💬 Very narrow and minimal switch node

[openhardware.io]

https://www.openhardware.io/view/28/Very-narrow-and-minimal-switch-node

[hek]

Really nice @GertSanders!

[Anticimex]

Just a friendly reminder that you need to include the required files as specified in the CERN license howto for the license to actually be valid. Nothing "illegal" about it, but you are currently not "protected".

[jemish]

please write detail of how to use and what is actually function of this device.

[gyro]

@jemish if I understand right, as he says in description, it's intended for connecting 2 binary switch - for example:

• two magnetic switch or
• one magnetic switch in combination with PIR sensor

For use in let's say in security system for a true detection that someone is present.

If in the future another sensor is connected, you can update the node software over air.

Please correct me if understand this wrong.

Otherwise @GeartSanders great job as alway. I have order your battery based (no SMD) node pcb and received them yesterday. Now the fun (soldering) begins:)

[GertSanders]

@Anticimex made an effort not sure this is sufficient.

@jemish read the Description on OpenHardware.io I have tried to be complete.

@gyro You can not update the node over the air. It is too simple for that (it lacks the proper boot loader and flash memory for that). But simple nodes have their uses too, I do love my minions Have fun with the soldering !

[Anticimex]

@GertSanders To be really strict, you also need "Licensed under CERN OHL v.1.2” on your silk or visible copper layer as specified in the howto. Obviously that might be difficult on your board but that is what the howto says. But I will leave it to you to decide which license to use. If you don't really care, you can always choose to skip a license alltogether

[sundberg84]

This thred is getting off topic... but
@Anticimex You have probably seen the FAQ for Cern, but there is a question about the Cern on silk.

"So to summarise, adding the licence notice is not a requirement, but as licensor, it is one of the best ways to make it known that the hardware is Open (Source) Hardware since it may well get ‘separated’ from the Documentation in its life. The licensee does not have to add the notice on the silkscreen, however if the licensor has put it there, he may not remove it."

[Anticimex]

@sundberg84 Good point. I did not see that in the faq I read. But that's great news for those who already did tape-out.
As for the changes.txt, I just do a git log > changes.txt to generate it from the git history.

[sundberg84]

Yes - like me

[carlierd]

Very good job !!

I saw that you provide a bootloader. What specificities ?

Other (very selfish) question: next version of your not will be compatible with RFM69HW ??

David.

[GertSanders]

@carlierd The only specific thing about the boot loader is that it flashes the LED on pin D8 when starting up and it expects a transfer rate of 78600 when uploading sketches. Apart from that it is standard Optiboot 6.2 for operation at 8Mhz.

I only have and use NRF24L01+, so RFM69HW is not in my plans or tests for the moment.

Update: 15-FEB-2016
The original boot loader was wrongly compiled for 4MHz, so when you try to upload at 38400, it will fail. Uploading the boot loader at 76800 when running at 8MHz will work, but timing in the sketches will be twice as short as expected.

I replaced the original boot loader with a version compiled for 8MHz and upload speeds of 38400.

I also added a second boot loader (for version v1-1) which is made for 8Mhz operation and upload speeds of 38400. This second boot loader flashes LED on pin D6.

[carlierd]

@GertSanders I will try to modify your design to replace the NRF with a RFM69. Thanks.

[GertSanders]

Updated the design files with version 1-1. Explanation of what this version does will follow later (not that much more, but I2C extension is now an option).

[meddie]

Very nice! It would be perfect if it would get an atsha204a and a flash module.
Greets Eddie

[GertSanders]

@meddie not sure that would even fit on the board, have you seen the size?

[meddie]

@GertSanders
the PCB must be a little bit longer. But the two chips are not big. The ATSHA201A is very small its a 3 PIN smd chip, and the flash chip is 8 pin.

[GertSanders]

@meddie I try to stay within the 50mm length limit, so that we can have the boards produced in a 50x50 format. Making it longer means we need to go to a 100x100mm format, and that makes it more costly (not necessarily per board, but some people do not need +50 sensor boards).

At the moment we get 5 of these nodes within the 50x50mm limit, so a prototype run already produces 50 boards.

Anyway, I'm not exscluding this idea, I just do not have a need for it now. The minimal node is meant to be minimal, not a complete MySensors node. If you need that, there is always the Sensebender Micro (which has it all built in).

[Carl H]

@GertSanders I'm a fan of your boards. I have your 20x30mm board, AC/Capable 50x50mm board (my favorite) and now I ordered your v1.1 of your narrow board because you are agree my suggestion for I2C port with jumper

[Carl H]

@GertSanders , 1 question, you have specified 1/8w resistor... did you know if 1/4w fit on narrow board ?

[GertSanders]

@Carl H If the 1/4w resistor can fit in pads 7mm apart from each other, then should be no problem. But they need to stay flat to fit under the processor.

[jacikaas]

Hello, @GertSanders I would like to ask. How I understand it is possible to load different sketch type to this board and then I could use it like one of MySensors sketches? For example could I load MyS humidity sketch? Thanks!

[GertSanders]

@jacikaas: to program the processor, you need to remove it from the board and program it on a breadboard or another board with ftdi interface.
But you can load a sketch like the humidity sensor sketch if you add a I2C sensor like a SI7021. I plan to do just that.

[GertSanders]

The very narrow boards v1-1 have arrived

[GertSanders]

The latest member of my growing sensor family, a reedswitch sensor with wakeup from power down by change on pin 2, wakeup every 23 hours to report battery voltage, and of course a blinky light when these things happen

Just tested and found to be OK. Next board will be set up for using a I2C module (will be my smallest temperature sensor yet). Time for a glas of WestVleeteren and rest.

[carlierd]

Very nice !!
I just started learning Eagles to modify your board for RFM69 compatibility. The road will be long
Could be good also to add ATSHA204A but in a second time !

David.

[alexsh1]

@GertSanders said:

Just tested and found to be OK. Next board will be set up for using a I2C module (will be my smallest temperature sensor yet). Time for a glas of WestVleeteren and rest.

@GertSanders
Westvleteren Blonde is very nice
Can you please remind me the difference berwrrn v1 and 1-1?
I think it would be good to add FTDI connection, but the space is very limited

[GertSanders]

@alexsh1 FTDI would be nice to reprogram more easily, but in my case I have a stable sketch which is loaded 1 time, and then the node is deployed. No point in providing extra pins or using boardspace if it is only used once or twice.

I saw that @AWI mentioned pogo-pins to make connections. Also a nice idea. In any case, my node is not designed to be flexible, and after programming I want to forget it. These nodes are sitting on doors and windows and need to do 1 thing only: show status of the reed-switched that are connected to them.

But adding some pads so that pogo pins can make contact to RX, TX and !RESET would still be possible.

It will be nice to see if a RFM69 radio can be connected by @carlierd . Looking forward to some pictures

[GertSanders]

@alexsh1

The difference between v1-0 and V1-1:

V1-0:
has 4 pins connected to VCC, GND, D2, D3 (in this sequence).
LED is connected to D8

V1-1:
has 4 pins, of which 2 are fixed. Vcc and GND are at the outside (closest to board edge).
The two pins in the middle (pin1 and pin2) can be connected to two different pins each by using the solder jumper.
pin1 can be connected to SDA/A4 or to D2
pin2 can be connected to SCL/A5 or to GND
LED is connected to D6

[AWI]

@GertSanders A bit off a hassle, but I don't need pads...

[GertSanders]

@AWI very nice, where did you buy the pins ?

[AWI]

@GertSanders I used these pins. These work for me but there are many other types in the same store which could serve your needs better.

[alexsh1]

@GertSanders - my idea to use exactly for windows. I was thinking about z-wave ones, but £32 a pot is just way too expensive given I need quite a few. How do you power them?

[GertSanders]

@alexsh1 I power them similar to @m26872 , but with AAA batteries. They fit the 16x16mm cable guide by Legrand (which is a known brand for this in Belgium), available is most DIY stores.

[Dombo71]

Dear
I ordered a few...:-)
Do you have a working sketch that is using less power?
Perhaps wit a motionsensor and a DHt ore something
I hope i get you hardware working..

[alexsh1]

@Dombo71 said:

Dear
I ordered a few...:-)
Do you have a working sketch that is using less power?
Perhaps wit a motionsensor and a DHt ore something
I hope i get you hardware working..

@Dombo71
You can find a few working sketches in the 'Build' section of the website. However, don't you have an idea what it is exactly you'd like to build? I would be useful to know before throwing any sketch.

FYG DHT is by far not a favourite one for a battery use in my view. There are others - SI7120 or BME280

[GertSanders]

@Dombo71
What do you mean with "using less power"?

[GertSanders]

@Dombo71
Motion sensors are also not so low power and as mentioned before, DHT are power hungry. SI7021 is much better for low power/low voltage use.

[Dylano]

@GertSanders said:

SI7021

I hope i can make a 3 in 1 sensor
Motion / contact.
temp and humanity
Better should be a multisensor, with a lot of option so we can choose .
The examples on my sensor are most 1 sensor...

And then work on a battery[s] for a year

Thanks for the SI7021 tip..

[GertSanders]

@Dylano

This board is not meant for more then 1 function.

[alexsh1]

@Dylano Have a look at this board - this would let you program via FTDI and connect several sensors.

http://forum.mysensors.org/topic/2744/battery-based-atmega328p-sensor-no-smd

[alexsh1]

@GertSanders How snug is your enclosure? I saw @m26872 used 17x20mm for his slim node, but I was able to find in the UK 16x16mm trunking, which I think maybe a little bit small.

[GertSanders]

@alexsh1
I also use a 16x16mm cable guide and it just fits, the batteries are in batteryholders and therefor they stick out by 1mm. Without the batteryholder they fit perfectly.
The board is 13mm wide at the base which allows passing a few wires next to it. So 16x16 is ok for my narrow board.

[GertSanders]

@alexsh1

Here are some images of the very narrow node in a 16x16mm cable duct. The batteries are AAA type.

[alexsh1]

@GertSanders - Thanks for photos. I have got 16x16mm trunking and just waiting for some spare parts. Will be posting photos shortly.

[Dylano]

@GertSanders

This option with a pir...
or a magnet sensor.
What is the battery live?

[alexsh1]

@Dylano said:

@GertSanders

This option with a pir...
or a magnet sensor.

This is more a reed sensor. For PIR the size is just not right IMHO.
Given that it sleeps most of the time, the battary life should be excellent.
I do not know, maybe @GertSanders has got more comments?

[GertSanders]

@alexsh1 with a switch (reed or mechanical) i see a consumption of around 5micro amperes in sleep mode. 2 AAA should last minimum a year. We will see as my node is only started last week.

A small PIR sensor is possible, see the "small AA project" and the mini PIR example.

http://forum.mysensors.org/topic/2715/slim-node-as-a-mini-2aa-battery-pir-motion-sensor

No idea what lifetime to expect there.

[TimO]

I've just ordered a batch of these. Really cool, I can't wait to receive them. Thanks for the great work!

[Bolliebol]

YES, my first is working. More to make. In my home now: "Big brother is watching you" Placed my first at the door of the refrigerator

@GertSanders, you write:
powering something with low consumption
You can set both pins D2 and D3 of the processor to OUTPUT, do not mount the pull up resistors, do not activate the internal PullUPs, and by setting one of the pins to HIGH and the other to LOW you can power something. You will need to take care that a maximum of 20mA is consumed, as this is the recommended maximum amperage the pins of the atmega328 can drive or source.

Sure not to mount the pull up resistors. But how do de-activate the internal PullUPs, and by setting one of the pins to HIGH and the other to LOW.

Can you explain in "jip en Janneke/suske en wiske" language how to. With the help of this site I made my first one:
https://forum.mysensors.org/topic/3018/tutorial-how-to-burn-1mhz-8mhz-bootloader-using-arduino-ide-1-6-5-r5

[GertSanders]

@Bolliebol
You need to use these instructions:

void setup()
{
pinMode(2, OUTPUT);
digitalWrite(2, HIGH);
pinMode(3, OUTPUT);
digitalWrite(2, LOW);

// this makes pin 2 the "plus" side and pin 3 the "minus" side.

// Connect your low power consuming thing between these two pins as if they are battery pins.

// If you need to power off the device, just do

digitalWrite(2,LOW);

}

[NeverDie]

To anyone wanting to build this project: take note that it uses machine pin female headers to seat the mcu. Ordinary female headers won't make a good enough connection with the legs of the atmega328.

[Carl H]

Hi, I have finally receive your narrow board.. I try with a Si7021 sensor (the GY-21 ebay version) and I have no success. But with your other board, because I have your 2 other board version (ac/dc board and the small battery one) it's working with no problem. The difference I think is the first board without external crystal. After reading in forum, I think with Slim board version, i'm not the first with this problem. Did you test your board with si7021 sensor, or can you give my a clue ?? Thanks

[alexsh1]

@Carl-H did you have an error message? Providing logs would also help. Which address and library did you use for this sensor please?

[Carl H]

@alexsh1 I use the this lib: https://github.com/LowPowerLab/SI7021 My board freeze when initialize with begin function.

I can't have the error exactly because this board don't have any FTDI connection. But the same atmega328p chip with other board, it's working !! I think again is it because the board use internal oscillator.

[alexsh1]

@Carl-H if your atmega328p programmed to use the internal oscillator, I do not think this would cause a problem with Si7021.

You most likely need to assemble the same on the breadboard and connect the FTDI - I would be a simple error. Once I had a problem with Si7021 using a different address to the one in the library. Took me a while to troubleshoot.
Without logs, this is a pure guess unfortunately

[GertSanders]

@Carl-H
Did you order the latest version of the slim board ? It has solderjumpers you need to use if you want the SCL/SDA pins connected.
If there is no solderbridge on either solderpad, the D2, SDA and SCL of the atmega are not connected. This board also requires the fuses of the atmega to be set to internal oscillator as there is no external crystal.

[Carl H]

@GertSanders Yes I used the version 1.1 and yes I connect the jumper pad correctly.

After some hard test, I found the problem, is it my solder or a bad batch of SMD NRF24L01 I explain my problem, I make a good solder of the SMD NRF24L01, I put power on the board for testing it and is it working for 2-3 loop because I open the led (d6) on each loop. After 2-3 loop the board is freezing. After I check again the solder and some pin of the SMD NRF24L01+ is shorted (check with my multi-meter). I can explain why, is it my skill of soldering or a bad batch of SMD NRF24lL01+. I test with 5 different and always the same, after power it.. it will shorted some pin. I make my order on this ebay store: http://www.ebay.ca/itm/401054727893?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[GertSanders]

@Carl-H
Those modules should be OK. Soldering this radio is indeed very tricky.

[Carl H]

@GertSanders Thanks... after practice and practice and practice again... I have now 4 narrow board working with si7021 sensor... I need to put my solder tip very high and use alot of flux..

[tlustoch]

Hi, if external reset is not needed, why you do not short /RESET pin 1 directly to Vcc to avoid resets in noisy environments?

[tlustoch]

Another question: Is OTA sketch upload possible?

[GertSanders]

@tlustoch
Good point, will add that to version 1.2 (if I ever find the time :-))

[GertSanders]

@tlustoch
Not possible as there is no flash memory on the board. It was never the intention to update these nodes after their initial programming.

[tlustoch]

@GertSanders
have you considered https://www.mysensors.org/about/ota MYSBootloader? It is announced to work without flash.

[GertSanders]

@tlustoch
The node is a very simple one. So I never considered boot loaders, as the node would not need changing sketches during it's lifetime. I have boot loading functionality on my other designs, this one is a minimal board. Any extra chip would beat the purpose of the word "minimal".
It's a dumb node for a reason