why would we connect a stepper motor driver to a PIC, and then connect it to the stepper motor?
why not just connect the stepper motor straight to the PIC ?
why not just connect the stepper motor straight to the PIC ?
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it is possible to design chip that will have brains as well as power and sometimes this is done too but it is inflexible. therefore most of the time it is much more practical to separate functionality. you may have a need for particular size stepper motor but someone else would rather use those outputs for something else.
if there was MANY people asking for PIC with built in stepper motor driver of one common size, i am sure someone would make it. the question is how many of them you want to buy? probably not more than few...
because the key is flexibility and everyone's needs are different, companies make component performing ONE function the best way it can. then you as a designer of a system need to pick all pieces and put them together (which is extra work), but - you can choose them based on your exact needs and application.
main objective for microcontrollers (PIC included) is to provide the smarts. to be universal or as flexible as possible, they need to be able to process information and use low power and therefore output levels are low. yes you can turn on an LED using just PIC output but that's about it (and an LED is a very very very small load). for 99.9% of other things you need peripherals such as other chips or discrete circuits. exact type will depend on application;
you need to drive small stepper - add stepper driver IC
you need to drive bunch of LEDs - add LED multiplexer IC
you need to make toy sounds on speaker - add audio amplifier IC
you need to drive large loads - add relay driver IC
same goes for input (you need to keep track of orientation - add gyroscope or compass IC etc).
if there was MANY people asking for PIC with built in stepper motor driver of one common size, i am sure someone would make it. the question is how many of them you want to buy? probably not more than few...
because the key is flexibility and everyone's needs are different, companies make component performing ONE function the best way it can. then you as a designer of a system need to pick all pieces and put them together (which is extra work), but - you can choose them based on your exact needs and application.
main objective for microcontrollers (PIC included) is to provide the smarts. to be universal or as flexible as possible, they need to be able to process information and use low power and therefore output levels are low. yes you can turn on an LED using just PIC output but that's about it (and an LED is a very very very small load). for 99.9% of other things you need peripherals such as other chips or discrete circuits. exact type will depend on application;
you need to drive small stepper - add stepper driver IC
you need to drive bunch of LEDs - add LED multiplexer IC
you need to make toy sounds on speaker - add audio amplifier IC
you need to drive large loads - add relay driver IC
same goes for input (you need to keep track of orientation - add gyroscope or compass IC etc).
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The PIC doesn't have the right voltage or current rating.