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Regular Guy
Joined: 04 Jun 2017
Posts: 110
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| Assembler 74HC165 Serial In,Parallel Out Shift Register |
 Posted: Sun Jun 27, 2021 7:20 pm |
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| Quote: | Shift registers are used to convert serial data to parallel or vice versa. "Talking" to shift registers
is a good way to get started learning about serial communication. Shift registers are useful as
parallel output and input ports which may be interfaced with a PIC16 serially.
For our first example, we will use a 74HCl64 which is a serial in, parallel out shift register. The
"in" vs. "out" designations are with respect to the shift register. The object is to create and send
8 bits of data to the shift register serially and look at its outputs via DVM, LED's or whatever to
see if the byte got there successfully. |
We will post our Mini Board for this experiment.
It is on the way to us.
Will post code too.
This is from PIC'n Up The Pace
Like author says we think this is good place to start.
With all the kinds of serial communication.
Anybody familiar with this?
Thanks!
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temtronic
Joined: 01 Jul 2010
Posts: 9588
Location: Greensville,Ontario
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| Posted: Sun Jun 27, 2021 7:43 pm |
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| yes, used 1000s of them before PICs..... |
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Regular Guy
Joined: 04 Jun 2017
Posts: 110
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Ttelmah
Joined: 11 Mar 2010
Posts: 19966
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| Posted: Mon Jun 28, 2021 12:03 am |
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SPI, is 'shift registers'.
The receive part of the PIC SPI, is an 8bit shift register. The send part
another. When you send a byte, it is parallel loaded to the shift register,
and then the hardware clocks this out as a serial stream, with the clock.
At the same time any data presented to the input pin is clocked with the
same clock into the other shift register.
The receive part is a serial in parallel out register, and the transmit
a parallel in serial out register.
You can generate the output part of this in software. Receiving (except
at lower clock rates), is harder.
The only thing 'special' about SPI, is that unlike most hardware shift
registers, the ones used for this allow you to specify which clock edge
is used, both on the transmit one, and the receive one.
So an 8bit shift register can be loaded with 'software SPI', or 'hardware
SPI'. |
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Regular Guy
Joined: 04 Jun 2017
Posts: 110
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| Posted: Mon Jun 28, 2021 1:03 am |
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Thank you Ttelmah
That is a 5 star answer! 
We feel that the board that has code send to it and lights LED's is for us.
Like it says in PIC'n Up The Pace.
The best starting point.
We feel that sending to another PIC is a 'moving target'.
You have the second code and hardware setup to debug.
Same thing with RS232 to terminal program.
You have the terminal program and settings to debug.
So.
Board with shift register and 8 LED's is for us.
Thanks!
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temtronic
Joined: 01 Jul 2010
Posts: 9588
Location: Greensville,Ontario
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| Posted: Mon Jun 28, 2021 5:15 am |
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no....
I replaced 74165s with PICs
Those modules are about $6, a PIC costing 50 cents can replace the 74165. |
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