kludge’s TF530 build

[kludge]

Morning Kludge, had a chance to do look into the board yet? Any signs of life?

Morning? It’s 5 pm here

Just getting home from work. Will try to look into it tonight. First priority: see if I have any output from the oscillator. Might hook up the oscilloscope and start poking around to see if there’s any activity anywhere.

[PaulJ]

Morning Kludge, had a chance to do look into the board yet? Any signs of life?

Morning? It’s 5 pm here

Just getting home from work. Will try to look into it tonight. First priority: see if I have any output from the oscillator. Might hook up the oscilloscope and start poking around to see if there’s any activity anywhere.

Yes, there's a definite time shift.. just have trouble says good evening when its morning here..

[kludge]

Yes, there's a definite time shift.. just have trouble says good evening when its morning here..

I’m having trouble saying “good morning” because... Well, just because

[kludge]

Does this look weird to you as the output of the oscillator on JP1?

(Admitting to being stupid: I had the oscillator turned the wrong way round :facepalm:)

Still doesn’t work. I might have fried something

F3E20CEB-3E9E-4422-AB64-B9C74D7EE480.jpeg (165.88 KiB) Viewed 4861 times

[kludge]

I have exactly nothing on CLKOUT on IC5...

MEDIC!

[kludge]

Do I have a bad oscillator or a bad IC5? Or both? Or neither?

Could the oscillator be the wrong kind? Or did I damage it when i mounted it the wrong way (omg I'm worthless )?

[Maximilian]

Haven't played around with this for a long time but lets give it a go until someone else comes along that knows his or her stuff.

You would expect a more square wave out of the oscillator....

Questions:
1. Do you have a x10 setting on your probe?, does the output of the oscillator or the buffer look better then?
2. What is the Vmax out of the oscillator adjusting for the scope and probe settings?
3. Do you have a datasheet on the oscillator you bought?
4. Did you get the exact same buffer as stated?
5. Do you have another device with a crystal you can test(and also the operation of the device while measuring)
6. Did you get your grond connection close to the oscillator?
7. Is the output of the oscillator or the buffer shorted to ground?

I really do not see how a bad oscillator installation would kill the buffer, if VoutHigh of the oscillator is higher then the Vt+ of the buffer and the VoutLow of the oscillator is lower then the Vt- of the buffer (with the correct Vcc ofcourse) the buffer should give an output.

[kludge]

Haven't played around with this for a long time but lets give it a go until someone else comes along that knows his or her stuff.

I'll take it!

You would expect a more square wave out of the oscillator....

Yeah, the 7 MHz clock looks much cleaner, even if it overshoots some.

1. Do you have a x10 setting on your probe?, does the output of the oscillator or the buffer look better then?

Yep. Will try that.

2. What is the Vmax out of the oscillator adjusting for the scope and probe settings?

Not sure I understand that. You mean what voltage the peaks are at in the current waveform? They seem to be at around 1,5 V, which is weird.

3. Do you have a datasheet on the oscillator you bought?
4. Did you get the exact same buffer as stated?

I didn't order the parts. I got them as a gift from someone who bought to and didn't get around to building one of them. I don't think he completed the first one either.

5. Do you have another device with a crystal you can test(and also the operation of the device while measuring)

I went through my pile of junk looking for something that I could get a 25 MHz signal from, but I didn't find anything.

6. Did you get your grond connection close to the oscillator?

Quite close, at the JTAG connector.

7. Is the output of the oscillator or the buffer shorted to ground?

I'm a bit ashamed to say that I didn't check for shorts. Yet

I really do not see how a bad oscillator installation would kill the buffer, if VoutHigh of the oscillator is higher then the Vt+ of the buffer and the VoutLow of the oscillator is lower then the Vt- of the buffer (with the correct Vcc ofcourse) the buffer should give an output.

I might just order new buffers and a new oscillator to rule them out. It's not like they're very expensive.

Thanks for your suggestions! It's almost midnight here, so I'll get back to this tomorrow. Hopefully

[Maximilian]

Yeah, the 7 MHz clock looks much cleaner, even if it overshoots some.

Try the X10 setting on the probe, rest should be ok.

Not sure I understand that. You mean what voltage the peaks are at in the current waveform? They seem to be at around 1,5 V, which is weird.

If i'm correct you should see a oscillator high voltage output of about 90-100% of VCC or 2,8V-3,3v, the low voltage should be around 0-10% of VCC or 0-0,33V, this is dependent of the type of oscillator of course.

The buffer output should go high if the input goes from below 1v to more than 2v, it should go low if the input goes from more than 2v to a voltage lower than 1v, if you have the correct buffer.

I didn't order the parts. I got them as a gift from someone who bought to and didn't get around to building one of them. I don't think he completed the first one either.

Could also be the wrong parts…

I went through my pile of junk looking for something that I could get a 25 MHz signal from, but I didn't find anything.

It was just to test your Scope setup, not as a replacement for your TF530.
Just try the 28Mhz crystal on the a500 mainboard, in most cases it should be available at FB101 near the oscillator.

I might just order new buffers and a new oscillator to rule them out. It's not like they're very expensive.

On your own risk:
Personally i would remove the oscillator and use a 10K resistor to switch the buffer input between 3,3v and gnd while not touching the conductors and using short wires, the output from the buffer should respond nicely.

Spares are always nice to have, and that way you have some for your TF534 build
Good luck!

[kludge]

On your own risk:
Personally i would remove the oscillator and use a 10K resistor to switch the buffer input between 3,3v and gnd while not touching the conductors and using short wires, the output from the buffer should respond nicely.

Sounds like a plan! I probably won’t even have to remove the oscillator as long as I remove the jumper at JP1. But we’ll see.

Good luck!

Thank you!