EVAL6470 operation via SPI

I raise nCS after each Byte transmitted, but the motor won't turn. I use a 1.5A stepper with 1.9mH impedance and a coil resistance of 1.56ohms. What are your register settings für KVAL, ACC, MAX_SPEED, OCD_TH, STALL_TH? Perhaps I did a mistake in the calculation of these values, but I recalculated it multiple times.

Okay...maybe a final question on the EVAL6470....

What motor current could it support with an attached heatsink (what ever would fit on it ;o)

Hello Mr. Poli

I would like to use the L6470....as ST was generous enough to send me 3 samples of it....

Main problem is that the UUSCI or UBI boards aren't available in Switzerland...nor are they available in short time from Digikey or Mouser Electronics....and since my EVAL6470 is fried now which I got form Mouser, this part has also now a long delivery delay. Also local distributor EBV has nothing on stock....

I thought something must be fishy with the SPI communication....but the datasheet states everywhere for the SPI communication the timing as ''TBD'' (o;

What would be really beneficial is an application note describing the different calculations of those register values and how they influence each other....and of course some layout guidelines....

I would really like to carry on with the L6470 as I believe it is superior to the Trinamic semiconductors TMC series....but the delivery delays throws me back at least 2 to 3 months now....so either go with the bulky L297/L6203 implementation....

...or ST is generous enough to send a new EVAL6470/UUSCI combination...

Besides..if you already have some preliminary application notes on the L6470..I would really be glad....

Last but not least I'm planning on publishing the development process of a small form factor CNC PCB with USB interface...and this L6470 would just be perfect for small CNC milling machines....no bulky external boxes anymore (o;

So far...thanx for your feedback...

best regards

richard

Hi Flavio

Also from Switzerland? (o;

We might to get in contact directly to share our experiences with stepper motor drivers then...my email: just swap my user name here and add @gmail.com...

Hello Mr. Poli

Hello Mr. Klingler,

I'll try to answer to all your points:

- We are aware of the shortage of STEVAL-PCC009V1 and STEVAL-PCC009V2 board. We are sure that new boards will be shortly available.

- The only ''critical'' time, as explained in my previous post, is the disable time. All others timings should be achieved from ordinary SPI interfaces of the most microcontrollers.

- We are not allowed to distribute draft versions of application notes.

- The current that the board can manage (in stady state) depends on the heatsink performance. The thermal resistance of EVAL6470 is about 40 °C/W, so the rms current that device can supply at ambient temperature of 25 °C is about 1.4 Arms for each phase.

If the thermal resistance is halved, the maximum rms current increase by sqrt(2) times (power dissipation is proportional to the square of rms current).

Regards

Enrico Poli

Dear Mr. Bassanello,

the board pages on the ST website will be updated soon.

You can find GUI and dll for the STEVAL-PCC009V1 on the following link:

http://www.st.com/internet/com/SOFTWARE_RESOURCES/SW_COMPONENT/SW_FUNCTION/steval-pcc009v1_sw_gui_v1_3.zip.

Best Regards

Enrico Poli

Dear Mr. Poli,

Hello Mr. Perucchi,

We apologize for the shortage of STEVAL-PCC009V1 and V2 boards. The interest on the L6470 led stocks to run out in a very short time. More boards will be available soon.

If you want, you can use the BEMF compensation tool integrated in the dSPIN Evaluation Software without any interface board; the software doesn't need a communication board to run.

Regards

Enrico Poli

Any update on this information? I note that the dSPIN is not compatible with Win7 64-bit. Will this be addressed?