?

01B is where out2A should be and 02A is where out1B should be...

Has anyone gotten this to work with an Arduino UNO, and if yes would you please share with me your pin assignments? Using the sample code; my call to dSPIN_GetParam(dSPIN_CONFIG) always returns "0", so I think my communication isn't working, maybe due to my pin assignment choices.

On the UNO, pin 13 is hard coded to an LED on the board, so I reassigned pin 13 from SCK to STATUS1 and then used pin 2 for SCK, as shown below. However, as soon as SPI.setDataMode(SPI_MODE3)executes during the initialization, pin 13 goes high and will not come back down, even if I explicitly set it low with digitalWrite(13,LOW). I'm not sure what this means. I would greatly appreciate any tips or suggestions on getting this going with the UNO.

#define SLAVE_SELECT_PIN 10  // Wire this to the CSN pin
#define MOSI             11  // Wire this to the SDI pin
#define MISO             12  // Wire this to the SDO pin
#define SCK              2  // (was 13) Wire this to the CK pin
#define dSPIN_RESET      6   // Wire this to the STBY line
#define dSPIN_BUSYN      4   // Wire this to the BSYN line

#define STAT1            13   // (was 14) Hooked to an LED on the test jig
#define STAT2            9   // (was 15) Hooked to an LED on the test jig
#define SWITCH           8   // Hooked to the switch input and a pB on the jig

Can anyone tell me if this board is sensitive enough to give you a dSPIN_STATUS_STEP_LOSS_A or dSPIN_STATUS_STEP_LOSS_B status after loosing only a single step?

Can anyone tell me the process to initialize this driver. I am using FPGA Spartan 6 and PIC microcontroller. SPI interface I have coded and is showing correct in CRO. But no output at all from the driver. Please help me in the initialization process.

Hi everybody..I have a question if somebody could help:

Can i interface this board to a 24v relay output of a plc? The relay output of the plc will close every 5 min for about 10 sec. At this time i want to drive a NEMA 17 Bipolar stepper motor.That simple.. As you can understand the problem is that my plc has relay output, not transistors so i can't get a digital pulse (0 to 5v) but only dc 24v. Would this board do this job? Do i have to use a step down voltage regulator to convert 24v to 5v?

Thanks (sorry for my English)

.

Hello Sparfun!

We are using the L6470 and it is working quite well. But: We have problems when reading the ABS_POS register. It seems to be that the 8th Bit (for 128) is always Low. See Our values:

Go To Pos Returned values 127 127 128 0 129 1 255 127 256 256 383 383 384 256 385 257

and so on. seems that the 8th bit (of 22) for the value 128 is always low. Is this a common issue? Does anyone have this problem too? How to slove this?

I miss having access to OSCOUT and OCSIN pins. Access to these pins is critical in systems with multiple axes.

With a 3% frequency dispersion oscillator in each axis driver, how to synchronize the motion of the XYZ axes if one can’t propagate a common clock signal?

Hi everybody.. Im experimenting very strange problems with the L6470. my hardware set up is:

The motor is this one: http://www.phidgets.com/products.php?category=23&product_id=3317_1

Power supply:

http://www.ebay.de/itm/12V-1A-12-5A-12W-150W-AC-DC-Trafo-Netzteil-Driver-fur-SMD-LED-RGB-Strip-Strahler-/321016344889?pt=DE_M%C3%B6bel_Wohnen_Nachtlichter_Lichts%C3%A4ulen&var=510086915476&hash=item4abe10b139

My issue:

I can not drive the motor in speeds high as 1000 steps/sec.. Actually had already achieved very good speeds with the same motor (above 5000/sec) .. but now I tested around 5 chips and simply does not work so fast anynmore..

I suposed that is a current issue... I tested all posible configurations in the "kval_hold kval_acc kval_run=1b st_slip= int_speed fn_slp_acc= 8a fn_slp_dec" registers I measured the current in the coils and does not exceed 0.5 Am Also made a Test with a very small motor which actually can turn very fast but with very low torque( I can stop the motor while it runs touch it only with my fingers)

I tested the default set up from dSpin evaluation software for Windows but nothing works...

has anyone eyperience with a similar issue...??

Thanks??

Hey guys, noob question from a ME with just enough EE skills to be dangerous with a soldering iron.

I'm trying to figure the wiring between JP1 on the L6470 breakout board and a Nano. Based on my read of the dSPIN_example.ino file, I get JP1 pins 4-9 and 2, but am unsure if I need to do anything with JP1 pin 3, and also unsure of the corresponding connection from the nano to JP1 pins 1 & 10 (pwr & gnd).

Also, can anyone de-convolute the following line from the top of the dSPIN_example.ino file for me?

define SWITCH 8 // Hooked to the switch input and a pB on the jig

I get that is is pin 8 on the Arduino, but can't suss "switch input and a pB . . ." etc.

Thanks!

Well, I just got the thing working. Like others have said, each and every command has to have the CS cycled. If it is a multiple byte command, you need a cs cycle for each byte. If you want to get data back, you need to send a 00 (nop) to it after you send the data request command, wait for the sent flag in the SPI to raise, wait a bit, then read the spi data register. And cycle the cs for each read.

Also, make sure you have the Standby/reset high.

Oh, yeah....you do need to have main motor power (VS) to the board. It is not enough to supply 5V to the 5V terminal. If you don't have motor power to the board, all you'll read is zeros....(ask me how I know this).

Also, like was said earlier, you should setup the param registers. Get the software from the ST website to get the proper values. Your motor will run smoother and better.

I am currently driving a ROB-10847, with about 15 volts to the VS, and the board doesn't even get warm....'course that is unloaded.

Its a really nice board/chip. Smooth and easy. Once you can talk to it.

I want to read and write registers of L6470. Do i need to make the Flag pin high or low? another question is i cannot read any register , i cannot read signal no MISO line ? any suggestions?

I used the 6470 breakout in my first arduino project and it was a great experience. The example sketch had my project running with minimal programing on my part. I would recommend this driver to anyone who needs to control a stepper motor. I found this video from ST informative. Thanks Sparkfun http://www.youtube.com/watch?v=4LEOW4h7YBY

I am using SPi bus in the following way to read and write L6470 registers. it would be nice if someone could tell me what mistake i am doing. I cannot get signal on SDO pin when i try to read any register

void spic_init_config_L6470() { PORTC.DIRSET = SPIC_CS ; PORTC.DIRSET = SPIC_MOSI ; PORTC.DIRSET = SPIC_SCK ;
// Configuration of SPI bus for port C
SPIC_CTRL |= SPI_ENABLE_bm |SPI_MASTER_bm ; // Set Enable bit in control register using bit mask and SPI in master mode SPIC_CTRL |= SPI_MODE_3_gc; // Set SPI mode. //SPIC_CTRL |= SPI_PRESCALER_DIV4_gc; // Choosing the freq, we have chosen the max freq

//SPIC_CTRL |= SPI_PRESCALER_DIV16_gc;                           // Choosing the freq, we have chosen the max freq

SPIC_CTRL |= SPI_PRESCALER_DIV64_gc;                           // Choosing the freq, we have chosen the max freq

//SPIC_CTRL |= SPI_CLK2X_bm;                                    // Doubling the SPI speed (SCK freq) in Master Mode      
SPIC_INTCTRL |= SPI_INTLVL_OFF_gc ;                           // Disabling the interrupt 
SPIC_STATUS  |=0;  

}

dSPIN_rx_data =dSPIN_Get_Param(dSPIN_ACC);

uint32_t dSPIN_Get_Param(dSPIN_Registers_TypeDef param) { uint32_t temp = 0; uint32_t rx = 0;

/* Send GetParam operation code to dSPIN */
temp = dSPIN_Write_Byte(dSPIN_GET_PARAM | param);         // param is the respective register address listed in table 12 of data sheet 
/* MSB which should be 0 */
temp = temp 

I am using L6470 chip and trying to read and write any register.if i want to write ACC register, i need to send three bytes. First byte is the command byte and then following are two bytes to write the value on register. My question is do i need to make the chip select pin high after i write each byte ? or i should write all three bytes and then make the chip select pin high? i use actually both ways and tried to write the value and then i tried to read it , i could not get any signal on SDO line. I can only see CS.CK and MOSI pins. I am using Atxmega 1283

Wondering if anyone has the example compiling under Arduino 1.0+, it would be mighty helpful. Usually don't have any issues and have followed up what was recommended during the effgee / hendorog comment, but no luck. Much appreciated.TIA.

I have had success now getting a Raspberry Pi to communicate to the board and it looks like I am getting valid data back from it. However I don't have a small stepper around right now so I have not connected anything to the bridges on the chip. I'm wondering if in that case it is normal to get 'weird' status values? My STATUS register reports either 0x7C03 or 0x7E03 which indicates that all or nearly all possible error conditions are flagged and they stay that way no matter how many times you send the GET_STATUS command. I was figuring that it's possible that with no motor attached it's royally unhappy with the situation but would be nice to confirm that. I have a couple NEMA17's on the way to give it something to connect to.

Meanwhile I'll keep plugging away at writing an interface to this thing in C++ for the Pi.

Hi: Im i want to use the l6470 driver with the Arduino Ethernet Board.. is that posible? Thanks

Would be great if some guru could create a basic demo project for arduino. I can't get the example here to compile, it seems to be structured all wrong for the arduino IDE (4 separate INO files is like 4 separate projects to my understanding). I've copied source from 3 of the files into a single support.h file, but the IDE sitll complains

"In file included from dSPIN_main.cpp:3: /dSpin_support.h: In function 'long unsigned int dSPIN_Param(long unsigned int, byte)': dSpin_support.h:325: error: 'dSPIN_Xfer' was not declared in this scope"

Update... got the little bugger to talk (need to cycle chip select every byte in and out).

Now I know why you guys are called Sparkfun. Tried to change to 128 microstepping and zaporama on what appears to be the bootstrap cap. Sparks a flying and one L6470 is toast.

Good thing I bought 6.

By the way, setting parameters on this guy is very tricky, even with the ST Evaluation software.

OK. I give up. I can not get comm working with this chip. Does anyone who has got it to work have any clues as to why the @#$%* thing sits there as mute as a mummy? I have interfaced a lot of SPI chips with no where near this level of trouble.

I've been using this motor driver for a few months now and love it. I originally bought the evaluation driver and communications kit from ST Microelectronics and then decided to try my hand at writing my own library. I am running it with the ATXMEGA128A1 @ 3.3V and it works great. If you can't communicate with it, make sure that you drive the STBY pin high (it took me a while to figure this out). Another issue I ran into was that there seems to be a lag in the busy signal.

I use the commands:

while (!(PORTF.IN & PIN3_bm));

_delay_us(Encoder_Read_Delay);

Move_REL(StepsToMove,Direction);

I wait ~20µs between when the busy signal goes high (signalling an end of move) to when I can send the next command, I'm not sure why this is.

I haven't had any thermal issues unless I try to over drive the motors by increasing the duty cycles for KVAL_ACCEL, KVAL_DECEL, KVAL_RUN. To get more torque I just went to a bigger motor. To figure out your motor parameters download the dspin software from ST Micro and use the BEMF calculator.

My one complaint is that the spacing of the pins is not uniform. I ended up directly solding wires to the board, but it would be nice to have connectors on it. Maybe SparkFun can offer compatible connectors in the related products? Other than that, this is a great product and the 128 µ-stepping is really smooth and really quiet. It is great to have this driver handle all of the pulsing and calculations. Simply tell it speeds, directions, accelerations, etc. and it does the rest!

Hi, I'm confused on how to wire this up regarding logic power. I've got an external power supply for the motor which I connect to V+ and GND (guess this is JP5 on the schematic) and so I connect BSYN,STBY,FLGN,STCK,SDI,SDO,CSN,CK as described in the Example Sketch. But what would I connect to pins: 5V and GND on JP10? What about ADC, V and SET? And SW and GND? I've tried to read and understand the datasheet the best I could and I've made some connections, that makes it function, however I get some weird not expected signals on the SDO line and occasionally it makes the motors do unexpected stuff.

I would love to see an example wiring diagram for Arduino/Netduino, thank you.

Hi..I have the v1.1 board...in the datasheet said this: "VDD is not internally connected to VREG, an external connection is always needed."....and in the eagle draw Vreg is unconnected...any problem with working whitout Vreg pin? Can you help me with the ADCin pot...example please

Folks,

Have to say I'm a bit disappointed by ST with their 3A RMS rating on the chip. This is not continuous according to their Applications Engineer! I even bought two of their 4 layer boards thinking this would be the best case thermal layout.

At this current the normal package could get up to 279 Celsius and the PowerSO package could get up to 160 Celsius. Chip is rated for max of 150 Celsius!

Thanks Sparkfun for the Arduino code!

Tip for new users. There are many parameters to configure in this chip. Go to the ST website and download the dSpin evaluation software for Windows. Click on the BEMF compensation menu, enter your motor parameters, and hit evaluate. This will then spit out a bunch of device configuration values that you should add to the Arduino code. Before I did this, there was a lot of strange motor behavior. The AN3991 app note also describes how to measure the Ke value (V/Hz) using a scope. You need to enter this for the BEMF compensation. I'm still messing with this chip but with the EVAL6470H board from ST that can supposedly handle 3 amps. Here's the ST link to the files:

http://www.st.com/internet/analog/product/248592.jsp

I just received my 2 boards. Is it possible to easily "patch" them with respect to the missing VReg cap ? On the schematic the VReg pin seems to be unconnected, and thus soldering something on the pad does not seem to be an easy task.

TIA for any suggestion.

Hi

Do you have a Arduino/Netduino connection and code example?

Thank you Kristoffer

According to the data sheet "In order to make the voltage regulator stable, at least 22 μF should be connected between VREG pin and ground (suggested value is 47 μF)."

As far as I can see on circuit diagram, there is no cap connected to VReg, yet it is (apparently) used as part of the reference for the A-D for doing the motor voltage compensation.

Why does the new product video mention 1A when the part is advertised as 3A? Makes a difference in driving NEMA 23 motors.

I don't suppose you guys use DreamSpark, and have produced a 3D model of this?

BTW guys you should have the thermal vias as recommended by TI (www.ti.com/lit/an/sloa120/sloa120.pdf). I've seen a guy run a NEMA 34 motor with this on one youtube vid (http://www.youtube.com/watch?v=MOhjx7oEM4A)