RFM69 node with 5V pins

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Just to mirror our previous discussion on ebid :

Your StableNode can handle 5V on his pins and not this one, but it's only available for nrf24. It could be a nice feature to nicely integrate 5V sensors, without a flying voltage divider ;).

[yurysvirida]

5 volts digital and analog pins in the current footprint? How about 3.3V for sensor swarm 1 wire \ i2c sensors?

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Yes, 5v is needed for digital and analog pins, for me at least, but if you suggest it, you must think about the same use cases. And 3.3V for i2c, 1wire, and maybe 1 or 2 analogs (?) would be perfect.

[yurysvirida]

that concept board I was talking about AM312 PIR sensor onborad. cheaper baromtric sensor.

the case https://ru.aliexpress.com/item/1-pcs-abs-47-37-18mm-1-85-1-46-0-71-inch-box-for/599593461.html?spm=2114.10010208.1000016.1.y3PmKH&isOrigTitle=true

re: and maybe 1 or 2 analogs (?) would be perfect.

I think this will do the job https://www.arduino.cc/en/Reference/AnalogReference

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Thanks for sharing. I like this design, it can adopt nrf24 or rfm69 smd, seems very compact, and it can handle 3 and 5V! I have to admit that PIR and barometric won't be useful for me (well not now), what's the use case of this board ?

So it's supposed to complete the sensor swarm with bh1750 and si721? Still, it seems to be multipurpose too. Why don't you create boards that could be perfectly dedicated, like your sensor swarm and others with no sensors but that's up to the user to make his set ?

For the first ones you could optimize sensors placing, answer the general needs, and create specific boxes for it. For the second ones, no compromises, all places needed for pins is available, still keeping a small size and no box or software needed because that's up to the user. And that would perfectly join ( I think) the purpose of tools like NodeManager.

Anyway i would buy both kind, if they existed ;)

Not interested in 3d printed enclosures ? You won't have to adapt to the box anymore but the contrary ?

For analog : you suggest to just change the reference to EXTERNAL when 5V is needed ?

[yurysvirida]

re: change the reference

If board is 5 volts so it is better to find what is maximum analog readings when 3.3 V hits analog input. but possible to use internal reference as 1.1V. but not good to me.

re: like your sensor swarm and others with no sensors but that's up to the user to make his set ?

may be you have some link on that idea? I mean smd sensors have different footprints and I tried to imagine this kind of bread board and stuck a bit. only close resemblance to me is just pin-through breadboard instead sensor swarm. duh...

my assumption for the second board is you need RFM based board with 5 volt as small as possible, right?

re: Not interested in 3d printed enclosures ?

could not make them looking good. I've seen some specially designed for 3d printers plastic things looking great, but our efforts were really soso.

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• change the reference

So what could be the trick for a board running 5V like your stable node for example ? Use 5V reference? or 3.3V? I've been testing a PT100 sensor with this board, where you have to define the REF .If it's powered by 3.3V (on the VCC next to TX and RX) its measures are different from those measured when powered by 5V. So there's no voltage divider after this pin ?

• like your sensor swarm and others with no sensors but that's up to the user to make his set ?

I was probably not clear last time, what i was suggesting is a "pin-through breadboard instead of sensor swarm", a little like Grove shield. I agree that's less integrated than your swarm, but how could you get closer of a universal node with smd sensors ? I guess you have to add specific resistors or capacitors. Maybe the compromise would be to create several swarms that could be connected to the node (RFM69+ATmega) ?

Your assumptions are right! In fact i need both 3.3V and 5V micro board .

• 3d print

That's a real designer job ! I have a colleague who created marvelous litlle box for an ESP8266 gateway, for an Arducam, and for several nodes based on rf24. Maybe we could work something out ? As it would let you be free to choose whatever form, size, sensors placing...

[yurysvirida]

Been traveling past days and missed your message...

re: .If it's powered by 3.3V (on the VCC next to TX and RX) its measures are different from those measured when powered by 5V.

the stableNode should be powered by 5V and more to be safe from power surges with voltage regulator. If you have sensor with 3.3V power and node with 5V power, readings from input pin will be maximum of 675.

Each Volt is about ~ Arduino AnalogRead value 205. I.e. 1023 / 5 (Volts) = 204,6 3.3 * 204.6 = roughly 675.

I mean if the node is powered by 5V and sensor has 3.3 V - no need to do any AnalogReference. AnalogReference is good when sensor powered with 5 V and your node is 3.3 V (need voltage divider here).

re: "pin-through breadboard instead of sensor swarm"

ok. I will try to think about concept....

re: 3d print

Looks nice!! do you have any STL file to print it ? to see how it looks in reality.

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Don't worry, I'm not the fastest to answer too!

Thanks for the lesson, still not all clear but i will confirm this with practice and a few questions ;)

1. For the stable node, when you power it through the batt pins, what's the voltage output ? 3.7V li-po battery are not adapted ? So what would be most efficient to read 3.3V sensors and 5V sensors (not on the same node ) ? One board with the power source adapted to the sensor ? Or a board for 3.3V sensors and another for 5V sensors ?

2. We've been discussing another approach for your node, and what came out is this : could we have several sensor swarms that we choose to connect to the main ( RF + MCU ) ? It could be one with i2c, + another with analogs pin, + several combination of smd sensors.

3. The node box ( to the left in the above picture ) is based on the board made by emc2cube : https://www.openhardware.io/view/295/MySI2CNode-Node-for-I2C-devices-CR123-or-USB-powered So it may not be useful for you, but will give you an idea! There are 3 STL files, inside - outside - a kind of universal support for every boxes (still work in progress ) : https://cloud.getlarge.eu/index.php/s/chARzIjGChxqM4J

If you like the style of these boxes, you may go freely with the design of your boards and we could handle the 3D parts with open source plans. Let me know what you think about this possibility.

[yurysvirida]

re:

1. For the stable node, when you power it through the batt pins, what's the voltage output ? 3.7V li-po battery are not adapted ?

the best way is to use 3.3V LDO on the node. can you re-solder it yourself? I can send you bunch of them. then you have all settled.

re: So what would be most efficient to read 3.3V sensors and 5V sensors

3.3V board + 5V sensors - Use voltage divider between sensor and the board and analogReference(INTERNAL);

5V board + 3.3V sensors - just read the maximum value (3.3 V) and note it. Hope I am clear here))

Assume your 5V board has 5V LDO and powered with more than 5V. Assume your 3.3V board has 3.3V LDO and powered more than 3.3V

printing your boxes ))

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Hey sorry for this long delay, I decided to learn Kicad to have more efficients discussions !

I can resolder these, but don't bother, I was just curious for the answer.

So, based on our discussion, I made a board with functions I'd love to see. If you mind to take a look, it's on my github page (Cosmonode, and its extensions ). I'd like to have your opinion, and it probably will show you better what I tried to suggest these past weeks.

What about 3d printing ?

[yurysvirida]

Hi,

Boards look super nice! now I understand what you mean. congrats! How much time did it take you to design them? will you order pcbs?

re: 3d printing

I tried to print with my cheap Prussa i3 clone and had some results in the photo. I think to print them nice I need more expensive printer. My slicer settings did not allow me to print robust and simultaneously matching all parts together. If I print clean looking parts, inner shell does not go inside outer shell. But idea is for battery compartment is great. also super cool that they go inside each other? just need some tweaking here.

for exterior parts of those printed shells I was thinking to do something bumpy turning disadvantage of the imperfection into advantage... extreme case of bumpy print ))))

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Thanks! Kicad has a really nice manual so it took one day to learn it and make a few small useless boards with it. Then another day for a board much too complex at the time, so it will not go further; the node could be flashed and the battery charged at the same time with a micro USB. Finally with a simplified version, ( no parts on the bottom layer, no USB functions ) it took another day for node's and extensions design.

Yes, in fact I was so proud ( like a child ) that I quickly ordered some PCB's (and components of course), to see what it will look like, what issues could be found, how can it be upscaled .... I already think of adding nrf24 footprint, but it would be tricky on one layer...

Please take any idea you might like, I did the same by inspiring from your nodes ! I'm sure, this extension thing can really be useful for designers and users.

By the way, which software you and Koresh use for schema and PCB design?

• 3D print

That's the frustrating part! Originally the guy who designed these have a Zortrax, which prints really precisely, so he made his plans based on his printer. Because I met the same problem as you, these STL files have been adapted for an open source PLA printer (DiscoEasy200 Dagoma), in quick & dirty mode ( 0.2 mm layer, 17% filling, 60mm fill speed ).

Just so you know, sometimes with a heatgun (approx 150°C) you can adjust parts being too tight!

There's also the fixing rail behind, you can slide several parts which may be suspended, sticked, screwed... ;)

So what's the idea for that "good" bumpiness ? :) You want to add a moon surface on it too ?

PS : By the way, there's also a box with this cosmonode, but few adjustements must be made before I push it on github. ( Kicad was not enough, I also learned Freecad ).

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A cool thing with 3d printer, you can print your PCB before receiving them. Why ? Just for fun, and mostly to adjust the design your box.

[yurysvirida]

Cool cool! when you will burn your atmega chips, be careful with dualoptiboot bootloader + OTA + M25P40 chip.
Koresh posted solution for it on the MySensors. Check it. In addition, arduino code should have #define MY_OTA_FLASH_JDECID 0x2020 and boot-loader should be ready for M25P40 chip. Let me know if you need some help here.

re: 3D printing

No need to add moon there )) I will try to make it and show you later on))

re: By the way, which software you and Koresh use for schema and PCB design?

Altium designer. but I downloaded KiCad today, nice! will try to make something simple ! inspired by your 1 day learning, though!!!

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Hey; always good to trade tips !

• OTA :

You probably mentionned this topic : https://forum.mysensors.org/topic/3160/ota-flash-types-for-mysensors/44 ? I admit that i might need some help to fix dual optiboot. Maybe you have a repo with your fork ?

Components are almost all arrived so it's time to worry about that ;)

• Kicad

Have you made any tests ? Satisfied ?

[yurysvirida]

OTA :

Yes. let me know if you cannot make it working

Kicad:

)) tried. took me 2 weekends and many evenings. did some board and ordered. once ready will publish it)) it is different from altium but simpler. did you find good way to do standalone "through pins" like for "layers stitching"?

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I'm waiting these RFM69CW chip for the moment of truth ...

Nice, we could eventually work on the same boards! I'm not sure i understood your question, did you ask about vias or just holes for 2,54mm pins? It might be the second 'cause I had the same problem, in Eeschema, you have Cvpcb to associate your footprints, in it you should normally find Pin_Headers (male) and Socket_Strips (female) families. If not try to import them, as they are present in Kicad official library.