Still having power issues

Steve2381

Steve2381

Senior Member
Well basically I think I have fixed all the issues... except the HC-06 problem.
It all works with the HC-06 out of circuit. With the HC-06 in circuit, it constantly triggers itself until its paired with my phone. Then it works fine again (doesn't re-trigger itself).

So, something in the HC-06 while in un-paired mode messes up the power bus.
I have tried the HC-06 with the data lines disconnected, and just the power supply - still does it. So it must be something to do with noise.

No amount of capacitors across the supply clears it. I tried right up to a 10,000uf cap.

There is a in4001 inline with the 5v supply to the HC-06. That doesn't help. Can't put one in the 0v, as the voltage drops too low and it doesn't work.
Same goes if I move the HC-06 off circuit. The supply must be right on the borderline, as the lead resistance was enough to drop the voltage too low for it to work.

So, my only other option is to somehow make that default circuit for the Biss0001 less sensitive. However, I do not really understand all that R/C network and the op-amps inside the IC, so I have no idea what to change to achieve a less responsive sensor.


View attachment 19732
 
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alhoop

Member
steve.jpgSteve:
Is one end of R11 floating? looks like it on the PCB.
PS - guess not - it looks correct on the finished board.
Al
 
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inglewoodpete

Senior Member
Steve2381 said:
Can't...... walk....... away

Must...... find....... problem :confused:

Nearly eliminated the issues. So very close. HC-06 (The replacement). When waiting in pairing mode, still upsets the whole circuit. Once paired, it doesn't seem to cause issues. It must put noise on the circuit while it is transmitting its pair signal
Click to expand...
Many wireless devices will try to 'pair' at all costs, a function of their firmware. Mobile/cell phones searching for a network connection are a common example. They send out a series of echo tests, usually while ramping up the transmitter power. Once an response is recognised, levels are reset depending on the received or negotiated signal level. It is possible that cheaper ones just blast away until a response is received before resetting the transmitter power to a mutual level.
 
PhilHornby

PhilHornby

Senior Member
I think I reproduced this fault...

Steve2381 said:
So, something in the HC-06 while in un-paired mode messes up the power bus.

So, my only other option is to somehow make that default circuit for the Biss0001 less sensitive.
Click to expand...
I dug out my BISS00001 Chinese night-light module and an HC-05. With the BISS00001 running on isolated 4.5V battery power and its PIR sensor covered, I got false-triggering when I dangled it in the middle of the breadboard containing the HC-05!

It wasn't exactly reproducible at will, but the effect was definitely there. Moving the module away from the breadboard stopped the false triggering completely. There was no electrical connection between the two circuits.

So ... I conclude that the answer is not smoothing (or filtering), but shielding. (And you owe that pretty little Vigortronix PSU an apology :))

Looking at the photo of your board, perhaps you could add something like a piece of copper-clad PCB board at 90° to the HC-06 ... and connect it to GND. Something underneath the PCB to shield the relay might be required as well. This is definitely not my area of expertise, so hopefully you'll get some better suggestions.

(There are worse things for a BISS00001 to have to contend with than an HC-06 though. When I stuck my test module in the middle of my 3xESP8266 breadboard, it triggered immediately and stayed triggered until I removed it!)

One thing I did notice about your circuit, was the arrangement of the caps. around the HC-06. As it stands, with them connected to the collector of the transistor, there is a little pulse at the output of the BISS00001 every time the transistor conducts. It only lasts about 380uS and is tiny (120mV). I doubt it affects anything, but connecting the caps. directly to GND gets rid of it.

As unrelated observation, I was impressed by how sensitive these PIR sensors are - to block it, I used a piece of paper folded multiple times, held in place by 2 layers of insulating tape. If it put my finger directly on top of the sensor, it still detects it!
 
Steve2381

Steve2381

Senior Member
Thanks all.
No - R11 isn't floating. I think that may have been a previous pcb layout image, but its certainly connected.

Thanks Phil. I will remove the IN4001 that supplies the HC-06, and move it further away. Kind of messes up my enclosure layout, but hey ho.
They are super sensitive, and that appears to be something that has lead to many problems!

I will look into the capacitor issue as well.
 
Steve2381

Steve2381

Senior Member
Well another few hours on the dreaded project.

Its not shielding Phil (well, at least I don't think so). I made up a 2' lead and ran the HC-06 away into a metal box to keep it away from the circuit. Still does it.

While waiting to pair, it constantly triggers the sensor. Unplug the HC-06 on its long lead, then the problem goes away. Maybe too much current while waiting to pair? The PDF says 40mA in pairing mode, dropping to 8mA once paired. Its a 1000mA PSU, so that should not be the issue.

I cannot think of anything else I can do to address the problem this bluetooth module is creating. Trouble is, without the bluetooth, the project is dead.

So, options....

1/ Bigger Vigortronix PSU (higher amperage). However this renders the power PCB useless, as it won't fit and I am also not convinced it will get rid of the problem (oh, and its more money).
2/ Second Vigortronix PSU. One for the circuit and one for the HC-06. Higher chance of this working, but again.... the pcb will be toast and also the whole thing is getting a little over developed (it was supposed to be small format). Oh, and more cash.
3/ Continue to prod it with a stick in the hope that I can find a way of removing this problem.
4/ Abort mission and say that's enough.
5/ Hit it with a hammer

Option 5 is looking favourite
 
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eggdweather

Senior Member
Try a kitchen raid and wrap your main board with aluminium foil, put your board in a plastic bag then wrap it up like a turkey with foil to act as a screen whilst the HC06 is pairing, where I expect it will be emitting higher than normal RF until the link is established, then it reduces power, it could be the problem is the result of induced RF currents, if that works, then house your control circuit in a screen box. If it does not work then who knows...
 
Steve2381

Steve2381

Senior Member
Well if it is an RF issue, then the project is screwed anyway. The HC-06 cannot be mounted remotely to the PCB by much, as the whole PCB is enclosed in a 3d printed enclosure that is wall mounted.
It wasn't something I ever thought would be an issue.
I will try moving it even further away just to see, but I think we have reached a road block here

These HC bluetooth modules are a pain in the butt
 
PhilHornby

PhilHornby

Senior Member
Steve2381 said:
Well if it is an RF issue, then the project is screwed anyway. The HC-06 cannot be mounted remotely to the PCB by much, as the whole PCB is enclosed in a 3d printed enclosure that is wall mounted...
...These HC bluetooth modules are a pain in the butt
Click to expand...
IMHO you need to look at the problem the other way round - the BISS00001 circuitry is very sensitive to external interference (as I can demonstrate at will) - in an ideal world it should probably all live inside a screening can.

What about my suggestion of the copper-clad board(s)?

EDIT

Building on eggdweather's metallised bag idea ... could you make some sort of customised 'screening can'? for the BISS00001 section of the board. 3D printed? ... or even cardboard? ... then glue some aluminium foil to it...
 
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premelec

premelec

Senior Member
I use thin copper foil which can be easily bent and soldered to - however also 'tin' can [not aluminum] will give electrostatic shielding and some magnetic shielding as well - can be cut with heavy scissors [not your spouse's favorite cloth scissors!] and soldered to .... think cans... :)
 
S

SAborn

Senior Member
A theory I would try is looking at the input circuit from the PIR sensor.
Consider changing R5. and even C2 to different values.
Put in a 10K for R5 and see what changes, perhaps increase C2 after as I would think either will will adjust the response sensitivity, appears to be over sensitive in its input function.
 
Steve2381

Steve2381

Senior Member
Not sure what that link is Alhoop - doesn't work. Another 5v supply is an option, but that does mess up the PSU board (not that its an issue really I suppose).

I will try the shielding tonight. I am going to run the HC-06 off a separate supply again, just to see if it really is the supply or shielding (or both!)

I have messed about with R5 and C2 values Saborn without much luck. I will try them again however.
 
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alhoop

Member
reg.jpg
Steve2381 said:
Not sure what that link is Alhoop - doesn't work. Another 5v supply is an option, but that does mess up the PSU board (not that its an issue really I suppose).
Click to expand...
That was a link to this item on EBAY. Don't know why it doesn't work for you - does for me.
PS please try that link again.
Al
 
Steve2381

Steve2381

Senior Member
I have just spent a few hours on this.

I made a shield for the Biss0001 and tried that. No difference. I ran the HC-06 off its own supply and dangled it over the top of the Biss0001 and it did not interfere or trigger it. I am pretty sure shielding is not the issue.

I tried various values in for resistor R5 and capacitor C2. No change.

The HC-06 is pulsing 0 to 30mA while it is waiting to pair. That is a decent pulse to the system I suppose. A 10,000uf cap across the Bluetooth module supply did not help with the pulsing.

I just noticed the relay is now not turning off after detecting movement, so something has gone screwy with me playing about with it. Might just need the software resetting.

But... tired of it now and I think I am going to put this one down to experience. I do not want to buy another PSU to run the HC-06, as I am far from convinced that will cure the issue and throwing more pennies at it is just a waste.
Its been interesting. No more HC-06 modules for me!
 
PhilHornby

PhilHornby

Senior Member
A final thought!...

Steve2381 said:
It's been interesting. No more HC-06 modules for me!
Click to expand...
It occurred to me, that if your problem is entirely HC-06 related, then why not leave it OFF, except for the presumably rare occasions you want to use it (at which point the BISS00001 proximity detection can be temporarily disabled).

Something as simple as adding a switch in series with the BC548 ?
 
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alhoop

Member
Whatcha going to beleive? this or ??????????????

From Electronic Design article "The Engineer’s Guide To High-Quality PCB Design"

'Components absorbing greater than 10 mW or conducting more than 10 mA should be considered powerful enough for additional thermal and electrical considerations.'

"post#1
If I remove the HC-06 from the circuit and run it on its own 5v supply, it works again.
poat#4
The minute I feed a separate 5v to the HC-06, the problem goes away.
post#6
Worked ok when the Picaxe didn't share a 5v supply with the HC-06
post#7
Running the HC-06 on its own 5v rail still gives me intermittent comms issues.
post#13
The HC-06 works.... just not when it shares a supply with the Picaxe.
post#16
Give it its own 5v supply and it works again.
post#96
I ran the HC-06 off its own supply and dangled it over the top of the Biss0001 and it did not interfere or trigger it."

Al
 
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