L6470 problem: continuously read out status register

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Posted on December 21, 2012 at 16:16

Hi,

I�m playing around with the L6470 which finally worked quite well. But now I�m experiencing the following issue: I want to continuously monitor the status register of the L6470. But when I send a �run� command to the device immediately after using the �GetParam� command to read out the status register the motor does not move. If I do it the other way around i. e. when I first send the �run� command and then the �GetParam� command the motor turns as intended but I receive zeros (&H0) for the status register high and low byte. Have done something wrong or is it actually the case that there has to be a pause between sending two commands via SPI? If so, how long is this interval? And just to clarify: that would also mean, that there is a maximum frequency for changing the motor speed (e.g. it is not possible to send a new speed value at e.g. 1 kHz as needed for a quick control loop)? I would very much appreciate any helpful hints. Thanks a lot! Best, Malte #l6470

[post]

Posted on December 21, 2012 at 18:45

problem solved!

I'm sorry - I had a stupid error in my code that caused this behavior. I only transmitted two bytes instead of the necessary three bytes for the speed parameter of the run command via the SPI bus. The missing byte led to a misinterpretation of the next byte received.