Interrupt priority each 100us

[Milena]

Hi,

I have to make a interrupt each 100us. This interrupt should be priority on the BLE. In my interrupt I have only one condition (if/else) and I have to change PWM value.

Is this a problem ? Can I lose connection of BLE ?

My seconde question:

In the datasheet I don't find the total current on the uC ?

For one pin.... Which is true ?
On the page 151: it is writen : 14mA Max On the page 152 (Figure 25): it is writen: 25mA Max (for 3V3)

And how many pin I can apply this current ? (total current max)

Many thanks for your reply!

Milena

[Jørgen Holmefjord]

Hi Milena,

It is not possible to give the application priority over BLE. The softdevice have the highest priority level reserved for timing critical tasks. You can see the interrupt priority levels in the S132 softdevice specifications.

The current will vary with chip type and configuration. Which chip are you looking into? What current are you asking about? Current consumption or something else?

Best regards,

Jørgen

[Milena]

Ok, I put transitors! Thanks.

For my application I have to make a driver motor brushless. I have three coil and each 100us I have to change the coil and the PWM.

I will test with my EVM the precision of my interrupts of 100us. Do you know the critical tasks how long is it ?

[RK]

1. You need a transistor - this is in the datasheet somewhere - look for paragraphs about high and low drive strength and the max number of pins you can use with high enabled. It's a lot less than 60mA

2. If you are doing PWM then instead of trying to do it with interrupts, which isn't going to work very well, how about using the PWM module on the chip.

[Milena]

Ok, I put transitors! Thanks.

For my application I have to make a driver motor brushless. I have three coil and each 100us I have to change the coil and the PWM.

I will test with my EVM the precision of my interrupts of 100us. Do you know the critical tasks how long is it ?

[RK]

the timings are all in the softdevice spec, although they seem harder to decipher than they used to be. Either way - people keep trying to do PWM with interrupts and it never works. Please use the search feature and read some of the hundreds of questions about PWM, PWM with interrupts, PWM with the softdevice and any other variation. You need to use the hardware PWM peripheral or another non-interrupt based solution.