Question about "turning on computer" without a case.

[Red Squirrel]

Be careful about ground reference between different pieces of equipment too. Just make sure that if you take 5v from one place it's actually 5v at the other place. Ex: same ground reference.

Did that mistake with a solar charge controller. The minus from the solar panel was not the same as the minus from the power out. So trying to measure it or do anything with it ended up creating wacky results.

At this point I would just go the microcontroller route tbh. You could expand it to control the entire cabinet, such as select the game and do other things. You can easily set relay delays etc too. So 1 relay turns PSU on, waits 2 seconds, then another relay turns on and off to simulate hitting the power switch. It also gives you lot of flexibility on pretty much any other behaviour you want as you can just code it in. You could also have it control other aspects such as turn on cooling fans if the cabinet gets too hot, pretty much anything of that nature would be easy to do.

 

[purbeast0]

Be careful about ground reference between different pieces of equipment too. Just make sure that if you take 5v from one place it's actually 5v at the other place. Ex: same ground reference.

Did that mistake with a solar charge controller. The minus from the solar panel was not the same as the minus from the power out. So trying to measure it or do anything with it ended up creating wacky results.

At this point I would just go the microcontroller route tbh. You could expand it to control the entire cabinet, such as select the game and do other things. You can easily set relay delays etc too. So 1 relay turns PSU on, waits 2 seconds, then another relay turns on and off to simulate hitting the power switch. It also gives you lot of flexibility on pretty much any other behaviour you want as you can just code it in. You could also have it control other aspects such as turn on cooling fans if the cabinet gets too hot, pretty much anything of that nature would be easy to do.

I'm going to take ground and +5v straight from the PSU so it should be good. As for the microcontroller, at this point what you are describing is just overkill for what I need right now. If I ever go that route though that seems to make sense. The one thing you mention that could be useful though is adding fans at some point. However so far heat hasn't been an issue to my knowledge, and I don't have the cabinet on for long periods of time or anything so I'm not that concerned about it as of now.

 

[purbeast0]

@sdifox could the capacitor I got being a radial cap and not an electrolytic cap be part of the reason I was seeing the weird behavior where only ground would make the circuit close and not the +5v? Or is that the same thing?

I wired up the circuit earlier and tested it but didn't get results I wanted, but I think it might be because I cut the ground wire on my PSU to wire to the relay and never closed it again. Going to test it out later on after I close the ground loop on the PSU and see if the behavior changes. Had to pressure wash a bunch of shit today and didn't have more time to mess with it earlier.

 

[sdifox]

@sdifox could the capacitor I got being a radial cap and not an electrolytic cap be part of the reason I was seeing the weird behavior where only ground would make the circuit close and not the +5v? Or is that the same thing?

I wired up the circuit earlier and tested it but didn't get results I wanted, but I think it might be because I cut the ground wire on my PSU to wire to the relay and never closed it again. Going to test it out later on after I close the ground loop on the PSU and see if the behavior changes. Had to pressure wash a bunch of shit today and didn't have more time to mess with it earlier.

Eh, your mb has to be grounded or it won't work. Since it works, it must be grounded xd. Type of capacitor just have different characteristics, but they function the same way.

 

[purbeast0]

Eh, your mb has to be grounded or it won't work. Since it works, it must be grounded xd. Type of capacitor just have different characteristics, but they function the same way.

Well the ground wire that is messed up is on the daisy chain that I am using to power the circuit board so I was thinking it might have something to do with it though.

I did test the circuit board with the batteries and it worked as expected so everything is wired up right. I kept the LED light on there too even after wiring up the other pin2 output wire so I can see what it is doing even when connected to the PSU and motherboard.

I'll report back in a bit though after I test it out more

 

[sdifox]

Well the ground wire that is messed up is on the daisy chain that I am using to power the circuit board so I was thinking it might have something to do with it though.

I did test the circuit board with the batteries and it worked as expected so everything is wired up right. I kept the LED light on there too even after wiring up the other pin2 output wire so I can see what it is doing even when connected to the PSU and motherboard.

I'll report back in a bit though after I test it out more

Just use a different sata connector. You obviously need ground. I didn't understand you are using the one with the ground cut.

 

[purbeast0]

Just use a different sata connector. You obviously need ground. I didn't understand you are using the one with the ground cut.

Yeah the PSU has 2 "daisy" chains of HDD connectors. One I'm using for the HDD for the game, and the other one I just cut one of the ground wires to wire it to the relay, but I just left the other end of the cut wire hanging.

The HDD connector I tested it out with is before the ground wire is cut in the chain, and I did see the light come on but like I said it was doing weird stuff so I stopped trying it until I had time to complete the chain back.

 

[purbeast0]

Okay so here are the results. Looks like completing the ground chain did help as I'm not seeing the odd behavior I was prior.

For the sake of knowing what is going to what, the following pins are on the PWRSW

pin1 - PWR
pin2 - ground

And for the circuit you made, the "input" will be A and the "output" will be B.

When I first tried making pin1 go to A, without even hooking up pin2 to B, the red LED did not turn on. So like when I was testing, +5v wasn't opening the XOR for some reason. I then tried hooking up pin2 to B as well, and nothing hapened.

So I then tried hooking pin2 to A so that ground would be input like when I was testing with batteries, and nothing hooked to B, and the red light came on and then faded after like half a second.

I then added pin1 to B and turned it on. The red light stays on for half second but then it starts to basically "pulse" and comes on for a split second every .5 - 1 second or so. When I turn it on this way, the computer turns on, but then it shuts off, I'm guessing because it keeps acting as if the PWRSW keeps going on and off.

Any ideas why this could be happening when pin1 is hooked up as the "output"?

 

[sdifox]

Okay so here are the results. Looks like completing the ground chain did help as I'm not seeing the odd behavior I was prior.

For the sake of knowing what is going to what, the following pins are on the PWRSW

pin1 - PWR
pin2 - ground

And for the circuit you made, the "input" will be A and the "output" will be B.

When I first tried making pin1 go to A, without even hooking up pin2 to B, the red LED did not turn on. So like when I was testing, +5v wasn't opening the XOR for some reason. I then tried hooking up pin2 to B as well, and nothing hapened.

So I then tried hooking pin2 to A so that ground would be input like when I was testing with batteries, and nothing hooked to B, and the red light came on and then faded after like half a second.

I then added pin1 to B and turned it on. The red light stays on for half second but then it starts to basically "pulse" and comes on for a split second every .5 - 1 second or so. When I turn it on this way, the computer turns on, but then it shuts off, I'm guessing because it keeps acting as if the PWRSW keeps going on and off.

Any ideas why this could be happening when pin1 is hooked up as the "output"?

Can you take a pix of the board in your final config?

Pin 3 is the output of xor no? Why aren't you using that?

 

[purbeast0]

Can you take a pix of the board in your final config?

Pin 3 is the output of xor no? Why aren't you using that?

I am.

That is what the "output" is in my description up above. Yeah I know I didn't explain it properly lol.

pin1 and pin2 in my description above are the pins on the motherboard. Doesn't have to do with the XOR.

 

[purbeast0]

Forgot the images, here they are.

The connector with the HDD power adapter is what I am using for +5v and ground and I hook into one of the hard drive connectors to power/ground it.

And the other wires are what connect to the motherboard. Don't mind the black wire not being plugged in the pic, that was just when I took the pic.

 

[sdifox]

I need to see the backside of the board as well. I don't see how this can work if there are no connections on the back. I am assuming it is just a regular proto board with just holes ? Why a rpi hat proto board though?

 

[purbeast0]

I need to see the backside of the board as well. I don't see how this can work if there are no connections on the back. I am assuming it is just a regular proto board with just holes ? Why a rpi hat proto board though?

You can tell from the top what is connected. There are lines between the holes that are connected on the top. It's basically laid out just like a breadboard. There are no wires connecting anything on the bottom that I added, it's all just connected by the board.

Got that board cause it was the smallest/cheapest circuit board they had.

 

[sdifox]

You can tell from the top what is connected. There are lines between the holes that are connected on the top. It's basically laid out just like a breadboard. There are no wires connecting anything on the bottom that I added, it's all just connected by the board.

Got that board cause it was the smallest/cheapest circuit board they had.

What will it do if you connect pin 2 of the xor input to +5V? No need to solder, just tape it.

I still think you need to relay the discharge branch. Right now it doesn't look like the xor is doing anything since you have only one input. It is just capacitor filling and draining.

 

[purbeast0]

What will it do if you connect pin 2 of the xor input to +5V? No need to solder, just tape it.

I still think you need to relay the discharge branch. Right now it doesn't look like the xor is doing anything since you have only one input. It is just capacitor filling and draining.

I just tried this out now and when I do this it acts the same as my prior results, except I have pin1 and pin2 swapped around to get it to behave that way.

So what I mean is, I have pin1 PWR connected as the input A, and pin2 ground connected as output B, and when I do this, the light comes on for 1/2 sec and goes off, and then it pulses, like it keeps running the circuit in an infinite loop or something, and that the light blinking for a split second is just because the capacitor isn't fully discharged as it runs over and over.

If I don't have pin2 ground connected as output B, it works just as expected where it only blinks once and stops.

And remember, pin1 and pin2 I am referring to here are not the XOR gate they are the pins on the motherboard.

 

[sdifox]

I just tried this out now and when I do this it acts the same as my prior results, except I have pin1 and pin2 swapped around to get it to behave that way.

So what I mean is, I have pin1 PWR connected as the input A, and pin2 ground connected as output B, and when I do this, the light comes on for 1/2 sec and goes off, and then it pulses, like it keeps running the circuit in an infinite loop or something, and that the light blinking for a split second is just because the capacitor isn't fully discharged as it runs over and over.

If I don't have pin2 ground connected as output B, it works just as expected where it only blinks once and stops.

And remember, pin1 and pin2 I am referring to here are not the XOR gate they are the pins on the motherboard.

Yeah that is why I wanted to use the transistor to stop the blinking, but since I messed up the type that is that. The whole point is to to get that signal from A to B for a second once and no more. The idea of putting the resitor before the capacitor on XOR input 1 was to slow down that input... but you are saying that makes no difference. Serious ego bruiser lol

 

[purbeast0]

Yeah that is why I wanted to use the transistor to stop the blinking, but since I messed up the type that is that. The whole point is to to get that signal from A to B for a second once and no more. The idea of putting the resitor before the capacitor on XOR input 1 was to slow down that input... but you are saying that makes no difference. Serious ego bruiser lol

I didn't put any resistor before the capacitor on the XOR input 1 I don't think.

But I am not understanding why it makes a difference when using batteries as the power/ground and it doesn't keep repeating the blinking, but when I do it in the cabinet it does.

Also, are you like 100% positive putting the NPN transistor into the circuit will work? Or I guess I should say - how confident are you? I could always run and grab one.

 

[sdifox]

I didn't put any resistor before the capacitor on the XOR input 1 I don't think.

But I am not understanding why it makes a difference when using batteries as the power/ground and it doesn't keep repeating the blinking, but when I do it in the cabinet it does.

Also, are you like 100% positive putting the NPN transistor into the circuit will work? Or I guess I should say - how confident are you? I could always run and grab one.

yeah that behaviour is wonky.

before you run out to get more parts, I got a question, did you wire that capacitor in reverse? as in negative is wired to +5?

resistor + capacitor was supposed to induce a delay. so input 1 of XOR gets 5V right away and input 2 of XOR a second later, giving you that on for a bit then off you needed. Try that first.

The RC Delay Element - Build Electronic Circuits

The RC delay element is a way to create a time delay in your circuit by connecting a resistor and a capacitor.

www.build-electronic-circuits.com

 

[purbeast0]

yeah that behaviour is wonky.

before you run out to get more parts, I got a question, did you wire that capacitor in reverse? as in negative is wired to +5?

Yes, negative is wired to +5v. Is that wrong? And I could try flip flopping it too. Not a big deal.

I thought I remembered you saying something about having negative side on the wire when I was using the breadboard.

EDIT:

Okay I see your edits. So is the resistor inline or parallel? Like if I add one does it go input -> resistor -> cap -> XOR pin1?

Right now there is a resistor hooked up to the second pin of the capacitor that is on the XOR pin1. Doing that is what got it to work initially on the breadboard. Without that it wasn't lighting up.

 

[sdifox]

Yes, negative is wired to +5v. Is that wrong? And I could try flip flopping it too. Not a big deal.

I thought I remembered you saying something about having negative side on the wire when I was using the breadboard.

EDIT:

Okay I see your edits. So is the resistor inline or parallel? Like if I add one does it go input -> resistor -> cap -> XOR pin1?

Right now there is a resistor hooked up to the second pin of the capacitor that is on the XOR pin1. Doing that is what got it to work initially on the breadboard. Without that it wasn't lighting up.

give this a shot. PWRPin and GNDPin are the ones on your jumper wire.

 

[purbeast0]

give this a shot. PWRPin and GNDPin are the ones on your jumper wire.

View attachment 22624

Okay thanks. I will try that out a bit later. I have more pressure washing to do today.

That looks very similar to what I have except the resistor is before the capacitor, right?

Also, I'm still not sure what polarity to use with capacitors since it's just 2 straight lines. Does that mean it doesn't matter? Or when it is that way, does that always mean like neg/pos first and the other second?

 

[sdifox]

Okay thanks. I will try that out a bit later. I have more pressure washing to do today.

That looks very similar to what I have except the resistor is before the capacitor, right?

Also, I'm still not sure what polarity to use with capacitors since it's just 2 straight lines. Does that mean it doesn't matter? Or when it is that way, does that always mean like neg/pos first and the other second?

If you look at the capacitor, most of it is black except one silver stripe down the side with what looks like stop signs. That pin is the negative. It gets power from the + side and put out power from - side once it charges sufficiently. That is what we are trying to use to slow down the signal reaching xor on the second pin.

 

[purbeast0]

If you look at the capacitor, most of it is black except one silver stripe down the side with what looks like stop signs. That pin is the negative. It gets power from the + side and put out power from - side once it charges sufficiently. That is what we are trying to use to slow down the signal reaching xor on the second pin.

Okay gotcha. Well the way it's wired up now the power is definitely going to the negative side and putting powre out from the positive side. You think it's worth me changing it around before doing anything else?

Also, is that a general thing with capacitors? The only thing I know about them is that the polarity matters and I've replaced all of the caps on my arcade monitor. But I just followed a guide and what as labeled on the board. And I know that the shorter wire is always negative.

 

[sdifox]

Okay gotcha. Well the way it's wired up now the power is definitely going to the negative side and putting powre out from the positive side. You think it's worth me changing it around before doing anything else?

Also, is that a general thing with capacitors? The only thing I know about them is that the polarity matters and I've replaced all of the caps on my arcade monitor. But I just followed a guide and what as labeled on the board. And I know that the shorter wire is always negative.

Yeah you should flip the polarity of the cap. you may have damaged it. But then if you didn't hear it pop, you might be ok.

 

[purbeast0]

I flipped the cap on the first circuit and nothing changed. Still had the pulsing light.

I just redid it to the one you have up above and nothing happens at all. No light or anything. Here is a pic.

The other cap pin (negative) is on the ground you just can't see it cause the pic angle. I don't have much leg left since I snapped them on the first circuit after soldering em.