Explain how this schematic works.

Schematic / IC Internally

Hello. i will try explain how it works internally from my understanding. i need help to confirm if i am right or not and to add on what i have missed out. Thanks you for reading this.

So this schematic is for a stepper motor driver. (attachment)

Point 1
Voltage get step down to 5V.

Question = why is there an extra cap? C4 ([Point 1]Compare) (attachment)
AND
How does it work internally? ([Point 1] See Page 7) (attachment)
i don't understand how it works internally and how 5V come out when input is more than 5V?
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Point 2 Pic ( lets not talk about programming but how it fetch the program )
PIC gets powered on by Pin 14
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*********** NOTE********* See attachment ([Point 2] See Page 15) as reference

When there is a voltage on pin 16 (high)
it generate OSC1 clock cycle.
internally in this OSC1 clock cycle there is 4 quadrature clocks, Q1,Q2,Q3,Q4.

So whenever OSC1 goes up and down Q1,Q2,Q3,Q4 will go up and down too..one at a time. (cycles continue)
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Program counter increase every time Q1 goes up
AND
instruction is fetched from PIC and put it in Q4, the instruction is decoded and executed in the next Q1 through Q4

So in simple term is it?...

when osc1 goes up once Q1 = Fetch program from PIC and put it in Q4 and it will execute and decode instruction
when osc1 goes down and up Q2 = it will execute and decode instruction
when osc1 goes down and up Q3 = it will execute and decode instruction
when osc1 goes down and up Q4 = it will execute and decode instruction

next cycle

when osc1 goes up once Q1 = Fetch another program from PIC and put it in Q4 and it will execute and decode instruction from the previous cycle.
when osc1 goes down and up Q2 = it will execute and decode instruction

and so on?..

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After that the data is send to PIN 6 and 7. and it goes to motor driver. (5804)

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here is the point where i got stuck.

beside on the infomation that is given from PIN 6 and 7, how does it turn the motor? i know how a motor turn..by energize the coil. but how it turn BASE on the data? i have to know internally how it works..any one can provide schematic on this? all i have is..5804 datasheet. (attachment)


also why do we have to put a resistor or cap before ground? noise? example in the schematic R6

thanks you all for read. =)

Point 2 - see page 15

Point1 has 6-35V going into it and 5V coming out , its a linear regulator. C4 is for decoupling high frequencies which C3 will not do.
looking at the motor driver, PIN 11 is the stepping input, one pulse in, one output pulse, so motor jogs one pole. PIN 14, is the direction, 1/0 it changes the phase of the two sets of pulses. So the processor should provide a stream of pulses to P11 except when the motor is braked, and P14 should have a 1/0 depending on the direction the motor is meant to go in.
How the micro supplies the above is hidden in its programming.
Frank

Many questions you're asking here. Many docs you want us to look at.

Is this about the operation of one device? Or many devices? Or about programming?

12MB of attachments to your question - are you serious!

Keith

chuckey said:

Point1 has 6-35V going into it and 5V coming out , its a linear regulator. C4 is for decoupling high frequencies which C3 will not do.
looking at the motor driver, PIN 11 is the stepping input, one pulse in, one output pulse, so motor jogs one pole. PIN 14, is the direction, 1/0 it changes the phase of the two sets of pulses. So the processor should provide a stream of pulses to P11 except when the motor is braked, and P14 should have a 1/0 depending on the direction the motor is meant to go in.
How the micro supplies the above is hidden in its programming.
Frank

Click to expand...

thanks a lot frank for reading and helping out here!!. i will google about how linear regulator work internally. inside the 7805.

BradtheRad said:

Many questions you're asking here. Many docs you want us to look at.

Is this about the operation of one device? Or many devices? Or about programming?

Click to expand...

i am sry about this. And it is not about programming. i need help on how the PIC oscalate and the driver clock.
The overview is a about a stepper motor driver...driving a hybrid stepper motor that's all.
on the schematic....i need to understand internally what is going on.
For example...

after input 6-35V to the 5V regulator. (WHAT HAPPEN INSIDE that makes it 5v)
and after that to the PIC (what happen inside?)
and so on.

(i have explain what i have know to my understanding...and i need to confirm if i am right or not and ask question..that is why it is so LONG)

keith1200rs said:

12MB of attachments to your question - are you serious!

Keith

Click to expand...

i am so sry. it because of 2 picture.bmp it is just 2 picture and 3 PDF file.


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Ok. i am so sorry about this. So now let me just ask 1 question that's all.

After the PIC send pulse and direction to motor driver (5804) how does this motor driver turn the motor?

i need help on how the PIC oscalate and the driver clock.

Click to expand...

The PIC combines a large number of functions that we would need to construct piecemeal in 'the old days'.
There are gains in ease of use, and lower parts count, and a reduced need to understand what's going on internally.

I have not used one myself but I have seen references to a crystal being attached to 2 pins, creating the inner clock oscillations. To make your own pulse train at a lower frequency, you can derive it by dividing down the main clock, or you can create it in software.

If you want to understand how a crystal oscillator works, there are articles showing how to make one from discrete components. There is series resonant, and parallel resonant. There are crystals made for various frequencies.