Beep-BRRR using smart home to extend its functionality

Started 14Oct2024. Updated 16Nov2024 (Movie. New unit added, with a knocking solenoid. DAY/NIGHT push button added). This page is in group My Beep-BRRR pages. It also is a follow-up from My missing smart home connection. Observe my Standard disclaimer.

Intro 1

(English) I have developed a device that I call Beep-BRRR because it listens for «Beep» and delivers a «BRRR» of some kind, like vibration under the pillow via a purchased alarm clock or flashing lights. Beep-BRRR contains sounds that have been recorded in the device, a maximum of two seconds each, such as a doorbell or fire alarm or mobile phone tone. In order for the warning from Beep-BRRR to be seen in several places, it is a good idea to have devices that flash, which can be placed where they are needed. This document describes a disconnection unit and a visual warning unit. Also a unit with remote alarm output only, and one with a knocking/hammering sound. There also is a movie. I have none of these to sell. I’m posting this because I think it might give some ideas. Especially the remote control of alarms. I use units from the Swedish company Plejd for this. You also have to download their app. Even if they do not notify if a device is not within range (see My missing smart home connection), they do work well when they are within range of each other.

I use some wirelessly controlled mains switches (Plejd SPR-01) to power some small boxes with boards which I have developed. A wireless battery-operated push-button unit (Plejd WPH-01) I «hijack» to become «pushed» by the alarm from a unit that I have developed (Beep-BRRR) when it has detected one of a list of locally recorded sounds. Now the hearing deficient is alarmed at several places.

Intro 2

In other words, for those that don’t hear well the idea is to have a unit listen for them. That’s all.

The problems that I show several solutions of in this note are

  1. The location of the listening unit(s).
    Where the (single?) critical sound audio listening unit Beep-BRRR should be positioned in a flat or house (scenario D has moved Beep-BRRR out of the bedroom to the entrance hall)
  2. The location of the blinking alarm units.
    How to distribute the alarm to places where proper attention for them is needed (scenarios C and D has remote alarm units)

Units

This system uses the following parts:

  1. My Beep-BRRR box that listens for in-product recorded sounds. One or twice one second for each sound.
    • See My Beep-BRRR pages. I have developed this 100% myself. It contains a 16 «logical core» processor board from XMOS, as well as at least 12000 lines of personally developed hard real-time software (much digital signal processing, DSP), written in xC for multi-core. (Since this is not a product there are of course alternatives (see some at 219:[Alternatives]). However, If you are in a company that would like to make this a proper product then just mail me.)
    • Beep-BRRR outputs a single 5V alarm pulse with Ri about 6 kΩ for of about 1/2 sec. over a 3.5 mm connector audio cable.
  2. An alarm clock BE1370 from Bellman & Symphon. It also contains a vibration actuator to be positioned in the bed, under the pillow etc. It is externally triggered by the alarm pulse. See 219:[Trigger other to do «BRRR»ing]
  3. Units that I built
    1. My pass/stop alarm unit. This is controlled by a 5V USB power in a Plejd SPR-01 on/off socket. When it’s powered a relay passes the alarm signal through. Also a switch to do the same. See architecture B and Fig.2
    2. Remote signalling. These are based on 555 timers, or rather a double 556. See architecture C and D
      1. My remote blinker/output alarm units. When 5V is applied it will first lit a white LED and beep and feed an alarm pulse out of the unit, for the alarm clock. The blinker unit will start to blink red and blue as long as the unit is powered
      2. My remote output alarm unit is a simpler unit that will only make the single alarm output pulse
      3. My remote knocking/blinking unit has no alarm output but the single start-up beep is replaced by a several loud knocks by a ham-
        mer onto the wooden bottom. The bulb always blinks
    3. The my modified Plejd WPH-01:
  4. Several units from Plejd [1]. An overall discussion in My missing smart home connection. Even if the error handling is (was?) not optimal, with the availability and ease of use, I have still decided to use them. Also because the flat where this is tested already had Plejd installed at several places
    1. My modified WPH-01 battery powered remote switch. In architecture C we see how I have fiddled inside one and had my own hardware, through a relay, «push a button» there. This hw is triggered by the alarm pulse. The alarm pulse is fed unchanged through the box
    2. There is one additional «flat» wall mounted WPH-01 shown in the figures. This is used in the flat for the «home/away» function which may be used to stop/pass the alarm pulse to the alarm clock through a scenario on the Plejd app and my pass/stop alarm unit
    3. Several SPR-01 on/off mains sockets. These units may be configured to, after power-up to do an «off» or to restore the previous value. (However there is no option for «on», see Wishes from Plejd, point 2, below). I did not read this from the manual, but form a support mail answer from Plejd. But if I had searched in the app I should have seen this without asking😀. All of these have a 5V USB adaptor plugged in which when on will power my units which will do their action
    4. The Plejd app on a mobile. This has an input → output action, optionally through a scenario.
      I have found no way to conditionally test states of Plejd units or state in a scenario. (Add a comment or mail me if I am wrong on this.) I assume that this may be a too complex task even for a smart user. Or even for the distributed architecture of the Plejd units. Like the WPH-01 has a battery life of ten years (two CR2032). This prompts me to believe that it does not listen to messages (since it also does not take part in the mesh architecture). To save power I imagine it only sends out a message when a button is activated. Of course, the Plejd GWY-01 gateway could have kept a state of that button, but even this would have its problems with getting synchronization correct without user intervention

Architecture A

Fig.3- Basic sound listening system with alarm clock and vibration actuator (with external power and battery)

This is the simplest solution. Beep-BRRR would show the alarm or alarms in the display and output a single pulse to the alarm clock on the first alarm. Beep-BRRR will repeat an internal beep every 30th second until the situation is reset by the user.

This alarm clock is externally powered and has an internal battery that’s charged by it.

Architecture B

Plejd: connect DAY/NIGHT to on/off and pass/stop unit

The configuration is done in the Plejd app. This communicates with the units by telling them to permanently store which unit to send their action messages to. After this the whole system will work without the Plejd app. However, the system may also be controlled and «debugged» from within the app.

  • This SPR-01 is controlled by two scenarios: DAY/NIGHT and HOME/AWAY
  • (1) NIGHT and (2) DAY would (1) power and (2) unpower the SPR-01 unit
  • (1) HOME and (2) AWAY should basically (1) do nothing and (2) unpower the SPR-01 unit (into DAY)
  • They take their inputs from their respective wall-mounted WPH-01 push buttons
  • The SPR-01 should have its output to be configured to «last state» at power-up. (See Wishes from Plejd, point 2, below)

Fig.4 – Sound listening system with remote pass/stop of pulse to the alarm clock

This opens for the alarm pulse to be shut off or connected through in a pass/stop unit that I built. With 5V appearing an internal relay closes and passes the pulse. With no 5V in the pulse is stopped. In that case a switch may short the relay contact and pass the pulse anyhow.

The below text first appeared in My missing smart home connection. It precedes the above text in this note, thus being a rather interesting precondition. I have only embellished the text some:

My «Beep-BRRR» unit needed a way to easily disconnect the bedside table alarm clock. This clock has sound and light plus a separate bed shaker, which are best kept silent every now and then. Especially when away. The spec was to disconnect this by breaking a wire in an audio cable. Disconnect with a «Home/Away» switch on the wall (not our wall, the user’s wall), a wireless push button (Plejd WPH-01) [1]. Or, by the Plejd app. (Or perhaps even by Apple Home (HomeKit) or Google Home or Amazon Alexa.) With or without a gateway (like Plejd GWY-01).

Fig1 – My missing link box with two Plejd units

What I could find from the Plejd assortment was a smart relay on/off plug (Plejd SPR-01). However I was not able to spot any galvanically isolated («floating») relay output, any 5V logical output unit or a 4-20 mA current loop output. Not anything that I could use. Was I blind, could this be true? Nothing of the sort that I could easily use to break a wire in the 3-5 mm audio cable. Or deliver a logical input to the Beep-BRRR for that sake, on a later occasion. Maybe the closest I could find was the 24V DC (Constant voltage, PWM-modulated, I assume) LED driver (LST-01), but even it is supposed to be connected to an IP66 protected LED list. I assume that since description of whether any of the Plejd products are galvanically isolated seems to be missing, they are not. But I don’t know.

Fig 2 – My disconnect audio cable control box (press for PDF)

My solution was to buy this SPR-01 with an internal relay delivering obviously not isolated voltage from the mains (230V AC mains, of course). I then plugged an obsoleted (but oh so small and nice and fitting the purpose) Apple 5V, 5W charger into it, and have the 5V from it control a 5V relay. And then design and build the (rather nice, to be a little modest) aluminium box, containing that relay. See the circuit diagram for some more text.

Observe Mains fail to safe (below).

Any better idea, Plejd? Even if your logo and name make sense upside down (nice!), does my rather upside down solution make sense? A floating from mains double throw relay would have been nice. But then comes the point of type of enclosure and DIY or electrician for installation etc. I can see reasons why Plejd don’t seem to approach the DIY marked. But from all the nice «makers fair» type of stuff out there, why not consider this market? (MikroE, Adafruit, Sparkfun, Hackster and Pimoroni, to name a few.)

Or would there be any other smart home appliance that could have solved my problem, outside of the Plejd infrastructure? (Comments are open).

Architecture C

First do the configuration in the Plejd app as Plejd: connect DAY/NIGHT to on/off and pass/stop unit (above).

Plejd: connect ALARM to blinker/output units

  • These SPR-01are controlled by a scenario: ALARM
  • ALARM takes its input from the modified WPH-01’s button by the green LED (set alarm) and the lower part (reset alarm)
  • (1) Set alarm and (2) reset alarm would (1) power and (2) unpower the SPR-01 units
    • This unit’s second push button could be configured to also be an input to the DAY/NIGHT scenario
  • The SPR-01s should have their outputs to be configured to «last state» at power-up. (See Wishes from Plejd, point 2, below)

Fig.5 – Sound listening system which itself «pushes a button» for remote alarm to blinkers. Also remote pass/stop of pulse to the alarm clock

This opens for the alarm pulse from Beep-BRRR to «press a button» on my modified Plejd WPH-01 wireless push button. This will send a message to the on/off units to become powered. This will cause my remote blinker/output units to start blinking red and blue.

Pressing the other side of the switch by hand will unpower the blinker units.

Fig.7 – Unit that «pushes a button» on the Plejd WPH-01 on the alarm pulse

The little board contains a MOSFET transistor that powers the relay when the alarm input sees the alarm voltage. The relay is not polarised, meaning that when the alarm pulse goes down (after about half a second), the relay opens again. The relay closed contacts I have soldered onto one out of four switches on the WPH-01 board. This switch I have decorated with a continuous weak LED, which lights more up during the pulse. See picture above.

The label I made for the above box goes like this, Norwegian and English:

Når alarm fra Beep-BRRR sendes en puls til denne modifiserte Plejd WPH-01 trykkbryteren. Pulsen «trykker» på knappen ved lysdioden. Da vil det varsles i blinker og alarmenhetene via Plejd SPR-01 av/på. En av dem er også tilkoblet alarmklokka. Avstill det hele her.
Skjema 42, blogg 261. Øyvind Teig 10.24
When alarm from Beep-BRRR, a pulse is sent to this modified Plejd WPH-01 pressure switch. The pulse «presses» the button by the LED. Then it will notify the flashing lights and the alarm units via Plejd SPR-01 on/off. One of them is also connected to the alarm clock. Stop it all here.
Form 42, blog 261. Øyvind Teig 10.24

Fig.8 – Unit that outputs a pulse and starts to blink when powered. The LEDs are inside a lamp bulb

The unit above is 73 * 73 * 49 mm. The dome is from a defect E27 LED bulb. It’s plastic and has a diameter of 60 mm.

The label I made for the box goes like this, Norwegian and English:

Når alarm fra Beep-BRRR «trykker» den på en modifisert Plejd WPH-01 trykkbryter. Da leverer en Plejd SPR-01 av/på enhet 5V hit via USB strøm-forsyning. Med en gang leveres en enkeltpuls ut på 3.5 mm lydutgang til eventuell alarmklokke. Blinker så lenge USB har 5V. Avstill på modifisert WPH-01 trykkbryter.
Skjema 43 og 44, blogg 261. Øyvind Teig 10.24
When there is an alarm from Beep-BRRR it «presses» on a modified Plejd WPH-01 pressure switch. Then a Plejd SPR-01 on/off device supplies 5V here via USB power supply. A single pulse is immediately delivered on the 3.5 mm audio output to any alarm clock. Flashes as long as the USB has 5V. Reset on the WPH-01 pressure switch.
Forms 43 and 44, blog 261. Øyvind Teig 10.24

You can download the circuit diagram of the modified WPH-01 switch, here.

Architecture D

Now do the configuration in the Plejd app as (above)

  1. Plejd: connect DAY/NIGHT to on/off and pass/stop unit and
  2. Plejd: connect ALARM to blinker/output units

In this architecture the Beep-BRRR has been moved from the bedroom to the entrance. Even if it does detect the door bell and the private fire detector and also the house of flat’s fire alarm with the bedroom door closed, it will get a better signal/noise ratio there. That’s the upside.

The downside is more ambient noise from the flat and probably more false alarms. But I am working on another algorithm to try to help on this.

However, the real downside is that it’s not possible to make this architecture fail safe to a mains fallout. See Mains fail to safe (below). One solution could be to keep the Beep-BRRR in the bedroom and install a second Beep-BRRR in the entrance. that would be architecture E

Fig.6 – Sound listening dislocated from the alarm clock. It only «pushes a button» for remote alarm to blinkers. Also remote pass/stop of pulse to the alarm clock

The new unit here is a simplified version of the remote blinker/output alarm unit. It has no bulb on top because it’s not needed where it’s placed, by the alarm clock. Instead it has a simple red LED that will light bright for the duration of the generated output alarm pulse, then blink weak from then on. As for the other unit, the continuous visible indication is a «nag blinking» so that the user will have to (or want to) acknowledge or reset the system by pressing the other side of the button on the modified WPH-01.

Fig.8 – Modified unit from fig.7 without bulb and with one LED only

The unit is 73 * 73 * 22 mm.

You can download the circuit diagrams etc. here.

Fig.9. The alarm output and short white blink is replaced by a solenoid that hammers two times per second for some 3 seconds

However, the excellent test user of this system said she didn’t hear the initial beep of the standard alarm units. Especially not when watching TV or doing something. The blinking did not get the attention it should have had.

You can download the circuit diagram etc. here. You will see that the use of the double 555 timer (NE556N) is used differently, also changing the behaviour of the unit:

  1. There is no single pulse alarm output since..
  2. .this timer is used to, some period after power-up, enable the pulses to the solenoid with «knocker» via TR2
  3. This solenoid is so power-hungry (about 1A at 5V) that I wanted to feed it only as much as was needed. So I gave it a 20ms pulse, made by an
    edge detect C6*R5 network and the TR3 MOSFET. Two 1000uF capacitors C8-9 now almost feed the solenoid for that period. This makes it possible to operate this from a 1A power (even a power supply with 100 mA limit seems to do the job)
  4. The timer has such bad high and low voltage levels using Vcc 5V and (1) the five red LEDs to and (2) the single blue LED to GND, that on this load it was not able to trigger the edge detect network. I had to add a level shifter and rise time shaper TR1. This was in order to not have to make a push/pull with two extra MOSFETs. Therefore the red LEDS pulse «long» instead of «short» and the single blue LED pulses «short» instead of «long», since all LEDs are pulled down from 5V now. I decided to use the high power 2905 HEXFET for all transistors, even if a 2N7000 would have sufficed here
  5. The blue LED now points down, on the wood that the solenoid knocks onto. The knocking comes out so load that the starting 20 seconds eventually was tuned into 3 seconds
  6. R13 current limits the gate of TR3, instead of using clamping diodes to remove excessive positive and negative signal. Max should be +5V on the positive slope and -5V on the negative slope. This is how derivation or slope detect works. The max. levels on the gate actually is ±16V at ±100nA, so R13 is not strictly necessary. However, R13 also is nice to limit the rise time of output current. The gate to source capacitor is about 1700 pF. So now we’d have from Q = C*U = I*t that t = (C*U)/I = 1700pF * 5V / 0.5mA = 17µs. So the power caps and the power get a better time since the coil will be nicer on them
  7. Power-up goes like this. The first LED blink is done. When the first blink goes dark the solenoid is pulsed. This means that the charging capacitors have the time to charge
  8. If a power-up is repeated too fast the knocking is not done at all, since 2OUT of the monostable just stays low because its trigger circuitry R3*C4 has not fully discharged
  9. The last knock in my case is weak. This is coincidental. There is no connection between the two parts of the 556 timer chip

This unit is 74 * 74 * 50 mm, plus the dome.

The label I made for this new box goes like this, Norwegian and English:

Når alarm fra Beep-BRRR «trykker» den på en modifisert Plejd WPH-01 trykkbryter. Da leverer en Plejd SPR-01 av/på enhet 5V hit via USB strømforsyning. Først høres noen dunk fra den innebygde solenoiden. Kula blinker så lenge USB har 5V. Ingen alarmutgang. Avstill på modifisert WPH-01 trykkbryter.
Skjema 45 blogg 261. Øyvind Teig 10.24
When there is an alarm from Beep-BRRR it «presses» on a modified Plejd WPH-01 pressure switch. Then a Plejd SPR-01 on/off device supplies 5V here via USB power supply. A solenoid immediately knocks several times. The bulb flashes as long as the USB has 5V. No alarm output. Reset on the WPH-01 pressure switch.
Circuit diagrams 45, blog 261. Øyvind Teig 11.24

The instrument. To some extent this little box was now going to take the function as a musical instrument. The sound should pass through hearing aids and more or less observant functional ears, on a brain concentrating on something else. I have discussed some of this at 219:[Making it «BRRR»]. I thought that the 5V solenoid I already had could hammer or knock onto something in the bottom. I tested several material like plastic, bakelite, aluminium and veneer. But it was some leftovers of 2 mm glued lists that won (from a jewelry box). I then glued this across over the box, leaving an opening to perhaps let the knock out. I don’t really know if this is a good idea, I just think it so, since without this the box might have absorbed more of the hit and the sound would have become more like dull, if that’s the right word. I haven’t measured the sound level, but it is rather load, but probably not painful for non-earache non-stressed tympanic membranes.

Knocker/alarm unit movie

See 219_movies[2024 11 16 – Beep-BRRR using smart home to extend its functionality]. This shows the test setup I have.

Architecture E

One Beep-BRRR in the bedroom and a second Beep-BRRR in the entrance. The one in the bedroom would have a UPS for it. The one in the entrance hall would not have any UPS. Whether one or both should have a modified WPH-01 I haven’t studied. Or if this is a viable solution at all.

One could of course find a small 230V AC UPS for the SPR-01 at the bedroom and have a simple 5V UPS for the Beep-BRRR in the entrance.

Maybe more later.

Issues

Mains fail to safe

UPS

I have not solved the Uninterruptible power supply (UPS) case for the Beep-BRRR. See 219:[Uninterruptible Power Supply (UPS)]. So for now, in case of a power failure, of all the units and architectures I mention in this blog note, none survive.

As mentioned the alarm clock has an internal battery.

Pass/stop must pass on no power

The unit as described in the circuit diagram in Fig.2 is not fail to safe. I need to invert the contacts on the relay to normally closed so that the alarm passes through when there is no mains power. See new diagram in here. This is not valid for architecture A and B. It is valid for C if I had a UPS there. However for D it would not be valid either, as the wireless SPR-01 will need mains being present and there is no way to keep them going without mains. The WPH-01 indeed has a battery built in as it is completely disconnected from mains.

Use of NE556N

In the future don’t let the timer chip NE556N when powered from 5V drive anything. Not even LEDs. They would light more if some buffer were added. See the knocker/alarm unit’s TR1 where I did get it as I want to.

Wishes for Plejd

I would like to see this from Plejd:

  1. The whole field of error detection and reporting, as indicated in My missing smart home connection to be redesigned
  2. Waived point: For SPR-01, after power-up I would want to be able to set to «on», not only «last state» or «off». This would only be needed for the non mains fail to safe version since there my usages may have states that may potentially change during a power outlet. With a UPS on Beep-BRRR the present state as «off» after power-up is correct

Fjernstyring av varlingsenheter

(Norwegian) Jeg har utviklet en enhet som jeg kaller Beep-BRRR fordi den lytter etter «Beep» og leverer «BRRR» av en eller annen sort, som vibrering under puta via en innkjøpt alarmklokke eller blinking av lys. Beep-BRRR har lyder som er tatt opp i den, maks to sekunder hver, som dørklokke eller brannvarsling eller mobiltone. For at varselet fra Beep-BRRR skal kunne ses flere steder er det jo lurt å ha enheter som blinker, som kan plasseres der hvor de trengs. Dette dokumentet beskriver en utkloblingsenhet og en visuell varslingsenhet. Også en fjernstyrt sak som bare har en alarmutgang. Jeg har ingen slike å selge. Jeg publiserer dette fordi jeg tenker at det kanskje kan gi noen ideer. Spesielt det med å fjernstyre alarmer. Jeg bruker eneher fra det svenske selskapet Plejd til dette. Du må også laste ned appen deres. Sjøl om de ikke varsler dersom en enhet ikke er innefor rekkevidde (se My missing smart home connection) så funker de bra når de er innafor rekkevidde. Jeg har også lagd en enhet som varsler med en aktivator som dunker i bunnen av boksen noen ganger før den går over til å blinke fast. Se film her.

References

Wiki-refsUninterruptible power supply (UPS)

[1] Plejd, see https://www.plejd.com

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