Posts made by ChunkyPanda

@dc42 Thank you, that sounds great. I placed an order for a bunch of diodes and we'll see how the mod goes.

@dc42 Thank you for the quick response.

Oh no, I just bought 10 of the 1HCL and they are version 1.0a.

I guess I'm stuck with 1.0a for now... does it seem reasonable what I'm doing? i.e. two power supplies is parallel, 12V 0.1A with diode for constant power, and 24V 6A when motors can move?

Or is there some 1.0a board modification to get the similar V_AUX as 2.0? I'm looking at removing L3 or L4 (the inductors in series at the output of the buck) and putting 12V there, but if the above 12V 0.1A and 24V 6A works, then that is much easier.

I'm designing a CNC-like piece of equipment. The main board is the 6HC and will have several 1HCLs.

One requirement is that during an unsafe situation determined by dedicated safety controllers, for example door open, that motors on the 1HCLs are de-energized or not able to move. This cannot rely on software or firmware. I would like to keep communication at least with the main board.

If there was a dedicated power supply input for the motors that would have solved my requirement. The safety system would just supply power when it was ok to do so.

How can I implement this with what I have?

I was thinking of supplying constant board communication power (say 12 V, 100mA through a diode) to each 1HCL. If the safety system allows movement, it will switch on a 24 V 6A power supply that is wired in series to the power on the 1HCL allowing enough current for the motors to move. The reasoning is that the constant 12V 0.1A is enough to keep canbus communication happening, but not enough current to move the motor. Does this seem like a good idea? Are there any potential issues with this?

I also read, but cannot find it anymore, on the Duet website that the canbus boards are meant to be always available (i.e. always on), but that in some cases this can be managed. Does anyone know what this means? Is there a way to reliably power down and power up 1HCLs while the main board is running?

Thanks.

@droftarts Thank you very much.

I will not attempt to write to the register and risk damaging the board. I try to see if I can find other solutions.

Hi,

I'm wondering if there are any options when stopping the motor? I'm using a 6HC and also a 1HCL.

According to the documentation, M18 puts the motors into "freewheeling" mode, but there doesn't seem to be any options.

I'm looking for a way to short the motor coils to brake the motor without applying current.

I see that the Trinamic driver supports "coiling shorting" either on highside or lowside drivers when using the "standstill" (idle?) feature. This would work for me. Is there any way to access this feature?

Thanks.

@OwenD Thank you so much! That's exactly what I was looking for.

What is the best way to retain the value 16 arrays that will be restored after power cycling?

I have sixteen X & Y values I use for calibration for a project I'm working on. I declare the global variable in a macro and the value gets written and read from various other macros.

if !exists(global.xy_offsets)
global xy_offsets = { {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0} }

All is working ok, except when I power down, the values are gone. What's the best way to keep these values?

Thanks.