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.

 

[marconi]

London calling - what news from Romania please? I would like to see you spell out 'Romania' or your name or moniker on the 7x5.

 

[_q12x_]

I was quite busy actually, I had to repair the tip of my iron soldering, I had to make a movie with all the progress I did so far on the led matrix code speed, in arduino and its library functions, and only from this point forward I can concentrate on the simulation. I did some research to figure out how to simulate RAM chips in proteus, because is not simple, and I did find a solution and I have to test it out. I will update you soon. Remember that for you is easy because you have experience with these things, but for me is the first time (for some part of it) thats why it takes awhile.
And I already buy your 74LS138 Decoder/Demultiplexer IC..from aliexpres. It will arrive in maximum 2 months (if im lucky).

 

[_q12x_]

 

[marconi]

Brilliant work! Your earlier hesitancy was unfounded. As I suspected, you pick things up quickly.

Next step is to use the ROM to store the five 7 bit words which describe the fonts of the alphanumerics you want to use.

I used this as my font reference but you could design your own perhaps:

5x7 DOT Matrix - https://fontstruct.com/fontstructions/show/847768/5x7_dot_matrix

I have two eeproms left - would you like me to send you one?

http://cva.stanford.edu/classes/cs99s/datasheets/at28c16.pdf

PS1: LED current limiting resistors?
PS2: Base resistors for 7 x Row transistors?
PS3: Base resistors for 5 x Column transistors?

 

[marconi]

q12X My next project is the modernise and make more reliable the remotely controlled door lock my wife uses to let her nurses and cleaning ladies in each day. I bought over a year ago(! - I lack your motivation) some RF Solutions radio frequency key fobs and receivers boards which I need to turn into a working system. I think it was these items - need too search them out.

BRAVO-T 8 CHANNEL TRANSCEIVER TELEMETRY MODULE 1000M - https://www.rfsolutions.co.uk/radio-modules-c10/bravo-t-8-channel-transceiver-telemetry-module-1000m-p378

FOBBER 1 CHANNEL ON/OFF BUTTON, UP TO 200M, 868MHz KEY FOB TRANSMITTER - https://www.rfsolutions.co.uk/remote-control-systems-c9/fobber-key-fobs-transmitter-c204/fobber-868mhz-key-fob-c206/fobber-1-channel-on-off-button-up-to-200m-868mhz-key-fob-transmitter-p760

 

[_q12x_]

hello mister @marconi,
I still can not see a way to create any shape/character on this matrix display.
Can you detail more from here? I really dont see it. As I mentioned in the movie as well.

Brilliant work! Your earlier hesitancy was unfounded. As I suspected, you pick things up quickly.

Im still hesitant at this moment as well. I pick things if I can follow a logic. But right now is 0 in my mind.

I have two eeproms left - would you like me to send you one?

Yes. But please dont make a BIG box for it, since these mail monkeys here in my town, are looking directly to the size of the package, and then to it's weight. And they tax plentifully if is over-sized or over-weight. My suggestion and please do exactly as Im telling you, put this IC into a simple envelope, the smaller the better. Like this is perfect : (trust me)

Don't even think to put into a colored envelope because that is also "too fancy" and the monkeys here, also tax the hell out of me. Also from your perspective you will pay something like 1 pound or close to it. I didnt check out how UK are taxing small envelope mail delivery. It might be free for you. Who knows. But I guarantee it will be very cheap. It will be as you are sending me an old fashion card in an envelope.
You most probably will have to bent OUTSIDE the legs of the IC , to be in line with the IC and not to poke the envelope paper if left unbent. You can also put some cardboard on the pins , poke the pointy legs into a small, cut to size cardboard, for a small increased protection.

I will resend you my mail address in private.
And thank you for it ! You are very cool.

I bought over a year ago(! - I lack your motivation) some RF Solutions radio frequency key fobs and receivers boards which I need to turn into a working system. I think it was these items - need too search them out.

Well, look on them and BE SURE are these devices from your links. And not some other brand or #id.
Do it now.
On the link page you give me, I find a video presentation on youtube:

They are describing this RF board very well, in a clear UK accent, haha, and they seem exceptionally easy to implement. They show the pin diagram connections to +3V and 0V for both MODES of this board that can be a receiver OR a transmitter depends how you wire those pins. VERY easy and straight forward. It appears that has a LEARNING button on the receiver side. So you might be very much in luck to press that learning button, press your remote button, and wait for it to learn the signal, and thats it, that simple. After that will 'recognise' your specific RF from that little remote. You can play with other RF transmitting devices. Your TV remote is transmitting in infrared so it will not work(unless this board has an IR receiver as well), and it is directional anyway and limited range. So it might be RF only what you have there.
I find this board datasheet >>> https://docs.rs-online.com/6486/0900766b813bbdc3.pdf
- Read it -
And I made for you it's pin connections more clear to follow

This board works at 3V, designed to be supplied from a 2x1.5V batteries (as a transmitter) but also as a receiver, same power supply.

So, in your case, I will use a transformer, even a mobile charger will be fine at 12V, 9V, 5V, whatever. Also >500mA. Like this one:

then a variable voltage regulator like LM317 or AMS1117(smd), and wire it for 3V output and power your Receiver board (in your case).
This is how I would do it. VERY SIMPLE project !!! You can make it in 1 day, top to bottom.
Also I want pictures and movie with it installed and working until tomorrow morning !

 

[_q12x_]

Ive just made a test right now and you may have to put some sewing thread/string on top because these small cardboards may fly on vibration. If you secure them with a piece of sewing string it should be more than fine. Here are my test pictures:

 

[marconi]

We both have a 555 clock. I thought you might like to see my 7x5 when I reduce my clock to 1 Hz for a while and then return it to 1kHz. You can see how the column leds change to construct the letter A and what the eye and brain observed when the clock rate is increased.

 

[_q12x_]

I still can not see a way to create any shape/character on this matrix display with the circuit I have so far.
Can you detail more from here? I really dont see it. As I mentioned in the movie as well.

 

[marconi]

If you had five 7 bit memory locations which you could address/read using the 3 bit code the 7493 generates as it counts in binary from 0000 to 0100 then you can use this scheme to select a 7 bit memory location which contains the data to turn on the required leds in a column, column by column as my video shows. Then you speed it up.

What I would like you to see for yourself is how much in the design of digital electronics is about stringing/sequencing many very simple elemental actions/processes very quickly to generate what is wanted.

 

[_q12x_]

so... what you are saying... to link directly the counter 7493 to this memory chip and increment each of it's data stored inside ? Like this?
And 74138 decoder is not needed at all in this case, right?
And from D0-D7 of this memory might be the outputs to link to the matrix... right?

 

[marconi]

That is largely correct. You still need the 74138 to switch the columns on in turn when driven by the same 1, 2, 4 outputs of the 7493. You could construct some combinational logic but that would be long winded.

Of course you could do the work of the 74138 and the eeprom in software and then feed the 5 bit 'one of 5' column word and the 7 bit row/line data word to the 16 bit outputs of the MCP23017. You then connect these outputs to the circuitry you have designed in proteus.

 

[_q12x_]

Good news:
Memory #1
I figured out how to manually program a (simpler) RAM in my simulator, thanks to youtube and a couple of google searches, staying late last night. This was the easiest.
The most important thing for me, is repetition. If I am not repeating some new stuff enough multiple times, I forget it's head and its end in a very short time. If I make it a routine, for awhile, it is impregnating in my brain and I hardly forget it. I moved relatively quickly with these RAM chips now, because I did these things some years ago, once or twice, but not doing it again consistently or repeatedly, I forget everything. Well, something remained because I moved and recognized relatively easy now what to concentrate over and I work it out somewhat fast. But I helped myself from youtube as I said. Im happy I managed to make it work in the end.
I still have problems writing and loading a *.bin or a *.hex file into the simulation chip. THe content of these files is a mystery for me. I dont think I ever did it like this. So this is brand new and very important to figure out. So far I had no luck. If anyone who is reading these things know how to do it, please advise me. I will ask on other forums as well.

 

[_q12x_]

Memory #2
This one was a bit tricky, and I had to look more closely into it's datasheet. And I managed to make it work. It has a bit more complicated way of MANUAL programming, I changed and play with those links there and you have to switch both of them to program and read the chip. Thats the conclusion I got it work.

 

[_q12x_]

Memory #3
This was a fail in implementation but I understood what it needs to make it work. It is by far the strangest RAM I ever encountered for manual programming.

this simulation didnt work because that pulse circuit didnt want to work at all, probably some program bug or a mistake I made but im blind to see it; so I probably have to make a 555 circuit for it. And if that doesnt work, at least I tried. Heh. Its not the circuit fault its the simulator fault this time. Sometimes I personally get SF issues from programs, because I dont know each detail of the behavior of the program. Oh well....

 

[_q12x_]

All that was last night.
But from now on, like I said and I am repeating for clarity, I have to concentrate on loading a *.bin or a *.hex file into the simulation chip. The content of these files is a mystery for me. So this is brand new and very important to figure out. So far I had no luck. If anyone who is reading these things know how to do it, please advise me. I will ask on other forums as well.
So this is the next step I will concentrate from now.
Pretty hard if you ask me.... hard to figure out how to make it work.

 

[marconi]

How are you generating the program pulse which must be more than 45 but less than 55 mS?

 

[_q12x_]

I explained this already:
I tried this circuit but for some reason Proteus simulator didnt like it and didnt run it. The capacitor didnt charged up. I will have to try with a 555 circuit, replacing this simpler one.

 

[marconi]

Try this simple circuit with R as 1kR and C as 50 microF

Or R as 5kR and C as 10micF.

In both cases time constant t = R x C = 50mS

If negative pulse required then use simple circuit below. If positive pulse required then invert using transistor or NOT logic gate.

 

[marconi]

I explained this already:
I tried this circuit but for some reason Proteus simulator didnt like it and didnt run it. The capacitor didnt charged up. I will have to try with a 555 circuit, replacing this simpler one.
View attachment 100972

This circuit will not produce the required pulse shape and duration. I do not have time right now to explain why. It is to do with how the push button is wired in and RC time constant is only 10mS = 1KR x 10micF which is less than minimum 45mS.

 

[_q12x_]

nope , not good. I tested in other simulator that circuit with the transistor, which very much resembles your much simpler version and I applaud its simplicity, I like it very much actually, more than mine.
But the problem with both circuits here is that Pressed button !!! As long as I am keeping it pressed, it will "count" 0V ! Which is not good. So if im counting 10s with the button pressed down to 0V, the circuit will stay to 0V 10s. WHen I release the button, it will count another extra 50ms based on the cap and res values that I chose and reach 5V. So this behavior is NO BUENO !
What I really need is like this: Press ONCE the button and keep it pressed. But the circuit will not stay at 0V. It will jump from 5V to 0V in the moment the button made the contact, count internally those 50ms, and rise up to 5V by itself, while my button is still pressed. When I release the button from its contacts, the circuit still remains at 5V, unchanged. Only when I press the button again. and at the very first contact , the whole logic repeats again. Clear now?
I am trusting the good old 555 timer to do it. But... I didnt actually stay down to think about it. I only figure out how the logic should be, the one I just described so far.
Remember this is waaaay a SIDE mini-project or dare. Haha. Not at all the main quest Im in. Its a cute side quest. A curiosity.

 

[marconi]

Please draw me the circuit you have connected to the CEbar pin.

 

[_q12x_]

Good day sir, Mister @marconi and others that are reading my thread, please read this page --HERE-- I put it in discussion last night but unfortunately the guys that are answering me are too undecided. Usually they are of great help but here, in this case, this specific subject is like a black cat for them. They keep some inexplicable distance.
Its not that long, is 1page and a half of reading, until that big blue screen screenshot of mine. And you can skip many unimportant points. See if it is ringing a bell for you and help me progress and push this "programming a RAM chip with an external file" to its final conclusion.
Thank you in advance!

 

[_q12x_]

Please draw me the circuit you have connected to the CEbar pin.

you mean this one? Yours is better ! ...but both inutilizable.
we must think on another BETTER circuit. This is NO BUENO.

 

[marconi]

Please answer my question. SHow me exactly how you modelled my circuit and actually connected it to CEbar. Did you pass the pulse from my circuit through those relay contacts ? Did you do as in the attachment?

S1 is is NO pushbutton for programming. S2 is the NO switch to tell the chip to operate as a RAM ie programming over. When in programming mode S2 must be open. You know already what to do with the OEbar pin for programming mode and RAM mode.

 

[_q12x_]

This is the last circuit I made following your instructions.
I am now pretty sure how to connect the RAM chip in the next stage. No worries.
I made some very interesting advancements from 2 days in a row until today, about how to manually program a RAM. I start to get it, and also how to program a RAM from a file, which is very important.
I did not used the RAM or any relay in this last circuit. That RAM is floating there.

 

[marconi]

Have you run this circuit in proteus?

 

[_q12x_]

Have you run this circuit in proteus?

yes

 

[marconi]

I deserve better than ‘yes’.

 

[_q12x_]

I deserve better than ‘yes’.

Check my answer in #93 ...also your immediate answer next in #94
I was completely concentrated these last 2 days, full days actually, on the loading an external file into the RAM in Proteus simulator and tonight, some minutes ago we reach the salvation conclusion. Now I can load any external file as long it is not very complicated because the editor is very old and is not that nice to edit with it, but it is doing an excellent job, and that is all that matters. I will still have to research into more modern .bin editors, so there is more to push. We have progress.