Emergency Stop on Custom Hardware

Hi Thomas,

ThomasV said:

Right now I can use GPIO-28 and 29 for this, how would I go from here?

You want to use GPIO28/29 as emergency stop button -- So do you want to pause the code or reset the code or just stop the code?

Regards,

Gautam

I guess just stopping would be okay, wouldn't it? It would be used in case the motor is showing bad behaviour. I suppose adding this kind of emergency stop is always better than just disconnecting the power supply?

ThomasV said:

I guess just stopping would be okay, wouldn't it? It would be used in case the motor is showing bad behaviour. I suppose adding this kind of emergency stop is always better than just disconnecting the power supply?

I guess you would be using ePWM module for motor control right? If so you can configure tripzone to stop the execution. What do you feel?

Regards,

Gautam

Gautam Iyer said:

I guess just stopping would be okay, wouldn't it? It would be used in case the motor is showing bad behaviour. I suppose adding this kind of emergency stop is always better than just disconnecting the power supply?

I guess you would be using ePWM module for motor control right? If so you can configure tripzone to stop the execution. What do you feel?

Regards,

Gautam

[/quote]

So I don't need to add a stop button you mean?

To give you a view of the situation: my mentor wants to keep open the possibility to add a second motor to the setup, so we will also bring out GPIO6 to 11 (that support ePWM4-6 A and B) from the controlcard to header pins. We can then later add our own electronics to connect the second motor. Do you think something like this is possible?

ThomasV said:

this kind of emergency stop is always better than just disconnecting the power supply?

If you need to be within the Safety regulations, you need to cut-off the power to the motor (at least in Europe). You might activate a brake.

The second contact of the Emergency switch can be used to signal the computer of this situation.

ThomasV said:

So I don't need to add a stop button you mean?

I would first like you to study the Tripzone Sub-Module of F28069 that can be found in Technical reference manual.

ThomasV said:

We can then later add our own electronics to connect the second motor. Do you think something like this is possible?

Offcourse, you can utilize these PWM modules through header pins later.

Regards,

Gautam

Gautam Iyer said:

I would first like you to study the Tripzone Sub-Module of F28069 that can be found in Technical reference manual.

I will.

Offcourse, you can utilize these PWM modules through header pins later.

So do you recommend also bringing out IOs that support trip zone for the second motor?

I see that GPIO12,13,14 are used now in my current setup.

ThomasV said:

So do you recommend also bringing out IOs that support trip zone for the second motor?

In future if you want to use these pwms then its recommended.

ThomasV said:

I see that GPIO12,13,14 are used now in my current setup.

So, do you've any alternate for these GPIOs in future?

The possible GPIOs for TZ1 are 12, 42 and 50. For TZ2 these are 13, 16, 28, 43, 51 and for TZ3 14, 17, 29, 52.

I don't know which of the functions they currently fulfill can be disregarded, so I don't know which ones I could actually use. Here are their functions:

12: LED-1
42: CAP3
50: Not used

13: OCTWn
16: SPI-SIMO
28: GPIO-28
43: DC_CAL
51: EN_GATE

14: FAULTn
17: SPI-SOMI
29: GPIO-29
52: /

It seems like I could use GPIO-50, 28 and 29. However, I am most likely going to use 28 and 29 for the START and STOP button (like on the DRV8301 board), because I am using their original IOs for something else. Regarding the other ones, I don't know what can be missed.

Also, when a IO is assigned to function as a trip zone, what actually happens to it, and can't it be used in any other way anymore? I ask this because I find it odd that GPIO12, which is assigned to LED1 on the DRV board, is used as TZ1. What does it actually do then?