Break contact switch / audio player - Can't find components

SamR

Joined Mar 19, 2019
5,031
I have one in front of me but I havn't played with it yet. Instead of the transitor switch just use the micro switch. It has both NO and NC switches so you have all the bases covered. On the corner is a double row of pins and 2 jumpers. VCC, GND, FT, P-L, P-E, REC marked next to the pins. Power it up from the battery to VCC+ and GND-. Push the REC red button to record using the onboard mic and play it back on ether the playe or playl button. I suspect the playL is maybe the loop button that will repeat the playback as long as the button is pressed. Once it is recorded and working you will have to experiment a bit shorting out the pins until you find the playback combination. VCC to pin? I would expect that to be what to start with. Maybe someone here has actually used one.
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
It looks like PlayE is the option I want.

So the microswitch sits between the pins? In which case, it must have to be be VCC and PlayE (assuming it is PlayE i want) because they'd be the only bit of the circuit board used other than the outgoing connection to the battery on GND, right? Does the microswitch just clip on, or is it a solder job?
 

SamR

Joined Mar 19, 2019
5,031
On the back of the switch are 3 pins, common, NO, NC. The pins appear to be stake on pins but can be soldered to. 2 holes thru the switch for screw mounting. Use NC and common so swich is open when cabinet door closed and makes contact for open door. VCC on the board and most likely playE for single play or playL for continuous play as long as door is open. As long as the door is open the contact will be pulling power so leaving door open will drain battery. I would put the microswitch on the hinge side of the door and adjust as needed. Maybe along the top edge of the cabinet opening out of the way.
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
Okay, so:

Coin Battery Holder (with Battery) - presumably the +ve line > Magnetic Reed Switch > VCC > Common on Microswitch > NC on Microswitch > PlayE pin > Current travelling through the ISD1820 board > GND > coin battery holder - -ve line?

What sort of power drain is a circuit like this on a coin battery? Admittedly the door will be shut most the time, but just so I know.

I might be misunderstanding, but would the microswitch be somehow separate from everything else - I thought it just shorted across some of the pins on the board. My current plan is to put the magnetic reed switch on the reverse side of the door (which isn't the hinge side, but is out of view), with the wired side on the top of the frame and just mount the circuitry next to it on the inside wall of the cupboard (Again, out the way)
 

SamR

Joined Mar 19, 2019
5,031
Battery to VCC and GND, Switch to GND and playE? There are 12 pins, 2 columns of six pins.
Left side
VCC P1
GND P2
FT P3
P-L P4
P-E P5
REC P6

Right Side
P7 F-T
P8 F-T
P9
P10
P11 P-E
P12 P-E

On the right side there are 2 jumpers, one P8-P9, one P10-P11. There are white boxes next to P7-P8 F-T, and P11-P12 P-E. There were no instructions with the module so some experimenting is needed by jumpering pins to see what happens. There might be a UTube vid for the module as there are for many of the chinese modules. If I was doing this I would use a piece of Female Terminal Dupont wire on the pins, Typical Dupont Wire on Amazon, cheaper elsewhere. https://www.amazon.com/SIM-NAT-Brea...=dupont+wire&qid=1566435719&s=gateway&sr=8-15 You can also buy terminal kits to make your own with 22AWG wire.https://www.amazon.com/QLOUNI-Housi...=dupont+wire&qid=1566436067&s=gateway&sr=8-17 Could maybe also be used on microswitch and battery holder pins? Good Luck!
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
So the switch should be in parallel to the battery? and both connect to the GND?
Then there is some unknown connection from GND to something else, possibly PlayE but that will take some tinkering?
The wire looks handy so might get a pack of those either way. Thank you for all the help - I will confess I am a bit confused, but I think maybe that'll get better with having it in front of me

What is DPDT? and how would I use this?
 

SamR

Joined Mar 19, 2019
5,031
What is DPDT?
A Double Pole Double Throw (DPDT) switch is a switch that has 2 inputs and 4 outputs; each input has 2 corresponding outputs that it can connect to. Each of the terminals of a double pole double switch can either be in 1 of 2 positions.

No the switch should be powered by the circuit board the same as the buttons on the board. Only take a short while to suss it out. I'd do it but desk covered up ATM with something I'm working on now.
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
Okay, not sure how I would use the DPDT switch here, as I've only one thing changing (Door open / closed)

Okay, so more like the series circuit I described before?
Yeh, that's what I'm hoping, but it'll take a couple of days for stuff to arrive from amazon and to get round to doing it.

No problem, no rush, and you've been so much help already, wouldn't want to put you out of your way.
 

SamR

Joined Mar 19, 2019
5,031
I think I would start with P-5 P-E to GND or VCC. Then maybe FT? I have no idea what FT is? Then there are the two pins marked P-T and FT on the right pins with the jumpers off to the side unmarked pins. What happens when both P-E pins or FT pins get jumpered?
 

iimagine

Joined Dec 20, 2010
511
I think I would start with P-5 P-E to GND or VCC. Then maybe FT? I have no idea what FT is? Then there are the two pins marked P-T and FT on the right pins with the jumpers off to the side unmarked pins. What happens when both P-E pins or FT pins get jumpered?
I posted a schematic, post #13, you dont have to guess
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
Okay so the bit where the microswitch actually connects to the board is a bit foggy until i figure out what everything does, but other than that the circuit described above was fine?

I wonder if anyone else who has had some time playing with the board knows which pins are best to short?
 

Thread Starter

Nicholas Mason

Joined Aug 18, 2019
25
It looks like PlayE is the option I want.
Okay, so:

Coin Battery Holder (with Battery) - presumably the +ve line > Magnetic Reed Switch > VCC > Common on Microswitch > NC on Microswitch > PlayE pin > Current travelling through the ISD1820 board > GND > coin battery holder - -ve line?
I did, I was more asking as confirmation, as I didn't have a whole lot of trust in my understanding of everything put together being bulletproof.
 

SamR

Joined Mar 19, 2019
5,031
Here is the PDF for the current ISD1820PY module. When pin P4 P-L or P5 P-E go HI it starts the playback. So VCC and P5 for microswitch contacts and for continuous playback looping jumper the 2 P-E pins P11 & P12. The 1820 is a smaller version of the 1800 chip which has 28 pins instead of the 14 pins for the 1820PY. Interestingly the FT pins are for Feed-Through, Mic to SPKR pins so it could be used as a switch contact enabled "Bug" to a recorder or XMTR. Mystery of the pins solved.

https://html.alldatasheet.com/html-pdf/1132094/ETC2/ISD1820/465/4/ISD1820.html
 
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