💬 Easy/Newbie PCB for MySensors

[fisher]

@sundberg84: I have plan to use your pcb to build ethernet gateway, thus I want to use NRF24L01+ radio with external antenna. In this case it's more than recommended to use external power to supply the radio as pro mini has not enough juice to feed radio properly. Could you please give me some hint how to do it in most elegant way? I think it should be enough to do not solder radio's vcc and gnd pins to pcb, but to connect external power supply to these pins with hardsoldered capacitor. What do you think?

[sundberg84]

@fisher - that is exactly what I did... i made a external "powerpcb" which i could connect the radio to and the node (Arduino + Ethern module) to. This way I didnt feed the radio from the arduino. Be sure to use a voltage regulator with a good ampere output.

Check this: https://www.openhardware.io/view/207/Mysensors-20-ethernet-gateway-W5100-build

[fisher]

@sundberg84: thx for the quick response. I saw your post with external ethernet gateway but I'd like to avoid use of jumper wires and use your newbie psb instead

[sundberg84]

@fisher - well, the only option then is to use a 3.3v arduino on my PCB and BAT jumper. Then make sure you have a steady 3.3v on PWR on the PCB. If you have any units (like ethernet module?) that needs 5v you need a step up for this... i guess there are many ways to solve this but I have not tried them so you need to experiment a little.

[fisher]

@sundberg84: I think I have to abandon my idea to use Newbie PCB as there is slightly different wiring required for connecting w5100 module. I will solder it on prototype board instead. Thanks for your help

[FotoFieber]

@sundberg84
I really like this design. Do you have plans to make a version for the RFM69W radio? Shouldn't be to difficult but with the free version of eagle, I can't edit your design. :unamused:

[sundberg84]

@FotoFieber - that shouldnt be any problem editing. Do you try to open the gerber files, you need to open .sch and .brd

[dbemowsk]

So I have one more flaw to point out in the board that I didn't notice before. I also have a question regarding powering the nano. I'll start with the problem and this is for @sundberg84 . Some weeks back I posted some suggestions and differences that I noticed in the revisions of the boards. This was the pic:

When I posted that, you noted that for the capacitors, the G denotes ground. If you look at the blue board on the right which is the one that I have, you have the G marked on the left leg of the capacitor. If you measure continuity from that pin to the large ground tab for incoming power, you will notice that that is not ground. The one on the right is. Since I got the boards, I have always teeted for continuity for my ground legs, so I haven't had any issues, but for a newbie, which is what the board is geared toward, there could be issues.

Now on to my question regarding power. So I am building another node and I am using the 5 volt version of a Recom power module .
Seeing that this is a 5 volt output, I would think I should be able to go directly to the 5 volt in on the nano, but what is the best way to wire this if I am using a screw terminal connector to bring my power in? The RAW power pad goes to the regulator input on the nano, and the PWR pad goes to the battery booster which I am not using. I would also guess that I would need to jumper the BAT pads. Would I then too want to remove the regulator from the nano, or won't that matter?

Any help is appreciated.

[sundberg84]

@dbemowsk - thanks for your unput! I have checked my project and changed the G label.
I will also make an notise on openhardware!

You should be able to use that just fine as power. Most people here use HLK-PM01 but this might be a great addition! (Havent seen it before).
Check this thread out: https://forum.mysensors.org/topic/1607/safe-in-wall-ac-to-dc-transformers. You should connect it to PWR and GND with REG jumper short.

[Nca78]

@sundberg84 said:
this might be a great addition! (Havent seen it before).

Unfortunately it's not the same price range as HLK with 12$95 from all suppliers linked from their website.
Could still have been nice if it had "physical" advantages compared to HLK but it's bigger and with lower power.
So it's got the safety of a German product left, but HLK is safe enough provided we get a genuine one.

Interesting part is the recommended circuit which is similar to the one suggested here for the HLK with input fuse, varistor for use with 230V source and optionnal output capacitor to reduce ripple. No temperature fuse but I suppose with bigger size, lower power and higher quality components it's getting really overkill.

[dbemowsk]

I ended up ordering 3 of these. I got them from this site. It wasn't till after I ordered them that I saw a post on here about the HLK-PM01 modules. I see the better advantages of the HLK series, cost being the big one, and will order these in the future as needed, but I am just trying to use up the 3 of these that I have.

I have another project I am working on where I might order some HLK-PM12 modules. I ended up getting a lot of 10 - 12 or 24 volt relay modules for free that I figure I can use in some projects. I wish they were 5 volt, but it's hard to argue with FREE.

[fabix68]

Hello,
I'm using the temperature sensor (DS18B20) on a card v8.
Ok if I use a 18650 battery, if I use a CR2032 coin battery, the sensor does not work.
I have to make some adjustments?

[dbemowsk]

@fabix68 Your problem might be in the fact that the 18650 battery is a 3.7 volt battery, where the CR2032 is only a 3 volt. The extra 0.7 volts will make all the difference. If you use a CR2032, there are a few things you want to do. The first thing is that you need a battery booster. This will boost your power from 3 volts to the needed 3.3 for the nano and the radio. Next is to remove the LED from your nano. This will put unnecessary load on your battery and drain it much faster. You may even want to remove the regulator from the nano.

[fabix68]

I'm already using a booster to the battery and removed led and regulator. I partially solved by inserting in parallel to battery a 10mF capacitor

[sundberg84]

What are your setup @fabix68 ? If you are using a 3.3v arudino straight on it will not work.
Please describe your setup and hardware and not only your battery,

[fabix68]

I'm using Arduino mini pro 3.3v to which I removed led and regulator, battery boster and tamper on batt.
I attach the photo

[sundberg84]

@fabix68 should work just fine.
Whats your issue? Any serial output?

[fabix68]

Now, with the capacitor on the VCC, it seems to work, even if the range is smaller. It will be to evaluate the battery life

[Nca78]

Hello, don't waste your CR2032 yet, as it is now you will be lucky to last a few days ...

CR2032 and other lithium cells with the same chemistry have a strong internal resistance. It means the more current you draw from them, the more energy you will waste because of this internal resistance. It makes the voltage drop and it means your battery booster will need more and more current to maintain the output voltage = vicious circle with more and more energy wasted.

Your solution is not to add a battery booster but to use another sensor that will be able to run at low voltage: BMP180/BMP280/BME280 or SHT21/SI7021. They have a very low power consumption (unlike ds18) and will accept Vcc voltage below 2V. I would suggest the SHT21/SI7021 as it's easier to use and will go in sleep mode between measurements without any action from you.

Without battery booster you will also have a much increased range as the booster generates a lot of noise that perturbates the radio.
You will also need to:

• add a big capacitor (at least 100µF) in parallel with the battery to ease out the current peaks
• remove the voltage regulator as it's still on your pro mini at the moment
• adapt your sketch to sleep (with 200ms you should be ok) between all consecutive radio calls. Don't forget to do it in the presentation method as it's the most sensible part, before it's called the library has already done many radio calls that made your battery voltage drop. You should begin the presentation method with a sleep.
• update the fuses on your pro mini to remove the BOD which is by default at 2.7V and will limit the total power you will get from the battery
• use a brand name cell, the cheap chinese no-name cells will have much lower real capacity available, voltage will drop much faster.

[fabix68]

@Nca78 said:

SHT21

Nca78 thanks for the reply.
I did not know the SHT21 sensor, it looks like a good alternative also DHT22.
I've already added a capacitor and view the trace output with the oscilloscope, it is clean, why not explain the decrease in range.
With regard to the program, has been provided for the sending of data every 5 minutes, if it changes from the previous value, to then return to sleep.
I never tried to change the fuse on the PRO. I believe that this is the solution. Run it at minimum frequency, remove the BDO so you can also remove the battery booster.