SetAnalogfrequency Function

[IFX-Anusha]

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Implementation of setAnalogwriteFrequency function and documentation
Tests are also implemented

[jaenrig-ifx]

Shouldn´t this storage of the freq in pmw instance attribute be done even if the object is initialized ?

So, no else (block 212-214), and 2 nested "ifs" instead of one in line 206: one for checking if pin is matching, and other for initialzation? If init -> change freq, if no init, we still set the pin freq.

Otherwise if we call setAnalogWriteFrequency(), and the writeAnalog() it will take the default frequency. Or am I missing something?

[IFX-Anusha]

Yes, that was a mistake. What do you think about now, or should it be changed to a nested if?

Now that will store frequency in all cases and if pwm is initialised and pin is matching then there is a change in freq

[jaenrig-ifx]

Mmm, but you only want to change the frequency of the pin passed by argument... not of all pins.
That is why I suggested the 2 ifs... But any other mechanism you can think of.

[IFX-Anusha]

Yes that is done

[ramya-subramanyam]

If you also check here for both the conditions, like pwm[i].pin == pinNumber || !pwm[i].initialized,
and then assign both the attributes even if the pin was initialized/ not initialized,
pwm[i].pin = pinNumber;
pwm[i].frequency_hz = frequency;

it will simplify the implementation no?
you can then remove the lines from 218 to 225 completely.

[IFX-Anusha]

Yes that is possible. But I have a question about this that suppose we call

SetAnalogWriteFrequency( 9, 100) ;

SetAnalogWriteFrequency(8, 50);

Analogwrite( 9, 32676); - Then if this should work then we should have that additional lines 218-225 with an extra check for the pins used.

or else the data will be overwritten

[jaenrig-ifx]

What about implementing a function to allocate the pwm object?
pmw_t * alloc(pin_size_t pinNumber);
The function returns a pointer to the matching pwm[x] object in the array. If that pin is not yet allocated to any of the array objects, it allocates it. Return nullptr if all the positions are allocated.

With that the logic in analogWrite() could be simpler?
In pseudocode:

pmw_t *pwm = alloc(pin);
if pwm is nullptr then return

if not  pwm->initialized then we cyhal_init() and pwm->initialized = true
prepare args for set_duty()
set_duty()
start()

And in setAnalogWriteFrequency() :

pwm_t *pwm = alloc(pin);
if pwm-is nullptr then return

pwm->frequency = freq;
if pwm->initialized then set_duty()

[IFX-Anusha]

Yes that is a good approach. Done

[jaenrig-ifx]

👯 good!

[ramya-subramanyam]

Looks good!