What is the best signal interface for PC ?

[_q12x_]

I mean.... the best and the easiest to use.
I remember back in the 2000's I used a serial interface, I think it was the printer serial port, 25 pins or similar. I believe I even used a mouse port as well, that versatile those systems were back then.
What I could do with it was ... program in C++ and pascal back then, using some imported dll's specific for communication with this serial port, I think it was port 40 or 25? It had a number is all I remember. And I could link to it any transistor base, back then I was working exclusively with BJT's, to light LED's, drive motors, beep some 8ohm I think they were speakers, drive a VU-meter LED bar I think directly from the port pins, without transistors, and also drive IC's , that was the time I learned about multiplexers and expanding the number of output pins. Also input sensors like LDR and buttons. I Loved that kind of easy and straight forward communication.
Today I dont know c++ or pascal anymore, but I am very good in c# and still use VS2010 because its very cool interface and very user friendly overall.
So I want you, to help me first of all, to find the hardware, the port I suppose or something more than a printer port, something more advanced and having more in/out's. The more the better. I want the best you can find for the moment. Best ideas or best adaptations, why not. As long as it's easy and stable to install and use.
And then, the software drivers and possible problems will appear along the way. I can debug a large majority of problems, I grow up debugging computer problems, so I have a 5'th sense for them. Im more concerned about the hardware part and the integration with my win7 that I still run today and my VisualStudio2010 for my c#. I know I still run old software but they are extremely stable and they don't f me up.
Thank you and I'm really curious what you will find for me.

 

[_q12x_]

-Was my answer clear enough after all? (as short as it was)

 

[marconi]

Hello. My#117 refers to my #115.

I think we have been at 'cross purposes':

Cross–purposes Definition & Meaning | Britannica Dictionary - https://www.britannica.com/dictionary/cross%E2%80%93purposes

 

[_q12x_]

Untitled 58.avi | ElectriciansForums.net | Free Electrical Advice - Electricians Forums: Electricians' Talk Forums

Untitled 58.avi for Electrical Videos on ElectriciansForums.net | Free Electrical Advice - Electricians Forums: Electricians' Talk Forums.

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I actually made the entire movinglight program like I did it with arduino..... in binary format and then converted in hexa and finally converted to encrypted bin file; But because that counter is counting to 5, is only displaying only the first 5bytes in the program. Im still thinking.... I made some previeous tests before this moving thing here and I can lit every individual led in the matrix if I find its coresponding byte code. Im very close....like that.

 

[_q12x_]

also a second movie to show you the progress and the problems as well.

Untitled 59.avi | ElectriciansForums.net | Free Electrical Advice - Electricians Forums: Electricians' Talk Forums

Untitled 59.avi for Electrical Videos on ElectriciansForums.net | Free Electrical Advice - Electricians Forums: Electricians' Talk Forums.

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[_q12x_]

Proteus sim p5 - I finished the logic to drive the Led Matrix Display

 

[_q12x_]

@marconi I believe you pressed a button and switch back and forth the letters already saved in the memory. You advanced 1 step that memory location with a press of a button. I observed/remember right?
Also I need help in this detail because is a bit too hard for me. Tell me how to advance to the next character.
Thank you.

 

[_q12x_]

Tell me how to advance to the next character in the RAM ? How you did it? I believe you pressed a button to do it, but how it was wired? please detail it for me. Thank you.

 

[_q12x_]

@marconi check this out, its on it's way before your package. It should arrive soon.
So I will have 2 RAM types to experiment with.

 

[marconi]

Before I wade in with any help(?) please clarify for me how you intend your logic to scan the LEDs of the 7 x 5 matrix. ie led by led, a column of 7 LEDs column by column left to right and then repeat or a row of five leds row by row top to bottom and then repeat.

My scheme is to scan the display column by column left to right and then repeat as in the attachment. In this test sequence the complete column of 7 LEDs is lit up, column by column.

 

[_q12x_]

Its not clear from my #125 movie?
here is the entire circuit diagram.

 

[_q12x_]

Please clarify for me how you intend your logic to scan the LEDs of the 7 x 5 matrix.

BECAUSE I had to deal with limited (8pin Outputs) number on the memory IC, I had to be 'smart' about it.
I linked 3 pins of the RAM to the RAM Decoder 74136 that in turn is controlling 7pins for ---column--- of the matrix. Then, the rest 5pins of the RAM chip, I linked directly to ---COUNT the lines--- of the matrix.
Also the Counter 7493 is counting to 7 (not to 5 as we made it in our first example). Im happy I get to this simple result, but I tried a TON of permutations, you probably understand. I hope is clear enough.
In short, I count the LINES from top to down 7 times, and I set the column bits per each count.
And I have the feeling my circuit and my logic here is exactly complementary to your circuit. Right? In my defense, I did whatever I could to make it work... and it is working., which is good. Right?

 

[marconi]

Now that you have clarified what I suspected may I suggest that you do not need to drive the 74138 by four data outputs of the RAM2732. Drive the 138 using the same 3 lines (1,2,4) of the 7493. This will still cause your display to be scanned line by line, top to bottom and then repeated. ie 7 lines

Now you have 8 data outputs. You can use the first 5 - D0 to D4 - of them to set the state of illumination state of each LED in a line. eg (00100) (010010) (10001) (10001) (11111) (10001) (10001) for the letter A

Now turn your attention to the address word which is 12 bits long A0 to A11. Use A0 to A2 (ie 1, 2 and 4) as now connected to the 7494 so that for any state of bits A3 to A11 the 7493 will cycle through 5 memory locations. These five memory locations are a unique group determined by bits A3 to A11. This means you can store in the RAM 2exp9 number of unique groups of 8 bit data outputs of which you will use 5 bits.

One could write the Address word A as ( A11, A10, A9......................A2, A1, A0) = (Character Identifier Address (9bits) Character Font Code Addresses(3bits))

The 7493 will always cycle through A2,A1 and A0 to output the 7 five bit line patterns of a character font. You only need to select which character font you want to display by setting the Character Identifier Address A11 to A3.

Thus letter A could have the Character Identifier Address 000 000 001 A2, A1, A0
Letter B could have 000 000 010 A2, A1, A0
Letter C ......000 000 011 A2, A1, A0
Letter D........000 000 100 A2, A1, A0

Thus by setting the Character Identifier Address you can pick a character to display. Of course you have to programme the five memory locations addressed by the Address Word A so that they contact the appropriate bit patterns for the seven lines which make it up.

 

[marconi]

Now that you have clarified what I suspected may I suggest that you do not need to drive the 74138 by four data outputs of the RAM2732. Drive the 138 using the same 3 lines (1,2,4) of the 7493. This will still cause your display to be scanned line by line, top to bottom and then repeated. ie 7 lines

Now you have 8 data outputs. You can use the first 5 - D0 to D4 - of them to set the state of illumination state of each LED in a line. eg (00100) (010010) (10001) (10001) (11111) (10001) (10001) for the letter A

Now turn your attention to the address word which is 12 bits long A0 to A11. Use A0 to A2 (ie 1, 2 and 4) as now connected to the 7494 so that for any state of bits A3 to A11 the 7493 will cycle through 7 memory locations. These 7 memory locations are a unique group determined by bits A3 to A11. This means you can store in the RAM 2exp9 number of unique groups of 8 bit data outputs of which you will use 5 bits for a line of 5 LEDs.

One could write the Address word A as ( A11, A10, A9......................A2, A1, A0) = (Character Identifier Address (9bits) Character Font Code Addresses(3bits))

The 7493 will always cycle through A2,A1 and A0 to output the 7 five bit line patterns of a character font. You only need to select which character font you want to display by setting the Character Identifier Address A11 to A3.

Thus letter A could have the Character Identifier Address 000 000 001 A2, A1, A0
Letter B could have 000 000 010 A2, A1, A0
Letter C ......000 000 011 A2, A1, A0
Letter D........000 000 100 A2, A1, A0

Thus by setting the Character Identifier Address you can pick a character to display. Of course you have to programme the seven memory locations addressed by the Address Word A - character identifier address in red- so that they contain the appropriate bit patterns for the seven lines which make up a character.

Slight correction inserted to text above.

 

[_q12x_]

...may I suggest that you do not need to drive the 74138 by four data outputs of the RAM2732. Drive the 138 using the same 3 lines (1,2,4) of the 7493. ...

This was truly very smart correction ! I didn't see it and I like it. I build it, tested and I confirm it works. Very logical !
- But for the rest of the explanation... uuuuggggh... I didnt understand from where I can switch the addresses. Please condense in another but very short and to the point explanation, more short than what you explained already (and I do appreciate the effort so far but I cant see any logic to follow). I read your text a couple of times with the circuit in the left, reading the circuit as well, but... really, I can not see any logical road to take. Try again, please.
- Also, in the same time I will try some more permutations, directly with the RAM chip, my usual testing way in the dark, until (IF) I find a result. I have an idea I wake up with, to try for testing.
And thank you so far.

 

[marconi]

I will try but not right now. What I will say though is that these technical problems, and our thinking about them, and coming up with possible solutions, and then testing them and learning from how they perform is how we learn profoundly.

I will show you in a video how I produce A and B when the ROM is addressed by the Gray codes 0000 and 0001.

(You know that this project including the use of the EEPROM is what the pupil I mentor and tutor had to solve himself - which he did with some explanations like I have provided you with - as a digital electronics project in his part-time Higher National Certificate Course (HNC) in electrical engineering. Thus, it is quite demanding so I would not beat yourself up if you find it difficult right now).