Posts made by bjacobse

Offtopic, but I like your bricks on your house

is the D2 pin also connected to the RF module?

I'm quite lazy, and use this approach and use a USB powerbank, and check if DHCP server is alive or dead (Dead= no 230V)

https://raspi-ups.appspot.com/en/index.jsp

@berkseo congratulations

@malachite666 said in Please help with rspro itx 3d printer:

RSPRO itx printer
It looks like it's a private label name, and the manufacturer is Kora3d, you need to talk to those people and if you can't get any further support, don't waste any more money on this and buy yourself an Iprusa and get support from all the people that owns such a device

https://www.kora3d.com/products/kora-pro-3d-printer-range/kora-pro-3d-pc-printer

@barrydou
https://electronics.stackexchange.com/questions/2262/decoupling-capacitors-what-size-and-how-many

@skywatch
I'm amazed that you made it work, which is good in your case
But in most cases it might not work, and your MCU will crash RAM/stack and you will have troubles to understand what goes wrong.
https://electronics.stackexchange.com/questions/146298/what-happens-when-microcontrollers-run-out-of-ram

So to be on se the safe side for most people, then buy 328 as it from Mouser only cost 1,92€ and the 168 costs1,40€ for the cheapest variant of each, so for a hobbyist this price is nothing compared to the troubles you might have. Naturally if you have production and manufactures thousands devices this price different is extra money in your pocket

I'm sure ATmega 168 have too little memory to be used for run the mysensors code... so don't buy a ATmega168

ATMega 168
Program Memory Size (KB) 16
SRAM (B) 1,024
Data EEPROM/HEF (bytes) 512

ATMega 328
Program Memory Size (KB) 32
SRAM (B) 2,048
Data EEPROM/HEF (bytes) 1024

@Jasonkeel
The green is the flex PCB,, as you can se how it' turn 90degree a few times

Inside Hearing aids, the PCB are "mainly" only flexible PCB as the PCB must bend and follow the mechanical shape, think this picture gives an idea
https://www.manualslib.com/manual/1902167/Oticon-Aurora-Minirite-312-T-Rc.html

How does your function work with 5 samples and throws away errors?
Why not take measures until you get 3 or 5 measures that are identical, and then use this as your measurement?

@markjgabb
If you want to run on batteries, which is a good option, then just make a reading every 10sec, and make the MCU sleep and save precious battery. It's not needed to measure each pulse every second

Pseudo code:
wakeup after 10sec
wait until you get a reading, unless you have waited 5 sec (timeout to save battery)
send pulse detection
sleep

@MatiasV No-no, you need much more stuff before it will be "average"

@alex28 As your critics reads for me as constructive feedback, then I will suggest for you to enable you to get a positive experience (I have been around Mysensors since May 2015) I use it with Domoticz as this is what I like
Anyway start with simple things, I have my Domoticz on a RPI attached to the serial gateway, it's simple and reliable and "easy" to debug

Make sure the gateway is working on your home automation, and then proceed to make 1 simple windows sensor
https://www.mysensors.org/build/binary

And then you can make additional sensors to your network. Please note that Domoticz is the controller, and hence it's Domoticz that will allow a sensor/node to be "added" to your network. The serial gateway is not having anything to do with "adding" nodes to your network, it's just a "dum" gateway moving data from the sensors to your homeautomations

Any other Homeautomation than Domoticz is equally good, if they have Mysensors support

To make your start easy:

• Don't use ENC28J60 to make a gateway
• Make a serial gateway
  https://www.mysensors.org/build/serial_gateway
• Don't spend too much time on NRF24L01+ as MANY of those are counterfeit China-shit, and you can debug for hours not understanding why your setup isn't working. Replace NRF24L01+ immediately if it ain't working
• Verify that your NRF24L01+ are in good working condition, before using them (if possible). Do you have a friend that have a some known good working NRF24L01+, then borrow a few pieces
• ALWAYS use a capacitor as close as possible to your NRF24L01+ radio modules voltage supply/GND
  https://www.mysensors.org/build/connect_radio#connecting-a-decoupling-capacitor

And then I'm quite sure the Mysensors-community would like if you can support to update the documentation to become better for the next new persons that would like to start using Mysensors, so the frustration that have been around your start can be reduced for the future

@echi Basically it's quite simple, it's the whole device that needs to comply to the rules, and not ONLY the radio-part of your design.
so it's not possible to "buy" a radio approved RF IC and then add this to your own design, and then think this is adequate

@echi Have you checked the price for getting the FCC and radio approvals? it's quite expensive. As it's mandatory to have an independent test company to do actual test on your devices as a part of the documentation. Furthermore you need also to get country approvals (Notified Body) for several countries where you want to sell you product, fortunately as I recall EU only requires approvals in 1 country to be valid in the rest of EU countries.

This link is from 2014, but gives you an idea what kind of approvals that you MUST get prior selling your stuff
https://www.quora.com/What-is-the-average-cost-to-get-FCC-and-CE-certification-for-a-very-simple-electronic-gadget?share=1

@skywatch said in Is it worth it adding a reset circuit to MySensors nodes?:

@bjacobse Good point, but what happens if it freezes during sleep?

It's NOT possible, it's in sleep, it's an integrated part of the IC design, and such a bug would have been found many years ago. The ATmeag328 will go into a well defined state, which is sleep, until it's getting woken up, by an interrupt or a timer.
Naturally the registers are required to be setup up properly

As I wrote, you SHALL disable WDT (watchdog) prior entering sleepmode, and after wakeup then you enable WDT again, else the WDT will reset the Atmega328 while you are in sleeep

ATMeag328 documentation:
http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf

Just wondering why not use Watchdog?, it's supposed to restart MCU when it freese.
The watchdog shall be disabled before entering sleep state and enabled when wake up.

I would recommend to set the watchdog to max time=8seconds. then you only need to clear the wdt every 7 sec
As I recall the default bootloader in Arduino, doesn't have the WDT enabled, so you shall flash Optiboot or similar bootloader

I searched for an example:
https://www.electronicwings.com/arduino/watchdog-in-arduino

do as Zboblamont suggest.
I have my distance sensor to measure in a loop until 3 last measurements are equal. Unfortunately it's a few years ago so I no longer have the code

@GarethBirkett
no worries man, you described somehow how it functioned I just newer heard of a oil vaporizing AGA cooker/stove

somehow your description is a bit misleading:
"The oil flow is controlled by an electric regulator and is either high fire, or low fire. The default is low fire, but when the thermostat detects that the temperature has dropped it sends a signal to the regulator to turn to high fire, when the temperature is reached it switches back to low fire and so on maintaining the temperature range."

you are linking to a thermostat, with a connector of 2 pins.

so the AGA must have a low fire at all times, and when the thermostat are activated (when temp is lower than set temp on the knob) it start high fire.

so basically you just need a relay that can withstand the current of the oilburner. check on the current thermostat it must state the current it can withstand, then a DS18b20 and an Ardino connected to your favorite HomeAutomation controller (domoticz, homeassistand, HomeSeer)

And then you can swith on/off from homeautomation from your phone

Just remember to create the code so you measure temperature and relay must switch OFF at a set temperature so you wont overheat the AGA and potentially burn your house down

I would though image price gets too high if those are sold as pre-assembled. (These devices are hand made, and not manufactured by a real manufacturing line that manufactures thousands per day) Are you able to solder? I think most of the guys developing HW here are willing to sell off their PCB, so you "only" have to solder connectors and a few lead through components to the PCB to assemble the PCB together.
If you are not able to handle soldering, then search for the nearest Fablab in your area, as there are skilled people that most likely are willing to teach you how to solder: https://www.fablabs.io/

This could be a good start:
https://forum.mysensors.org/topic/2740/easy-newbie-pcb-for-mysensors

More good stuff to be found via this link:
https://forum.mysensors.org/category/30/openhardware-io

@tbowmo
Looks really good, hope you will spend many good hours doing some fun stuff

Thank you for the nice compliments, but I'm not an expert, I just know something, and listen to our technicians at work. I work for a hearing aid company, in our PCB manufacturing plant

Yes hydrophobic coating, the machine is quite expensive, so a now retired technican made the machine himself, (He is also a quite bright guy), anyway a similar machine can be bought from Europlasma https://www.europlasma.net/products.html
as I understand the gas (teflon I think is used as gas) is sprayed inside a vacuum chamber, and then the hearing aids with electronics are rotating (Like a slow tumblking washingmachine),
and then after a while not sure but about 20-25min the process is finished.

@NeverDie
We don't use conformal coating. But we use hydrofob coating of the whole device, so w avoid water ingress through the plastic box

Those few IC that we dip in flux, is because they have solderballs on the IC from supplier, the remaining components will have solderpaste on each solderpad in PCB.
We don't "remove" flux, we just forward the PCB on conveyor belts into heating oven (REHM reflow solder oven, with Nitrogen gas, to get better solderability as there will be less oxygen interefering during soldering in oven)

https://en.wikipedia.org/wiki/Reflow_soldering

We always "bake" PCB to get humidity out, and then afterwards those are stored in special non-humid cabinets until we take them out for SMD manufacturing

typically baked for two hours at 105 – 120 °C
http://www.surfacemountprocess.com/uploads/5/4/1/9/54196839/ipc-1601a.pdf

Those days while I worked for Nokia (which is at least 10 years ago), and I were at our factory plant in Beijing, some of our local chinese Nokia guys, bought Arduino stuff from Taobao and at this time, Taobao was much cheaper and quality was perfect

regardless if those are counterfeit or they are production rejects, selling those as "good" and "original" is just not appropriate - this leads to that noone will buy from the "grey area"Chinese suppliers...

And not to prejudiced against China or Chinese people, there are good and untrustworthy people in all countries

You can't trust China these days... As many DIY people a few years ago purchased a lot of electronic stuff from China, the counterfeit industry scaled the growth too

If you can take the "original" and program and it's working flawless, and those cheap Chinese ain't working, then assume they are counterfeit...

https://forum.mysensors.org/topic/9388/atmega328p-au-counterfeit/18

As I recall the ENC28J60 is haveing the IP protocol on memory of the Arduino, most likely you will run out of memory and getting weirds errors/reboots
When using the Ethercard/W5100 shield, this one have the IP protocol embedded and then there is room for Mysensors code adn other stuff in the memory

The technique with a large GND-plane can be quite well used when dealing with RF circuitry
But I agree this isn't pretty looking electronics...

@Joe
Sorry no idea where to get an Utrusta power supply

I think this is the most difficult part in the whole tasks in our household...
The kids will soon learn to leave the dirty laundry somewhere else, so the baskets are empty and there are internet (tryk avler modtryk).
I somehow think old-fashioned dog/punishment training are working - what will happen if the don't get their clothes laundered and it's left dirty?!?

Now being serious, can you do something with a strain-gauge, so you can measure the weight of the basket, if it's placed inside the cabinet on a shelf? then you can to improve WAF add a "false" shelf, that the loadcell/ strain-gauge is lying below, so that it actually are hidden

Help to understand strain gauge and load cells:
https://www.homemade-circuits.com/weighing-scale-circuit-using-load-cell-and-arduino/

Will your share the schematic files? or a picture of it?

https://github.com/dkjonas/Wavin-AHC-9000-mqtt
iron and toner transfer, then etched and soldered and finally acrylic spray on cobber so it won't corrode

wifi uses a lot of handshaking for communication = drain batteries too fast
Mysensors and other "good" protocols have a little handshake and preserves battery energi
I am only using wifi devices that are mains/230V powered

Why not purchase a Raspberry Pie and a SD card + casing , then you have a server?

@noclue said in Sensor advice:

@hj_sk I want to control my idea. I have put my ideas out there before, only to be stolen.

either do as Tbowmo suggests, or if you are afraid that we will all steal your idea, I can recommend to contact a electronic development company, that will sign a non-disclosure contract, a company could be this one (I'm not affiliated with the specific company)
https://www.prevas.com/

Typically wifi consumes considerable energy for handshake so use wifi on battery isn't the greatest idea. but using it with mains power is quite good

If you want to use battery operated devices, you must use a better protocol than wifi

https://electronics.stackexchange.com/questions/462754/how-to-send-the-key-sequence-ctrl-q-to-a-serial-port
https://forums.ni.com/t5/LabVIEW/How-do-i-send-a-quot-Ctrl-C-quot-character-to-serial-port-RS232/td-p/24213?profile.language=en

https://duckduckgo.com/?q=termite+ctrl-q&t=canonical&ia=web

Where I work we do all inhouse and we won't work as a sub supplier. but I know we have in some cases used this company when we didn't had capacity in our own factory for small prototype series

https://www.hp-elektronikmontage.dk/

As you just started your company and to hold back the money, why not as a start get someone to solder the boards for you? yes it's more expensive per board, compared that do it yourself, but then you don't need to spend money on a reflow oven that maybe isn't worth the money

Then when you have a cash-flow in your company and earn money, then you can start to purchase equipment

Depending on what you need to solder, you might need to also use Nitrogen, to get better solder-ability.

Then again it's difficult to provide your an advise, as noone know what your requirements are?
I work for a hearing aid company, and it's a medical device (FDA are inspecting us), which require the oven to be validated- and this requires s a lot of documentation.
We use Rehm ovens with nitrogen, and most likely this isn't what you need

https://www.rehm-group.com/en.html

@toccaraknauss Welcome

Why not as proposed make a small hole in the wall and insert maybe Si7021 sensor into the hole in the wall:
https://www.mysensors.org/store/temperature

But something else, why is the father not finding the rootcause for the wall to become wet?

To prevent false alarms is quite difficult,

1. as you might think a high acceleration (during falling) and then no movement after he have fallen and lies on the floor.
2. but false alarm could be he just sad down very quickly in the sofa and then relaxes
   how to distinguish between scenario 1 and 2 ?!?

Maybe you also need to check his pulse?

I don't have a google box, but can that be set to listen always, and if a sound similar to his fall are recorded then you shall be alerted?

You need this type of sensor: https://en.wikipedia.org/wiki/Accelerometer

MPU-6050 3 Axis Accelerometer + 3 Axis Gyro
https://www.mysensors.org/store/motion

@bjacobse
answer to myself, it appears that the chep multimeter types with Current clamp, is only capable of measure AC current, I need also to measure DC current (Then I can measure if my my diesel glowplugs are working, without removing anything), so I bought this fairly cheap add on.
It provides 1mV/A
https://www.aliexpress.com/item/33028995595.html?spm=a2g0s.9042311.0.0.115a4c4dFflk4A

How to measure with current clamp your glowplugs: (Not my video, but it gave me some knowledge):
VW T4 Transporter -- Startprobleme: Vorglühanlage überprüfen – 11:40
— Sascha Supertramp

And now we have opened the discussion, does any of you know of a current clamp as add-on to use with a regular multimeter? or must I purchase a dedicated multimeter with current clamp?

@crumpy10
Try FIRST to level your bed - PLA can't stick to air if you have too much distance between nozzlehead and bed.

@alowhum
NO it can't be used as 3D printer, it's not accurate enough
QA from their homepage:
Would it be possible to place circuit components on circuit boards using this arm or does it not have enough precision?

Yes, the repeatability is 0.2mm, This is enough for PCB soldering.

My 3D printer, zonestar 802 have this accuracy:
XY-Axis Positioning Accuracy: 0.012mm

@crumpy10
Looks like your skirt are fine (The round first prints) but inside your print you get to little PLA through your nozzle
is temperature correct?
is is a good source from PLA? or is it that came along the 3D printer, then swap and use new PLA
If you have Bowden extruder, is it extruding correctly? maybe the gear slips
And then maybe is your bed 100% calibrated?

I don't think your nozzle is clogged as the skirt looks ok

@bjacobse
did you setup Node-RED?
Maybe this can help you: https://diyprojects.io/mqtt-mosquitto-communicating-connected-objects-iot/#.XTBAKiZJFCU

I don't use Webthings, but MQTT shall work similar, on my RPI I have Domoticz and Mosquitto broker running, check in a prompt:
Is the broker running? ps -ef |grep mosq
you can also check the logfile: sudo tail /var/log/mosquitto/mosquitto.log

Then if above is ok, then your test message shall appear in the logfile, then Mosquitto is working. Then next check Mosquitto WebThings connection. I would assume a logfile must be present in WebThings that shows if a sensor is providing something

@berkseo
Good looking device that you have created originally

@nca78
I think you must have misunderstood the concept. I did not use a ethernet splitter and extra cable mess...
I use my router as IP supplier, 1 ethernet cable to my RPI, so I have cable to my domoticz, the RPI gets IP via cable, and if the I'm not able to ping gateway (router) then there is no power as the gateway is down.
the ONLY extra thing I have purchased is a the powerbank

@mfalkvidd
The powerbank I am using is a Linocell 7800mA. YES I AM AWARE that it's stated on the powerbank that it's not allowed to both charge powerbank an use it as powerbank - But that is exactly what I do
Bought here:
https://www.kjell.com/se/produkter/hem-kontor-fritid/fritid/resetillbehor/powerbank/linocell-3x-dual-powerbank-7800-mah-bla-p96870

@nca78 said in Raspberry Pi3 alternative?:

Do you also use the ethernet switch as a power sensor ? I would just use an USB splitter before the powerbank, then use one wire and a voltage divider to connect it directly to a GPIO...

There are typically many paths to same solution
It was easiest for me to just copy exact same setup - why should I bother to purchase an USB splitter and spend time to setup a voltage divider and create a script that needed to measure voltage on a GPIO

@berkseo
Clever idea to use SN74LVC1G00 as while both inputs are same voltage it only consume ICC = 10uA (10 mircoA) in whole voltage range 1.65V -5,5V

@zboblamont
I use a RPI3 and use this UPS (powerbank + script), as it's cheap and useful
http://raspi-ups.appspot.com/en/index.jsp

@zboblamont
Maybe find an old laptop, and keep it always connected to main 230V, and then create a script that will shutdown laptop if power failure after maybe 5 min.
ususally an old laptop easily can run a headless linux (No GUI that consume the sparse memory)

Love to to watch all you creative designs

@tbowmo
Well I must admit, it's just put in place - which means I have not yet started to use it - It must be messy when in use

As I have updated my workshop, so I no longer sit at my family kitchen table, but instead have a man-cave, behind a sliding-door closet, next to the water-heater

looks nice
https://en.wikipedia.org/wiki/Inclinometer

your can use JEDEC solderprofile as guidance, as Pb-free (Leadfree) is standard nowadays and the max temperature is 260°C, which can be seen in below solder profile. and don't heat it too long...
https://www.cypress.com/file/41231/download

Have you disabled internal pull-up resisters? on the ATmega 328?
Maybe try:
What is the current consumption when no JSN-SR04-2.0 is attached?
If this is low, then try to measure current that the JSN-SR04-2.0 is using?

Well then another approach is not to use DS18B20
Have you checked TMP117 price seems to be 2USD in higher qty, and supply range: 1.8 V to 5.5 V

http://www.ti.com/product/TMP117

https://www.digikey.com/products/en/sensors-transducers/temperature-sensors-analog-and-digital-output/518?FV=ffe00206&quantity=0&ColumnSort=1000011&page=1&k=TMP117&pageSize=25

And someone have made a lib to Arduino: https://github.com/NilsMinor/TMP117-Arduino

@pihome yes nothing is free;-)

@crumpy10
I use Freecad as it works on Linux/Ububntu
Why not use the CAD program that already are using and are familiar with

It appears that you during runtime can change prescale, so you should be able to change clock frequency to 8MHz when reading DS18B20 and after reading change clock back to 1MHz

https://forum.arduino.cc/index.php?topic=223771.0

I use this setup:
https://www.domoticz.com/wiki/ESPEasy_Aircondition_Inverter_IR_control

check if your heatpumps protocol is supported:
https://github.com/ToniA/arduino-heatpumpir

@mbj
And please share you experience using 2 extruders when available, (as I agree it is a nice enhancement) after a novice have become experienced using one filament/extruder

@skywatch @mbj
I think you are experienced and - and would you really recommend for a fist time use/novice as the topic poster to suggest printing in more than 1 colour? as beginner you need advice to get started and get success, and build competence, then you can later on move to a higher level, modify your printer and print with several colours

@skywatch said in Best 3d printers:

@mbj Also know that colour 3d printer are now available and likely to become the norm sometime in the future. So something to bear in mind....

Doesn't matter, if you need it in the future, buy parts for it when you need it. I purchased to be "future" safe a version with dual hotends, so I during print can change and use another colour. I thought it could be nice if I print a box and embed name for input or output in another colour. I have not used it yet... as Dymo labels are easier

@pihome
You need something that have IR underheat, to heat up your PCB from underneath,
so your hotairgun easily melt solderpaste and don't blow your IC away

I have a zonestar P802QR2, it's ok, if you can assemble it yourself. I use Cura as STL converter. and I have a RPI with octoprint. http://octoprint.org/ Then I can send my Cura converted files directly to my 3D printer. I have also MQTT installed so my domoticz is aware of the percentage that have been printed, so a little script switchs on a light when 99% is printed + send me an email

My best advices:
0) Get a Iprusa or clone (Mine is clone) (don't flame war this topic, it's an advice to a novice to get started easily. It's quite seldom your first car is the most expensive Mercedes.. Get the point...)

1. When assy screws then use loctite to secure, else screws will unwind due to the stepper movements
2. heated bed, and add a 3mm glass on top, and spray a thin layer of hairspray on top of glass plate. then you PLA will stick nicely
3. Start to use PLA, and ONLY PLA until you are getting experienced
4. calibrate you heatbed often. This is typically your problem if print fucks up
5. still got printing problem, look here: https://www.simplify3d.com/support/print-quality-troubleshooting/
6. Don't let your PLA get exposed too long to air, as it is hygroscopic and moisture will damage your PLA, so sometimes get new and fresh PLA is also helping

Here is a 3d printing from my white PLA print motor mount for BOFU motor to use with IKEA Tupplur blinds, STL files can be found here: https://www.thingiverse.com/thing:2878875
3D printer, Zonestar P802QR2 – 19:21
— Brian Jac

@creaky said in Recommendations for soldering temperature:

Here is a super interesting article about the science of soldering and how soldering affects electronic components.
Fun fact; ICs aren't watertight!

Off cause IC are not watertight.
In real production, IC are either stored in Nitrogen boxes, and/or baked according they MSL level, otherwise when those are running through the reflow-oven they will due to moist, as the moist are becoming damp, yes pop like pop-corn that pops, hence pop-corn effect
https://en.wikipedia.org/wiki/Moisture_sensitivity_level

And the reel (that have the components) are ALWAYS vacuum sealed (with an ESD bag), and MSL level is written on the outside, like lot/batch number and partnumber

This below circuit is using a xtal and the 2 caps, it seems that you don't have those
https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard

also it seems that you need to have a wire to AtMega 328 RESET pin connected from your programmer
See this link:
http://www.electronics-lab.com/burning-the-bootloader-on-atmega328-using-usbasp-programmer/

@zboblamont said in Nano minimum voltage:

@arden With so many more efficient boosters available than stock voltage regulators I have to question the wisdom of detuning any device to accommodate the power supply for all but the most extreme requirements.
With the Nano's USB converter constantly sucking power it is the least frugal device of the newer Arduinos, the pro-mini has a wealth of information on reducing sleep load power with LED and VR removed, perhaps a change in approach may be worthwhile ?

Yes I fully agree, but if Arden only have those Nano available, he can use those with extra effort to remove all those not needed current consumption IC's

@kimot said in Nano minimum voltage:

But it do NOT means with 16Mhz crystal on Arduino Nano ...

Well the AtMega328 has an option to use internal RC oscillation and hence don't need to use the 16MHZ crystal.
yes we agree that with low voltage you must use 1MHz, -> 8MHZ div8

From the link I have provided above, read chap 9.6:
Calibrated Internal RC Oscillator
By default, the Internal RC Oscillator provides an approximate 8.0MHz clock. Though voltage and temperature
dependent, this clock can be very accurately calibrated by the user. See Table 29-9 on page 313 for more
details. The device is shipped with the CKDIV8 Fuse programmed. See ”System Clock Prescaler” on page 45
for more details.
This clock may be selected as the system clock by programming the CKSEL Fuses as shown in Table 9-11. If
selected, it will operate with no external components.

And yes it's possible and maybe needed to calibrate the internal RC, that you need to test

And yes you need also to change fuse for BOD (Brown out detection) as this by default close down the ATMega328 below 2.7V
read chap 10.2: BOD Disable

@dbemowsk agree 60/40 Sn/Pb - my post have been edited to be correct

@arden said in Nano minimum voltage:

Know officially the nano needs 5v
Has anyone played with the minimum voltage you can get away with

You don't need to play around, as the first thing to do is to read the datasheet for the CPU, a nano like the other original/classic Arduino's are using AtMega328p, then you get knowledge what is possible.
Datasheet: The device operates between 1.8-5.5 volts.
and this means to bypass/remove the voltage regulator on the Nano board

http://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061A.pdf

very interesting thread to read to understand all those bloody counterfeit HW
and also how you managed to find out - and good that Mysensors sw provide a good logfile for investigating

If the proposed serial gateway wont work, then try something else, if you have a friend that also use home automation, maybe you can try to connect you gateway and sensor to his system, then you are away from your home, maybe something is disturbing your 2.4GHz communication

https://electronics.stackexchange.com/questions/1980/what-s-the-proper-soldering-iron-temperature-for-standard-031-60-40-solder

And then a comment, I think most people at home use 60/40 tin/lead (Sn/Pb) ratio
At my work it's forbidden to use Pb and then we have some leadfree solder, it's more difficult to use and REQUIRES higher temperature (Just read this as info)

You can also use airbubbles pressure sensor to determine your water level
https://playground.arduino.cc/Main/Waterlevel/
https://automationforum.in/t/what-is-a-bubbler-level-gauge/2503

@alexno
Looks very nice- do you have your own moulding machine at home?

Basically you have 2 options:

1. You are present to watch when the port goes down
2. something expensive like this: https://duckduckgo.com/?q=Safety+Light+Curtains&t=canonical&iar=images&iax=images&ia=images

@fanfan
Looks nice, and I love the idea that you spend time and knowledge to your kids
but looking at the current budget it seems that you are above the rated current consumption for the 74HC595, just so you don't wonder in case it burns when several LEDs are ON at the same time

Input clamp current, I IK (V I < 0 or V I > V CC ) ±20 mA
Output clamp current, I OK (V O < 0 or V O > V CC ) ±20 mA
Continuous output current, I O (V O = 0 to V CC ) ±35 mA
Continuous current through V CC or GND ±70 mA

Data from here:
https://www.sparkfun.com/datasheets/IC/SN74HC595.pdf

@eeichinger
Yes an old thread, but still useful.
well if you plan to run on a low voltage, you must disable BOD, else per default the 328 will switch off at 2,7V. And then you need to run 1 at MHz

@ben999
But also look careful at the smokealarm PCB, as you might be able to reuse this to ensure that you are using resonance frequency

@ben999
I guess you don't hit resonance frequency.
Why not scavenge a piezo from a smokealarm, then you you know that the circuit is made for resonance frequency.
BTW I did not write MY piezo is working at 30V, I directed to a piezo that Adafruit is using, and that uses up to 30V - just to correct that I hvae not used the pieo myself

Adafruit have this one, can you try to make your setup similar? Notice that you need to oscillate it at resonance frequency to provide loudest beep.
Piezo buzzers are used for making beeps, tones and alerts. This one is petite but loud! Drive it with 3-30V peak-to-peak square wave. To use, connect one pin to ground (either one) and the other pin to a square wave out from a timer or microcontroller. For the loudest tones, stay around 4 KHz, but works quite well from 2KHz to 10KHz. For extra loudness, you can connect both pins to a microcontroller and swap which pin is high or low ('differential drive') for double the volume.
https://www.adafruit.com/product/160
And maybe your piezo is just a quiet buzzer - try to scavenge a piezo from a smoke alarm, that will give you around 105dB, and notice they have 3 pins and not only 2 pins
https://electronics.stackexchange.com/questions/18212/whats-the-third-wire-on-a-piezo-buzzer

@zookazim
Hi as the below circuit shows, the sensor read the electricity usage form the meter via IR, the meter have a Ir LED that transmit the usage, this can be picked-up/read with a IR receiver LED/transister. this is via the electrically circuit providing the data to the Arduino, this can if the protocol is correct, convert this to useful data

https://github.com/prophetmaster/landisgyre350/blob/master/images/Arduino-IR-Collision-Detection-Module-Pin-Outs.png

not sure what you exactly are searching for, did you check here?
https://kicad.github.io/footprints/Converter_DCDC

My car uses IR for automatic wipe the windshield, light are reflected if it hit a rounded surface, if there are water drops, then less light are reflected and wiper start to clean windshield
https://en.wikipedia.org/wiki/File:Rain_sensor_en.svg

Yes it's all fine to say goodbye, but maybe you should try RFM69 as most of those NRF24L01 are fake from Chinese suppliers, and that could have given you the bad experience, and if you also use WIFI on 2.4GHZ and Bluetooth devices, then 2.4GHz is quite crowded.
I myself also live almost in a Faraday cage, forcing me to have WIFI gateway on both my groundfloor as well as have one WIFI gateway on 1 floor, with cable to both WIFI gateway. Funny enough my Zwave 868MHz devices are having good coverage in whole house (Yes maybe it's due to Zwave have mesh network (not battery devices), and my battery Mysensors have mesh disabled)