💬 MySensors Stable Node

[Slorf]

@Koresh

Found the smd quartz crystals

Alex

[Koresh]

@Slorf I've left the package field in bom blank, so you can use any crystal you have. All components on the board are smd, so crystal should be smd too if you have it. But it may be difficult to place smd crystal as Q2 (too small area) and I've placed holes. I have both SMD and THD crystals but I will put holes in Q1 crystal pads in the next version too. Now you can simply mount THD crystal on the pads, it's not difficult.

@Slorf said:

Would it be possible to mount something like this on the pcb?

It's possible. But I want this board to be as compact as possible.

@ahmedadelhosni said:

Great board.
Did you test the performance ? Like number of recieved packets per second ?

Thanks. I've tested stability (for some months without troubles in typical applications) and RF range. I think it doesn't make sense to test performance with low performance mcu, but you can propose the sketch and I test with it.

[Slorf]

@Koresh

I have both versions ( SMD and THD ) crystals on order with aliexpress now

As for the LDO regulators, I will wait for the PCB's to arrive before making assumptions

Now I have to wait some weeks before everything arrives ........and then my first smd soldering experience !

Alex

[Slorf]

@Koresh

I got as reply from dirtypcb's, they changed it to 1.6 mm

Alex

[fisher]

Hi,
Very nice project. Do you have a plan to sell assembled piece of the boards?
Soldering such small SMD is out of my skills

[Koresh]

@fisher Thanks. I'm looking for good PCBA service.

[fisher]

@Koresh I'm looking forward. What do you think, what will be the price of a assembled piece?

[Koresh]

@fisher The production of the first small batch is underway (manual mounting). So I wil have 20 boards for test next week. I will provide price estimate in a week.

[GertSanders]

@Koresh post pictures please

[flozsc]

Hi @Koresh,
Sorry if this is a dumb question but I'm new to this. What's the minimum voltage to power this board? Is it the 1.9V from the NRF?
I'm thinking of building a node with this using a LiPo battery with a protected TP4056 charging module.
If me idea isn't impossible I'd be highly interested to buy some assembled units of this PCB.
Thanks!

[Koresh]

@flozsc
Hi. Minimum operating voltage depends on clock frequency. Boards contain standard 16MHz crystal oscillator to full pro mini compatibility. If you use default bootloader and 16Mhz clock frequency, the board will work with a voltage above 2.7v (on the verge of stability). But you can use internal oscillator (custom arduino boards settings, for example 8MHz or 1MHz for lowerst operating voltage) with some limitations (like slower serial). In this case operating voltage should be above 2--2.1v (do not forget a little dropout of LDO regulator).

[flozsc]

@Koresh Thanks for your quick reply.
Sleeping sometimes helps. After thinking over it again, I think I'll prepend a step-up converter to 5V behind the battery as most sensors at least require 3.3V or even 5V...
Looking forward to your update on the 20 test boards!

[yury]

So far betatests for two modules soldered manually two weeks ago are good. I was using two analog inputs and 5 digital outputs. Radio is rock stable also.

[fifipil909]

Impressive !!
did you reflow the board, or did you REALLY manually solder the nrf24l chip with an iron ???

[Koresh]

@fifipil909 Thanks.
I've soldered these boards using simple soldering iron and hot air fan (lukey 702).

[Koresh]

First small batch is completed

[scalz]

excellent

[Slorf]

Nice !!!

I am still waiting for some parts to arrive from china

Alex

[ahmedadelhosni]

Wow ! I really like the color and design.
Waiting for alpha testing of the nrf chip.
Is soldering it more difficult than soldering the atmega as they are not the same package type ?

[robosensor]

@Koresh what about price for assembled boards?

[Koresh]

@robosensor So far 9-10$ for each board. Small batch and not mass production soldering... Negotiating smd services for PCBA. Hope to reduce costs by $2 final. Will see what happens.

[yury]

@ahmedadelhosni said:

Is soldering it more difficult than soldering the atmega as they are not the same package type ?

3 steps process:

1. tin-plating the board contacts
2. tin-plating the chip contacts
3. apply flux-gel and place chip on the board and heat it with soldering Heat Blower - pre-heat-wait-heat-wait . Like standard soldering profile http://www.renesas.eu/products/lead/specific_info/rt/heatproof/index.jsp .

also need to have a good ayes ))) the flux-gel should be the one you do not have to remove after.

[Sander Teunissen]

You make some... I'll buy some... great work!

[yury]

Alfa testing:

Checking radios as various nodes. Currently working as 2 relay nodes, DHT 22 temperature node and gateway.
All is good . Range 1-2 meters less than NRF24 with big antenna in apartment surrounding.
Digital pins cheeked like in the video: https://youtu.be/00fy9amZnt4
Analog pins tested with generic arduino light sensor. So radios and pins are OK.

[yury]

@Sander-Teunissen said:

You make some... I'll buy some... great work!

So far still negotiating\finding reliable PCBA. First batch of 17 boards Koresh and me we were not impressed.

[Sander Stolk]

Keep me posted!
Will order when board comes soldered and ready to use!

[GertSanders]

Congratulations !!! Best hardware project indeed !

[shabba]

I would be all over this (would get a dozen!) if using RF69. Should be handy enough to modify? I better start watching those KiCad tutorials!

[Koresh]

@GertSanders Thanks!

@shabba I've almosted completed new ultrasmall radionode based on rfm69. I'am very busy now but I hope to finish all tests in a week. I will post board asap

[scalz]

@Koresh wow looks promising I can't wait!!! I thought that sub Ghz antenna is bigger than 2.4ghz??

[shabba]

I would think we would solder on out own antenna.

[scalz]

oh maybe I didn't understand well, I thought that semtech ic (rfm69) would be onboard?? because if we wire our antenna, I don't see well why not use rfm69 module instead. In case of pcb antenna trace, ic onboard makes more sense imho. but maybe I'm wrong..I thought to give a try to this sometimes ago but had this reflexion,..and good design of pcb antenna trace for 433-915mhz is a lot bigger than 2.4ghz nrf. and smaller trace, lower range..+ need to be tuned for each design (in theory, I'm not expert)
that's cool because koresh is skilled at this lot of thing to learn! so I can't wait to see or try one board!

[Slorf]

@Koresh

Hi,

I got all the parts, but I think the NRF24L01 is the normal version and not the + version, there is no + to be found on the chip.

Would the older NRF24L01 ( without plus ) work on the board ?, or do I have to use the R1 resistor ?
( Resistor 1M ( which package size ) - unnecessary element (R1 can be mounted for backward compatibility with nRF24L01, nevermind)

Alex

[Koresh]

@Slorf It depends on crystal. If oscillator starts and works correctly some days you can omit it.

[Slorf]

@Koresh

Ermm... how do I know it works correctly ?, and if it doesn't work correctly which 1M resistor do I have to use ?

Thanks for your help !!!

Alex

[Koresh]

@Slorf NRF oscillator can work or not (or could stop after some time). If problems appear use any 1m resistor (0402 or 0603 if you can solder it). Do not worry. It is the last stage (after nrf soldering and atmega programming).
Can you provide link to your nrf chip(where you buy it)? I want to check it.

[Slorf]

@Koresh

Sorry for the late reply, our second son was born just 2 weeks ago.... no sleep anymore

It looks like this one, except mines it labelled: 0935VI, the one on the link 0935VJ

http://www.aliexpress.com/store/product/NRF24L01-QFN20-24L01-SMD-chip-new-original-SDQYS/1823911_32468479303.html

[sundberg84]

@Slorf said:

@Koresh
our second son was born just 2 weeks ago.... no sleep anymore

Congrats!!!

[yury]

@Slorf said:

reply

Congrats and enjoy ))

[Sander Teunissen]

@koresh Just created a light sensor from one of the boards I bought from you. It works great !
I had to do some tweaking with the serial monitor speed from my arduino IDE (I had to double the speed which was set in the code or something)
I also had to press the reset button just before uploading of the sketch started.
Apart from that: Great !
Thanks !

[Koresh]

@Sander-Teunissen
Thanks to your responce.
I'm sorry to hear you faced some hardware problem. Of course the board must restart itself. It may be couse of low quality of mounting first boards or it was damaged during delivery
May be you used incorrect usb-ttl converters boards without correct dtr line? I faced them year ago.. it was bad surprise )

[Sander Teunissen]

@Koresh No problems. I am happy working with them.

[Sander Teunissen]

@Koresh I guess I already know the answer, but this board works with 3.3 volts ? If I want to connect something like this:
https://www.mysensors.org/build/motion ,which works only on 5V I'd need to add a step up converter ?

Sander.

[Koresh]

@Sander-Teunissen said:

@Koresh I guess I already know the answer, but this board works with 3.3 volts ? If I want to connect something like this:
https://www.mysensors.org/build/motion ,which works only on 5V I'd need to add a step up converter ?

Sander.

Board contains two 3.3v LDO. You can change one of them to 5v (do not forget check schematic).

[hensing]

@Sander-Teunissen you can modify the motion sensor to work on 3.3V (see http://www.instructables.com/id/Convert-a-5v-PIR-Motion-Sensor-to-33v-for-ESP8266/)

[hensing]

@Koresh can you give us an ETA of the sensor? I'm looking forward to buy some

[Tigroenot]

Hi,
I aasembled your node, but the radio chip version is not the + one. After burning the MYS bootloader is prints the debug in serial:
60110 TSM:FAIL:RE-INIT
60112 TSM:INIT
60119 !TSM:INIT:TSP FAIL
60123 TSM:FAIL:CNT=7
60125 TSM:FAIL:PDT

Any suggestions?

[Koresh]

@Tigroenot said:

Hi,
I aasembled your node, but the radio chip version is not the + one. After burning the MYS bootloader is prints the debug in serial:
60110 TSM:FAIL:RE-INIT
60112 TSM:INIT
60119 !TSM:INIT:TSP FAIL
60123 TSM:FAIL:CNT=7
60125 TSM:FAIL:PDT

Any suggestions?

For not the + version you should mount 1M resistor (R21). And check all soldering points of course.

[Tigroenot]

I checked everything twice of course. I don't have 0402 1M resistor, the smallest I have is 0805

[Koresh]

@Tigroenot said:

I checked everything twice of course. I don't have 0402 1M resistor, the smallest I have is 0805

You can easily solder THD resistor in parallel with Q2

[Tigroenot]

@Koresh Did that. No luck.

0 MCO:BGN:INIT NODE,CP=RNNNA--,VER=2.1.0-beta
4 TSM:INIT
4 TSF:WUR:MS=0
12 !TSM:INIT:TSP FAIL
14 TSM:FAIL:CNT=1
16 TSM:FAIL:PDT

[Tigroenot]

Allright, I have replaced the nrf chips to those with + and... that was it, everything is working very well now
Here they are, freshly handmade

[Koresh]

@Tigroenot
I'm really happy to see your success with these boards. Congratulations!

[qqlapraline]

Very nice design ! I wish it was available for sale !

I have a question, though. Would it make sense to mutualize the Crystal between the NRF and the Atmel ?

[Koresh]

@qqlapraline Thanks for your attention to this project. A small batch of these boards is ready. Boards are under tests (individually) and almost ready for sale. Unfortunatelly I have "small" technical troubles with ebay but hope to solve them soon. Otherwise you will be able to buy them via paypal directly soon

[qqlapraline]

@qqlapraline said in MySensors Stable Node:

I have a question, though. Would it make sense to mutualize the Crystal between the NRF and the Atmel ?

(I love to quote myself )

[Koresh]

@qqlapraline said in MySensors Stable Node:

@qqlapraline said in MySensors Stable Node:

I have a question, though. Would it make sense to mutualize the Crystal between the NRF and the Atmel ?

(I love to quote myself )

I saw your question the first time, but it is a relatively hard question so I read documentation before writing the answer. I think this is a not good idea, very many inconsistencies. First, NRF24L01+ chip has a requirement:

Input crystal amplitude and current consumption
The input signal should not have amplitudes exceeding any rail voltage. Exceeding rail voltage excites the
ESD structure and consequently, the radio performance degrades below specification. You must use an
external DC block if you are testing the nRF24L01+ with a reference source that has no DC offset (which is
usual with a RF source).

If you want to be able to share atmega's crystal you must use Full Swing Crystal Oscillator mode (by default arduino uses Low Power Crystal Oscillator mode). You can set this mode without any problems via fuses, but in this case you can't power atmega from 5V (according nrf24L01+ requirement).

However in this case you can't use 16Mhz crystal because 3.3v/16Mhz is overclocked mode for the atmega 328p (I do not say your device will not work, I say atmel do not garantee stability in this case)

As you can see on the latest photo, I didn't solder atmega328p crystals at all and the chip uses an internal oscillator and is powered from 5V

[Koresh]

Unfortunately I can't open my ebay shop right now. While I'm trying to open it, you can buy this board here: https://www.ebid.net/eu/for-sale/arduino-ide-compatible-controller-with-the-nordic-nrf24l01-radio-transceiver-156695123.htm

[mfalkvidd]

@koresh is it still possible to purchase this board? The ebid link doesn't work anymore.

[deepak]

@koresh is it still available for purchase? I tried the link that you posted i couldn't find there

[reinhold]

I'm wondering what the minimum input voltage is. The description only says max. 6.5V input voltage from the battery, but does not say what the minimum is. Both the nrf24l01+ as well as the atmega328P work with 3.3V, so if I use three AA batteries, that should be fine, right? I suppose using two AA batteries is not enough?