PI5 from ITMD

[raygdunn]

Hi Polymer,

The PI-5 does work, I've still got it on a breadboard here (less some peripheral wiring removed for use with a Barracuda board ☺ ). However I did find sensitivity very much less than the PI-1 in my case and focussed on that one instead. Maybe it just needed some tweaking...


(The schematic must either be the major revision emailed by Qiaozhi, earlier in this thread, or the corrected version in the revision 2 print of the book, if it's out yet)


Ray

[Polymer]

Hi Raygdunn,

Thanks for your positive feedback on the PI5!

I'm more interested in the audio part of the PI5 than in the sensitivity.
How is the sound reaction of the PI5 for you? Do you like it?

Perhaps there somehow is a way to make differences in decay times audible with simple techniques.

Cheerio, Polymer

[bernte_one]

here is the sprint file
feel free to modify
3.zip

the are changes to made, look some postings before

[6666]

Hi Polymer,

The PI-5 does work, I've still got it on a breadboard here (less some peripheral wiring removed for use with a Barracuda board ☺ ). However I did find sensitivity very much less than the PI-1 in my case and focussed on that one instead. Maybe it just needed some tweaking...




(The schematic must either be the major revision emailed by Qiaozhi, earlier in this thread, or the corrected version in the revision 2 print of the book, if it's out yet)


Ray

Ray did you make the headphone version or the speaker version ?
What battery voltage did you use ?

[Polymer]

I have started to work my way through the schematic to put it onto a stripboard and came across what might be an error.
It's the left side of the 555 timer pin 7, 6 & 2 the setup appears different. These schematics are from this thread. I don't know which one came from Qiaozhi per mail, yes I got my files mixed up

So which one would be the right one?

@raygdunn: which schematic did you use?

cheerio and thank you

[DOOLEY]

hello polymer,

had a quick look at your 2 pics,

the one on the left with the green lines,
the 12k is feeding pin 6, should be pin 7,
going to suspect (pretty sure really) the left hand pic wont even "RUN" !!!


right hand pic looks better.........

[Qiaozhi]

I have started to work my way through the schematic to put it onto a stripboard and came across what might be an error.
It's the left side of the 555 timer pin 7, 6 & 2 the setup appears different. These schematics are from this thread. I don't know which one came from Qiaozhi per mail, yes I got my files mixed up

So which one would be the right one?

@raygdunn: which schematic did you use?

cheerio and thank you

[ATTACH]35180[/ATTACH]

I don't know where the left-hand schematic is from, but it's not one of mine.
Clearly there is a wiring error there.
The right-hand schematic is the correct one.

[Polymer]

Thanks for your replies!

No worries Qiaozhi, the left-hand schematic is not from you

I got the left sided schematic from post #46.

@geoscash
This might the cause of the problem you've been having with your build.

[raygdunn]

Hi Raygdunn,

Thanks for your positive feedback on the PI5!

I'm more interested in the audio part of the PI5 than in the sensitivity.
How is the sound reaction of the PI5 for you? Do you like it?

Perhaps there somehow is a way to make differences in decay times audible with simple techniques.

Cheerio, Polymer

Hi Polymer,
Sorry this reply is so late. I've only just found the posts.
From what I remember, it's the regular harsh square wave beep.

The book designs are there to be played with☺ If I remember, it's been a while, I think this microprocessor was near its storage limit.

(I'd like to get into the programming side sometime, but it's picking one to learn about, probably needs to be a 32 bit. I have an STM32L0536-DISCO board, which proved to be a bad choice. Low power, includes a display, buttons LEDs etc. Sounds great, but software not pleasant and all the ADC connection seemed to be used for the demo facilities, so didn't get anywhere useful. Also the ePaper display, whilst permanent display until updated, takes a second or more to update)

Ray

[raygdunn]

PI-5

Ray did you make the headphone version or the speaker version ?
What battery voltage did you use ?

I used my usual old Sony headset. Wired in Serial for about 68ohm total resistance. I'm fairly sure l read somewhere, probably the book, that the voltage should not exceed 9V.

Ray

[geoscash1]

Back at it!

Ok,

after a brief hiatus from this stuff I am going to get back on this and try to figure out what to do. I think my redraw of the schematic on pin 6/7 of the 555 is the problem like you guys mentioned above so that is where my focus will be in the track down of the issue.

I have been away for a bit because I am now battling a new health issue, cancer of the colon, I just had surgery (removed 16 inches of my upper colon, had a tumor the size of an apple in there) and am in the healing process before moving to the next phase of repairing myself.

Anxious to get working on this since I will have some home time to mess around with it....

Here is a pic of the pcb with what I think is where the correction needs to be?

[raygdunn]

Ok,

after a brief hiatus from this stuff I am going to get back on this and try to figure out what to do. I think my redraw of the schematic on pin 6/7 of the 555 is the problem like you guys mentioned above so that is where my focus will be in the track down of the issue.

I have been away for a bit because I am now battling a new health issue, cancer of the colon, I just had surgery (removed 16 inches of my upper colon, had a tumor the size of an apple in there) and am in the healing process before moving to the next phase of repairing myself.

Anxious to get working on this since I will have some home time to mess around with it....

Here is a pic of the pcb with what I think is where the correction needs to be?
[ATTACH]37290[/ATTACH]

Hi geoscash1,

I don't think this is the bug you are looking for. The connections that you want for the 555 is Q's, the one on the right in his earlier posting above. Pins 6 and 7 look correct on your PCB image, without change, I think.

I breadboarded mine some time back, so wouldn't have encountered the problem.

So sorry to hear of your problem. I hope that I won't be following in your footsteps. I'm in in the queue (6 month waiting list!) for a colonoscopy at the moment. God what it is to get old...

Ray

[geoscash1]

Hi geoscash1,

I don't think this is the bug you are looking for. The connections that you want for the 555 is Q's, the one on the right in his earlier posting above. Pins 6 and 7 look correct on your PCB image, without change, I think.

I breadboarded mine some time back, so wouldn't have encountered the problem.

So sorry to hear of your problem. I hope that I won't be following in your footsteps. I'm in in the queue (6 month waiting list!) for a colonoscopy at the moment. God what it is to get old...

Ray

Hey thanks Ray, I'll keep a prayer out for you as well. I think it is all the processed foods these days that is killing us all. time to get back to gardening real food.

Ok, back on the topic, I thought the problem was the connection from the 12k (r19 original/r11 my redraw) to pin 6 needing to be feeding pin 7 to be correct. But now that you mention it, I remember my issue was the 3904 and R17 (redraw) (10 ohm resistor) were burning up. so maybe the issue is with the wiring on the other 555. I'll have to regroup and look this all over agian to refresh my memory and get the schematic back in my mind to figure it out.

I had a friend redraw the circuit to pdf and make the pcb for me so I have the redrawn schematic and pcb image, I'll dig them out and maybe you guys can look them over with a fine tooth comb and see if you can spot any other mistakes I may have missed.

Thanks for the help on this, I reall think this design has potential and it has stuck with me since I first saw it so I really want to get it working.

Geo

[geoscash1]

I circled where I think the issue lies, but am not totally sure. maybe the pinout of the 2N3904? or its connections. I have looked it over a thousand times but am not seeing the problem.

Any other eyes out there that can spot the issue. This circuit is burning up the 3904 and R17 the 10R resistor.

[raygdunn]

I circled where I think the issue lies, but am not totally sure. maybe the pinout of the 2N3904? or its connections. I have looked it over a thousand times but am not seeing the problem.

Any other eyes out there that can spot the issue. This circuit is burning up the 3904 and R17 the 10R resistor.

[ATTACH]37296[/ATTACH]

Hi,

I may have the answer, but I really am not that good at comparing PCB and differently numbered schema☺

The connections to your 555 seem to match my final schema (emailed by Q). However there is the bit on the right of my schema showing the headphones wiring and separated out the alternative with 3904 amplifying transistor to a speaker.

As I read the connections, there is still a 5K pot. that shouldn't be there, left over from the headset components. This is pulling the voltage going into the 3904 positive and switching it fully on. Hence your problem with the 10ohm resistor smoking (may have damaged speaker too). So remove the 5K pot. and hopefully...

It's the sort of problem you just wouldn't be looking for...

I hope that makes some sort of sense.

Ray