### PIC Based Oscilloscope Clock

PIC Oscilloscope Clock

For those are not into electronics, you must know that an oscilloscope has basically only one timebase to move the spot horizontally from left to right with the same intensity. The vertical deviation is function to the input voltage. You understand immediately that you can't directly display 7 segment digits, because you can't move the spot from right to left.

By using X/Y mode, where the spot is controlled on two axes by two different voltages, it is possible to draw a picture (as in the examples mentioned above), but a fast digital to analog converter with two channels and at least 8 bits of resolution would be needed.

So we have to deal with a spot that always goes from left to right in the same period of time.
If we want to have a 7segment-like display, we have to draw :

vertical segments : easy to do, just change voltage up and down quickly a few times.
horizontal segments : easy to do, just set a voltage level and keep it as long as you need.

By using 2 PIC outputs and a basic R2R digital to analog converter, we can have up to four different voltage levels : 3 for the vertical segment, and another one where to put the spot when it is not in use to draw a segment.

But the problem is that a 7 segment digit may have up to 3 horizontal lines at a time (like 2, 3, 8, 9..) but we can draw only one during one spot deviation.
So we will have to cheat with retinal persistence and use multiple frames : since we can have only one vertical segment per period, three periods will be needed to draw a full 7 segment digit.

Supposing we want to display 12:34:56 on the screen :

During the first period, we will draw all vertical segments, and horizontal upper segments only :

As a game, I let you try to find out the spot trajectory.
Don't forget the rules :

you can't go backward
you can't clear the spot

But you can move so fast vertically that the eye can't see the spot moving.

The lowest line under the digits is not significant, it his the place where the spot is parked when not used to draw a segment.

Schematic Diagram:

Attachment

Working Video

for more details see this LINK

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#### Conversation

Wed Nov 08 2017, 01:35 PM
Anirudh jain
I want to burn code in atmel 89s51 24pc 0329 but cannot get the connection with the burner. Can somebody provide me with the circuit diagram for connecting controller to burner. I'm using usb burner
Thu Nov 02 2017, 11:44 AM
karpal
write a program to exchange the content of b register with external RAM address 02CFH help me
Wed Nov 01 2017, 05:47 PM
sanae
i am using the DHT11 but i'm getting some errors in the simulate the programe in proteus 8 professional,: 1)cannot find model file 'DHTXX.MDF'.2)simulation failed due to netlist linker error(s).
Fri Sep 29 2017, 02:45 AM
Maaz
Wed Sep 20 2017, 12:36 AM
Ted
In a missing pulse detector using a 555 timer connected as a monostable vibrator with a PNP transistor,how does the positve input pulse turn on the PNP transistor?
Sun Sep 03 2017, 02:29 PM
martymarty
How do I connect an <NOKIA 1100 LCD > to an atmega328P ?
Sun Aug 20 2017, 10:23 AM
i am intending to interface sd card with STM32F4 and want to write a file in sd card using SPI protocol but using HAL only. Can anyone help me PLEASE!!!!
Sun Aug 20 2017, 10:22 AM
hello
Fri Aug 18 2017, 11:37 AM
hi @ angel patel i will attach a file i hope it will be helpfull for you
Mon Aug 14 2017, 09:57 PM

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