Easy/Newbie PCB for MySensors

[sincze]

@gohan Don't know. Pin3 could be used to drive the led tx without problems. It only did not work with the temp sensors. I moved the temp sensor to d2.... modified the sketch and it did not work as well. and d2 was driveing rx led. So well root cause unknown... solution: solder a new pro mini and keep the other one for different purpose.

[zboblamont]

@sincze Did you use D2+D3 on all the same devices?

[gohan]

I'd try the other digital pins too

[sincze]

@zboblamont @gohan The Sensor with the replaced Pro Mini is in production now ;-). I'll start soldering a new Easy/Newbie PCB, because once you know how to do it... it is Easy and test the individual pins with a door/window sensor.

[Barna]

Hi Sundberg84,
What could you advise for battery powering (remove led and regulator too) if I would like to use Mini 5V and measure the battery level too ?
thx

Barna

[sundberg84]

@Barna the 5v pro mini are running a 16mhz crystal as default and this needs higher voltage to be stable compred to 8mhz (3.3v pro mini).

I have never tried this so can't give much advice but I would probably take the effort of reprogramming the fuses and bootloader to a internal 1mhz and run the hardware as that (the hardware is the same on 5v except the regulator and crystal )

[gohan]

@Barna why do you want to use a 5v arduino?

[Barna]

Hi Sundberg84,
I have used this step up booster
https://www.ebay.com/itm/181612513907?rmvSB=true

but found this (2nd),
https://www.ebay.com/itm/10Pcs-Mini-2-in-1-1-8V-5V-to-3-3V-DC-Step-Down-Step-Up-Converter-Power-For-Ardu/182793323053?hash=item2a8f54c22d:g:PJMAAOSwYL9ZzAXC
It has lower noise, so I could connect the radio to the Mini. What do you think ?

[sundberg84]

@barna lower noice is better but I can not confirm this module is better. You have to try. Yes you can connect this to EasyPCB just like the first one.

[Tommas]

Hi All!

Could someone suggest me an elegant way to extend the mysx connector? SO i would like to multiple the A4 A5 pins onto another prototype board to use more I2C devices....

[sundberg84]

@tommas just add a wire on the back side to the prototyping area ? You could design a MysX daughter board as well

[Tommas]

@sundberg84

Unofrtunately i havent got the skills and free time for a daughter board.:(. But doesnt have someone else a daughterboard?:)

[Tommas]

@sundberg84

Or have you got any suggestion expansion board for arduino mini pro ? Something like this: arduino-pro-mini-undershield (but it can not buy on ebay)

[sundberg84]

@tommas how about a wire to the prototyping area ?

[dbemowsk]

@tommas you could easily take a piece of prototyping PCB like this and create your own daughter/prototyping board if you need more space than the prototyping area has.

Use a set of connectors like this to connect to the MysX connector on the easy newbie board.

[Nca78]

I have plans for MYSX connector daughter boards, maybe if you tell me more about what you are planning to use I can adapt.

[helvetian]

Hi community!
i just got to fiddle around with my new newbie pcb and i ran into some problems.
I am already quite familiar with mysensors as i have built quite a couple of different nodes which are working very well (all on bread boards or selfmade pcb boards)
No i wanted to step up a bit and bought the newbie pcb boards.
I want to have a battery powered setup. So i did solder all the parts on the board. checked my wiring many times and also checked all components. I even did check the whole pcb board if every line is ok with a multimeter.

So my problem is:
all the time i debug my node (mockup sketch) with the Arduino IDE powered by battery, stable power source etc i end up having the error TSP failed.

when i leave my set up as is (i solders headers to the board to conveniently change the components ) and only power the NRF24 seperatly i get no errors. So it must be something with my power ?
but i don't get it where exactly my problem lies.
Could somebody help me?

[sundberg84]

@helvetian - hi, sure we can help!
But it would be much easier if you described your hardware setup (picture?) and logs.
The EasyPCB is versatile so you can use it in many ways, but a wrong combination can make it not work.
Do you use a DC-DC booster? Batteries? Which jumpters did you solder? And so on...

Did you by any chance connect both batteries and ftdi Vcc at the same time?

[helvetian]

thx for your fast reply. i'm in the train right now. so i can't provide you now with any pics. as soon as possible i will do that!

I am using a battery booster (as it seems the same as you use), i have the battery jumpers connected, all the resistors and caps for the battery measurement.
It is just wired that it functions while the nrf24 is powered separately. maybe i got some bad radios?
One more question: the cap just below the booster. is this necessary to reduce the noice for the radio? might that help and if yes what size do you recommend? i didn't solder any cap yet there.

"Did you by any chance connect both batteries and ftdi Vcc at the same time?"
Yes! I did try this as well. Same results...
I should also mention i got my Arduino Pro mini battery powered hacked. So no more LED and Voltage regulator. But then again i also tried it with a untouched one.

[gohan]

I am using 2 10uF ceramic caps both on booster and radio side, so I strongly recommend to get a bunch of those as they are working better than the electrolics and can be used in many ways.

[sundberg84]

@helvetian - good, sounds like a good start.
If you have a booster + battery jumper in place this powers the radio separately. The most critical capacitor is the one close to VCC/GND on the Nrf24 radio. What value do you use here? Sometimes it helps to try higher values. I use 4,7 in normal cases but sometimes I either replace it or add in parallel a 47uF as well.

maybe i got some bad radios?

This is not uncommon... noice from the booster (also common) combined with a bad radio might do this.

One more question: the cap just below the booster. is this necessary to reduce the noice for the radio?

Yes and No - I dont have any hard evidence (there are caps on the booster itself) but I have had good results with a 0,1 cheramic cap for a node that didnt work. It doesnt hurt to add.

"Did you by any chance connect both batteries and ftdi Vcc at the same time?"
Yes! I did try this as well. Same results...

Dont do this - only 1 Vcc allowed

When you have the time, upload a picture - it will probably help us more to help you.

[helvetian]

here are some pics form my pcb board!

[sundberg84]

@helvetian looks good! Nice work.
I would start by soldering in/change capacitor on the radio and booster as mentioned. Try some other radio of you have. I have never connected the jumper for irq so just to test of nothing else works you can de-solder the irq jumper.

[helvetian]

ok. thanks for the tips and your promt assistance! such a great community!
i will try to experiment with some caps.
i tested already a couple of different radios. but maybe i will get once a decent one which will work

[gohan]

get some of these, I am very happy I got them
https://www.aliexpress.com/item/Free-shipping-100PCS-Multilayer-ceramic-capacitor-10UF-106-50V-P-5-08mm/32783039097.html

[helvetian]

@gohan
just bought them on ali. What would you recommend in the meantime till they arrive here in snowy switzerland? i got a assortement of electrolyt caps.
i got a bunch of 0.1uf ceramics. could i just solder(or test it on a breadboard) 10 of them to try out?

[gohan]

try adding first one on the booster and see what happens

[helvetian]

just a quick update.

i ran some more tests with different radios and a 10uf electroltyte cap on the booster. And some different batteries.
Heureka! It works. For now. It is running now with a 3.7v lipo battery without the voltage regulator. Does anybody know if this is safe in the long run?

[gohan]

I wouldn't do it if I were you. You are going to fry the radio

[sundberg84]

If you bypassed the booster and that works it seems like you have a booster which generates alot of noice. Try bypassing it with 2xaa and see what happens.

[helvetian]

@sundberg84 do you experience the same thing when you are using boosters? Some are better than other even tough they are the same model? Same with the radios?

[sundberg84]

@helvetian correct. I can buy a batch with 10 boosters and some works and some don't. Most can work with the right capacitors as support but a few was just impossible.

[gohan]

@helvetian when dealing with cheap Chinese stuff, you always have to consider that you may have got a poor quality product and because of this I also bought LiFePo4 batteries that run at 3.3v so no regulator needed making it easy to figure out if it is a power issue or else

[helvetian]

Thanks for clarifications

Awesome forum!

[sundberg84]

@helvetian - just so you dont miss this. A Atmega328 (Pro mini if you are using EasyPCB) can be run without a booster by reprogramming the fuses/bootloader. This is more advanced but possible. Then you can run the pro mini with a 8mhz or 1mhz internal clock down to the radio minimum 1.9v. This is a better option compared to boosters but harder to achieve.

[Nca78]

@sundberg84 said in Easy/Newbie PCB for MySensors:

@helvetian - just so you dont miss this. A Atmega328 (Pro mini if you are using EasyPCB) can be run without a booster by reprogramming the fuses/bootloader. This is more advanced but possible. Then you can run the pro mini with a 8mhz or 1mhz internal clock down to the radio minimum 1.9v. This is a better option compared to boosters but harder to achieve.

No it is not "hard". You just need to copy files in a directory, edit a text file and flash ISP sketch on a nano or uno bard. Easier than dealing with unreliable boosters

[sundberg84]

@nca78 ... can be discussed. Wiring needs to be right. It's not hard when you know what to do but it's harder compared to a working booster.

[gohan]

This post is deleted!

[sundberg84]

@gohan - sorry, didnt understand?

[wes]

I've just built a few nodes using the EasyPCB Rev 9 RFM69 Edition and I can confirm it lives up to its name - build takes only 15-20 mins, and node works first time because there is no chance of incorrectly wiring the radio. Thanks @sundberg84!

The PCB fits nicely along with 1 or 2 AA batteries into the 100x60x25 project boxes available on eBay for about $1 each:

(AA battery holder is actually about 1.5mm too long to fit - I've cut off the non-spring end of the holder, and the positive wire is held by tension between the +ve battery terminal and the side of the case. Ugly, but fine for nodes that don't get moved around. White tape is to prevent antenna from shorting against the top of the radio module.)

I have a couple of observations that might be worth considering to make the next revision even better:

• According to the MySX specification, MySX header pin 10 should be connected to Arduino pin D4, not D2 (which is already used for the radio)?
• It would be handy to have a bit more space between the voltage booster and the adjacent cap - boosters with pre-soldered right-angle headers don't fit without hiting the adjacent cap (see photo). You could free up some space for this by mounting the battery measurement resistors vertically. (There is a risk that this might cause the voltage divider circuit to pick up noise from the adjacent booster; which might cause a bit of random fluctuation in the battery voltage readings. I suppose you'd need to do some tests to see if this is actually an issue.)

• I put a few layers of insulating tape under the RFM69 so that it sits about 0.5mm clear of the PCB, to make it easier to desolder if the need ever arises (see photo). It would be nice if there were holes in the RFM69 pads so that it could optionally be mounted via 2mm male/female headers. You'd need to make a small adjustment to the antenna length if actually using headers, but otherwise I don't think this would affect the radio's performance.

• EDIT: You can surface-solder 2mm headers to the existing pads, but it ain't pretty:

• You can mount a DS18B20 in the prototyping area!! (requires wire soldered under PCB to arduino input pin)

• I think the 4k7 pullup resistor for DHTxx/DS18B20 temperature sensors should be on any pin other than D3. The only (easy-to-use) hardware interrupts on the ATMega328P are D2 and D3, and D2 is already used for the radio, so D3 should be reserved for sensors that require an interrupt (e.g. motion sensors, buttons, switches).
• In fact, the space taken up by the pullup resistor might be better used as a second prototyping area. If you bring out some arduino IO pins to this area, you could actually connect a pullup resistor to any of those IO pins. It would also be good to bring out some of the IO pins that aren't already brought out on the MySX header. Suggested layout (apologies for literally-back-of-an-envelope sketch):

Hope that's all useful / constructive.

Thanks again for designing this awesome PCB!

[dbemowsk]

@wes Really like those 3.5mm jacks you used for the temp probes. Did you get those from ebay too?

[wes]

@dbemowsk said in Easy/Newbie PCB for MySensors:

@wes Really like those 3.5mm jacks you used for the temp probes. Did you get those from ebay too?

Yes - sockets / plugs

The plugs were not great quality - screw threads were mangled so it was very difficult to screw on the backshells. I'd go for slightly more expensive ones next time. The sockets were fine.

EDIT: NB the tip and ring contacts on the socket will momentarily short out as the plug is inserted, so it's really important to wire the plugs/sockets so that this doesn't short out VCC/Ground, e.g.

• Tip: VCC
• Ring: Data
• Sleeve: Ground

Which will cause VCC/Data to short out when the plug is inserted, which is fine.

[Nca78]

@wes said in Easy/Newbie PCB for MySensors:

• According to the MySX specification, MySX header pin 10 should be connected to Arduino pin D4, not D2 (which is already used for the radio).

I think you are mixing up the MYSX pin numbering and the Arduino pin numbers.
Fourth digital pin of the MYSX connector ("D4") is clearly stated as beeing an interrupt pin, so on and ATMega328 based board it cannot be any other pin than D2 or D3.

[sundberg84]

@wes - Woaw! Thanks a million man for the great and clear feedback!
Its a great feedback on several points which I'm going to take into Rev 10!
And nice looking node you have built - very clean and professional!

• MysX, as already mentioned I think pin 10 it should be a D2 + D3. If you check out one of the MysX authors boards schematics it the same.

It would be handy to have a bit more space between the voltage booster and the adjacent cap - boosters

I have had this on my mind before but the booster I designed it for, its pins were mounted the other way around which worked out great. This is the second time I hear that part of the board needs more space and maybe I could move the voltage divider (different reasons) but I think it might be a good idea.

I put a few layers of insulating tape under the RFM69

Its a great tip - I use ESP-07 for some stuff and do the same! Easy to desolder if needed.

It would be nice if there were holes in the RFM69 pads

Consider it done.

I think the 4k7 pullup resistor for DHTxx/DS18B20 temperature sensors should be on any pin other than D3...

Pure logic - I agree, consider it done.

In fact, the space taken up by the pullup resistor

Im thinking maybe I should move the resistors for battery measurment under the Arduino Pro Mini and re-use this area as you described. Thoughs?

[wes]

@sundberg84 said in Easy/Newbie PCB for MySensors:

the booster I designed it for, its pins were mounted the other way around which worked out great.

Perhaps an even better solution would be to provide two sets of holes for the booster, so that it can fit in the designated space regardless of which way round its pins are.

@sundberg84 said in Easy/Newbie PCB for MySensors:

Im thinking maybe I should move the resistors for battery measurment under the Arduino Pro Mini

Great idea! The only consideration is clearance if soldering the Arduino directly to the PCB, but resistors should be ok - the black plastic spacers on the header pins are 2.3mm high, and typical resistors are only 2.2mm in diameter.

You could even get away with putting caps under the Arduino, if you allow enough space for the them to be laid on their side if soldering the Arduino directly to the PCB. My 0.1uF electrolytics are 4.1mm diameter, so a directly soldered Arduino would have to sit about 2mm higher than normal. Or you could use tantalum or polymer capacitors, which should be less than 2.3mm high if laid on their side (but more expensive than electrolytics).

Some further thoughts I had overnight:

• Could you please post a JPG/PNG of the schematic in the design files section? (The schematic on the description page is a bit too small to read. Thanks!)
• You could save some space by changing the REG/BAT selection from jumpers to solder bridges, which can be squeezed into a lot more places on the PCB, especially on the back. However, the REG/BAT headers are useful both as a power switch and a great place to connect a multimeter/ammeter to measure the node's current draw, so I'd be a bit sad if you did this.
• There's enough space under the RFM69 (on the back of the PCB) to mount a CR16xx battery holder. Or if you relocate the adjacent caps, there would be space for a CR20xx battery (which are cheaper, higher capacity, and easier to find).
• If you were to make the whole right hand side of the board a prototyping area (i.e. clear of components), it would be exactly the right size to mount a 1xAAA battery holder.
• If you do bring Arduino IO pins out to the prototyping area(s), it would be really useful to put solder bridges in the traces (if space permits), or at least space the traces to make it easy to cut any that aren't wanted.
• A PCB trace antenna would be really cool!

I know that's quite a wishlist, and not all those ideas are compatible with each other, or the Nrf24l01+ version of the PCB, but I hope that provides some useful inspiration nonetheless.

Thanks again @sundberg84

[gohan]

@wes pcb antenna is going to be a challenge since rfm69 come with 3 possible frequencies

[sundberg84]

@wes

Im thinking maybe I should move the resistors for battery measurment under the Arduino Pro Mini

Great idea! The only consideration is clearance if soldering the Arduino directly to the PCB, but resistors should be ok - the black plastic spacers on the header pins are 2.3mm high, and typical resistors are only 2.2mm in diameter.

Maybe a better idea is to include a SMD voltage divider on the back for advanced users and not make the current voltage divider harder to use (by putting it under the pro mini)

• Could you please post a JPG/PNG of the schematic in the design files section? (The schematic on the description page is a bit too small to read. Thanks!)

I have posted for RFM Rev9. Nrf I will post as soon as Rev 10 is developed (Using Kicad now).

• You could save some space by changing the REG/BAT selection from jumpers to solder bridges, which can be squeezed into a lot more places on the PCB, especially on the back. However, the REG/BAT headers are useful both as a power switch and a great place to connect a multimeter/ammeter to measure the node's current draw, so I'd be a bit sad if you did this.

• I will not use any smaller / smd components on the top side. All main functions have to be 2.54mm/legs.

• There's enough space under the RFM69 (on the back of the PCB) to mount a CR16xx battery holder. Or if you relocate the adjacent caps, there would be space for a CR20xx battery (which are cheaper, higher capacity, and easier to find).
  If you were to make the whole right hand side of the board a prototyping area (i.e. clear of components), it would be exactly the right size to mount a 1xAAA battery holder.

I will consider this... or maybe we can do some sort of pins for this on the prototyping area and make a tutorial.

If you do bring Arduino IO pins out to the prototyping area(s), it would be really useful to put solder bridges in the traces (if space permits), or at least space the traces to make it easy to cut any that aren't wanted.

I will consider this, but as mentioned I will not use smd bridges so space might be a problem.

A PCB trace antenna would be really cool!

• See @gohan answer.

[wes]

@gohan said in Easy/Newbie PCB for MySensors:

@wes pcb antenna is going to be a challenge since rfm69 come with 3 possible frequencies

Of course (doh)

@sundberg84 said in Easy/Newbie PCB for MySensors:

I will not use any smaller / smd components on the top side. All main functions have to be 2.54mm/legs.

Sure thing; that's a good philosophy. To be clear, by solder bridges I meant two pads separated by a very small gap that can be bridged with a bit of solder, aka solderable jumpers:

(as opposed to SMD jumpers)

For your enjoyment, here 's a timelapse of a node I built today:

Building a MySensors EasyPCB Sensor - timelapse – 02:25
— Li-Wen Yip

[sundberg84]

@wes - so cool man! Thanks!
I have had in my mind for ages to do some sort of instruction / build video to be even more Newbie friendly. Is it ok if I link to this as a good build example on openhardware?

About the solder-pads - I know about them - use them in other projects. Maybe I'm a bit over-concerned about this - I will have it in my mind as a solution.

Some initial schematics today.

[wes]

@sundberg84 said in Easy/Newbie PCB for MySensors:

Is it ok if I link to this as a good build example on openhardware?

Of course. I can share the raw JPG images too if you want.

NB I used capacitor legs as header pins on the RFM69 because the proper header pins I ordered from eBay are still in the mail.

[sundberg84]

@wes - you might have inspired me to try a instructions video myself I appreciate the jpg offer and thanks for letting me use it as a good example. Great example on how to build modular to be able to change or re-use hardware.

[sundberg84]

Im locking this thread (due to multiple threads). Please use this to discuss. https://forum.mysensors.org/topic/2740/easy-newbie-pcb-for-mysensors