Everything nRF52840

[NeverDie]

@scalz , If it's an either/or choice, why would anyone not pick 802.15.4? It's a rock solid IEEE standard that has been thoroughly vetted because it has been used for a long time already. Especially if the hardware itself directly supports it... it has intrinsic efficiencies.

The only reason I can see for not picking it would be the difference in transmit rate. At least on this chip, 802.15.4 won't be doing 1mbps or 2mbps, but only 250kbps. So, there is an argument for using mysensors at those higher transmit rates, and perhaps switching to 802.15.4 at the lower rate. Also, there would still be a need for something to manage that.

[scalz]

@NeverDie
of course I'm not saying to not use 15.4. I just meant it's redundant with MySensors.
It's just like if you were on a controller forum, says openhab, and were doing ads/howtos about another controller e.g. domoticz. It's free to talk about this, but still a bit off MySensors topic.
MySensors is an arduino library. That's the big difference with using others more "technical" frameworks/ide..

So it's more than just a bitrate question (a bit overhead to switch bitrates the way you said, especially with 2.4g, maybe you would gain some range but not that much indoor, depends on the wall absorption which can be huge for this band, see excel sheet..)

Choices so far are simple:

• MySensors + Arduino : easier to get started for educational, non-programmers etc. Not IP based. Suppport (not complete) for different mcus. Connectors with controllers (openhab, domoticz etc).
• BLE + Arduino (not complete cores for all mcus).
• others stack (15.4 etc) + Arduino. Not complete core for all mcus. Not as complete as MySensors with all connectors. Often code are old. More technical framework than MySensors. Less easy for non-programmer/noob
• others stacks + others non-Arduino toolchains. The most technical from a newbie point of view for coding (you need to know C in a better way than using Arduino + examples). But in this case, you get better mcu support for using features.

Maybe I'm mising a case??

[NeverDie]

The code size generated by SES for a "hello world" is 11KB, versus more like 430KB for mbed, so, I suppose, yet another reason to switchover to SES. And that's 11KB non-optimized. If I turn on the optimized settings, it should be smaller.

[scalz]

I think it's because there is also mbedOS included, and with SES there isn't any (rtos) for simple hello world.

[scalz]

still 430KB is a lot I agree. compared to MySensors stack! (not comparable, mysensors isn't an OS :) )

[monte]

@scalz haven't you noticed that mysensors' community which is represented mostly by this forum has become more than just an arduino library? People share on this forum many projects that has only mediate connection to mysensors, if any. And many of users of the library in it's current form have outgrowing some of it's limitations, so naturally they will try to find a solution to overcome them and then share with others on this forum. I don't see nothing wrong for mysensors platform to evolve and adopt modern standards and/or protocols. And even if 15.4 is not suitable or just a replacement of mysensors protocol I think there are people here that will find it useful to read about it. Correct me if I'm wrong but there is no rule against discussing other protocols than mysensors on this forum.

[NeverDie]

Anyone here tried Tag-Connect? It looks like a convenient way to interface to your modules for uploading:
http://www.microchip.com/Developmenttools/ProductDetails/TC2030-MCP-NL#additional-summary

Accono is using it to program their nrf52 modules: http://aconno.de/acn52832/

It's not clear to me whether you need to hold it against the module while doing the programming, or whether some of the pins somehow grab on to the pcb so that you don't have manually hold it up against the board while doing the programming.

[mfalkvidd]

@neverdie it was discussed in https://forum.mysensors.org/post/80266

[scalz]

@NeverDie I think you need to hold it, but it looks there is "coded" holes/slots for helping and correct positioning.

@monte
@monte said in Everything nRF52840:

haven't you noticed that mysensors' community which is represented mostly by this forum has become more than just an arduino library?

Hmm, I haven't.. so what's more? Has MySensors been forked to another platform?

@monte said in Everything nRF52840:

People share on this forum many projects that has only mediate connection to mysensors, if any. And many of users of the library in it's current form have outgrowing some of it's limitations, so naturally they will try to find a solution to overcome them and then share with others on this forum.

I'm not the last on bleeding edge, but I didn't notice many mediate connections..Which limitations have been hacked? maybe on the forum, not same on git I think. Thx to PR contributors. But apart from mysensors team, especially one very active contributor that we can thx ;) it's rather rare.

@monte said in Everything nRF52840:

I don't see nothing wrong for mysensors platform to evolve and adopt modern standards and/or protocols. And even if 15.4 is not suitable or just a replacement of mysensors protocol

Not in scope and not supported by mysensors team to switch to a standard, as mysensors is still about its own stack. It's like if you wanted to mix zigbee&mysensors logics (doesn't make sense). So 15.4 is a replacement. Maybe read about it. I'm telling this because I played and playing with 15.4+another mcu, and comparing stacks.. whether switching stack or not. If not, what could be improved, logics to add to mysensors etc.

@monte said in Everything nRF52840:

I think there are people here that will find it useful to read about it. Correct me if I'm wrong but there is no rule against discussing other protocols than mysensors on this forum.

you're right. no rule on this, free to talk. But I preferred to be precise for newcomers who may get confused when reading about nrf52840 in mysensors, that there is no support from team for others stacks, and non-arduino.
Lot of "noobs" don't know what means a rf stack exactly, what logics inside etc, they simply want to use MySensors because it's easy to use, especially when non former dev. That's what would expect someone discovering nrf52840 is supported in MySensors. So this gets completely confusing, external toolchains and using others rf stacks etc.. might end in hundreds of posts with just a few mysensors relevant infos (good luck for newcomers)

wasting my time, I won't disturbe your experiments anymore ;)
Good luck and feel free to improve MySensors of course!

[heinzv]

@scalz I think you're right to some extent if the full Zigbee stack is used.
On the othe hand, my understanding was, that mysensors provides more than an RF protocol and it supports already more than one protocol (nRF24, RFM60, RFM95/LoRa) and also partially other MCU's not just the default Arduino's e.g. ESP32 - but not for battery powered nodes. It also support a couple of sensors, voltage etc.
For battery powered sensors, I have only seen only full support for the Atmega 328p and that is for me a big limitation, as it has a couple of HW limitations such as Flash/RAM etc. and I got stuck as I want to use battery powered sensors with a low power display like ePaper.
Looking for alternatives brought up the discussion on MCU alternatives which are very engergy efficient and dont have that limitations. The nRF5 is in my eyes a good alternative with either the bluetooth, ZigBee protocoll or even if both do not provide the required range, I would just use them with a RFM95 LoRa module (why not?) it will then just replace the MCU and not the radio.
The mainy question is still open: Will there be a "full" mySensors project support for another MCU like the nRF5 or will it become another project (ZigBee, Bluetooth etc.).

@NeverDie In any case, I appreciate the work done by you, because I see the nRF5 currentyl as the most promising platform for low engergy sensor nodes. I also like the ESP32 and will continue using them, but they are complementary.
BTW: I have ordered 5 dongles via Mouser.at at (10€) with no shipping cost (above 50€, thus the 5 x 10€ order).
I'll also get my nrf52832 min Breakout-PCB's soon (https://www.openhardware.io/view/586/E73-2G4M04S-Breakout)

[scalz]

@heinzv
what do you mean by full zigbee vs incomplete zigbee then ? :)
a rf transceiver+some PHY settings VS an rf stack/framework. not the same. MySensors, zigbee, ble etc are stacks (software logics with different layers) that can run on different mcus/socs
MySensors used in non-arduino platform? which one? (esp32 idf is included in arduino, and you can add arduino module in esp-idf but that's all.. still arduino)
For the moment there are still conflicts in nrf5 hw resources for ble+mysensors.
d00616 started some work for nrf5 support, but it's not finished yet, and as usual team members do this in their very limited spare time. It's not in plan of MySensors (others members can correct me) to switch to a different stack
Sorry to not have a better answer, but it's hard to say

[heinzv]

@scalz "Full Zigbee Stack": Maybe my phrasing was not ideal, I wanted to say: if we use not only the IEEE802.15.4 Standard but also the complete stack with ZigBee.

I know that mySensors is done by (most likely a few) people in their spare time and adding a new HW stack is extra work which is not just initial work but also remaining maintenance effort. On the other hand, isn't that also the intention of a community project to discussing new possibilities and significant improvement potentials and having experts and enganged people providing pros, cons, inpust (thus also your inputs are important :-)

[scalz]

@heinzv
oki ;)
that's what I meant. your pic shows it. Mysensors is already "full" stack with different layers, and afaik it's not in plan to replace its PHY+MAC layers by 15.4 . This would imply lot of work too and most of features are already present except slotted time rf which needs quite some work..
And changing these layers won't solve nrf5 resources, softdevice accessibility in arduino.
The others solutions

• d00616 work for mysensors : help to fix issues and finish the code
• fork mysensors to another non arduino platform supporting these stacks -> lot of work non supported by mysensors team (and still redundant, worth the effort? as you could directly use your favorite stack)

Like you I tried a lot of different roads too (I'm not new on the bleeding edge like I said)..full of dilemmas, no perfect solution, still working on it!

[heinzv]

@scalz just let me/us know or please share your findings.
I'm also exploring different roads for different cases. Not just MCU, radios, sensors, displays (TFT, LCD, ePaper) etc.
So far I've got some overview on the possibilities and limitations.
I'm quite satsified with the ESP family (8266/8285 and ESP32), but I see also the limitations of the Atmega families as well as the old STM32 families.
I like the LoRa radio as best option for long range and energy efficiency use cases, but see the potential of BLE 5.0 and ZigBee but have not yet experience with it and I'm at the beginning of the nRF5x learning, but it looks at least promising.
Any other option on the radar? ... I'll follow your inputs/discussions and of course observe the market as well by myself ...

[NeverDie]

Although it's hard to predict the future, I'd wager that Bluetooth 5 will greatly overshadow 802.15.4 when it comes to wireless sensors. Why do I say that? Because Bluetooth 5 is already included in some of the leading phones: https://www.gizbot.com/mobile/features/10-latest-smartphones-which-come-with-bluetooth-5-0-to-buy-in-inida-2018-047304.html

For instance, I have a Samsung Galaxy S8 phone, and up until just now I wasn't even aware that it actually contains Bluetooth 5. Does that mean my phone can communicate with a Nordic nRF52840 using the 125kbps long range settings? I don't know, but I'm now curious to find out. Anyone know?

According to Nordic, the 500kbps mode will have twice the range of the 1mbps datarate, and the 125kbps datarate will have 4x the range of the 1mbps datarate:

I guess they're comparing it to the 1mbps proprietary mode of the same radio? Part of the reason for the 2x or 4x range increase can be attributed to the coding gain, which, AFAIK, the 250kbps 802.15.4 mode doesn't have. Unfortunately, the article doesn't say what kind of range increase to expect from the 802.15.4 mode, but I'm guessing (?) it will not be a lot. Maybe, what, 10% or 20% better? Any guesses?

But range of the 125kbps mode should be even more impressive if comparing against the nRF24L01, which has a link budget of 86dbm:

https://www.eetimes.com/document.asp?doc_id=1276396&page_number=2
as compared to 111dbm for the 125kbps mode of the nRF52840 (as quoted by the same Nordic blog as above). Part of that is from the greater Tx power and receive sensitivity of the nRF52840. In the end, all those details get reduced to a single link budget number, which is apparently how a proper comparison is made.

[Edit: https://devzone.nordicsemi.com/b/blog/posts/taking-a-deeper-dive-into-bluetooth-5]

[heinzv]

@NeverDie I also own a Galaxy S8 and interested in that study.
I especially like the idea to have a very energy efficient MCU which contains already a very energy efficient radio. That saves a lot of energy in total, soldering, wiring, complexity of multi chip handling (sleep, wake, sync) and saves also space (makes PCB's and devices smaller).
If the range is sufficent and we get the development environment satisfying established, what else are we missing?
Price and MCU performance is also ok, Flash and RAM is ok. Availability of internal peripheral and sleep/wakeup behaviour is ok. The only small drawback I've seen is that there is no internal EEPROM.
Once I have my dongles and or breakout PCB's (for the "inconvinient" 1.1mm pinouts and soldering pads below the module), I'll start with the sensor communication, radio transmission and ePaper display. If the range is satisfying with BLE then I also need to decide how I integrate with my controller OpenHAB (a mySensors binding if we get that added, ZigBee, MQTT which a MQTT gateway ...). Would be interested what your plans for integration are (which is also releated to the comment from @scalz)

[scalz]

about indoor range, if you didn't try the TI range estimator excel sheet link, I extracted list of absorption material, if it interests anyone

about using multi protocols in same band, a while ago I modified a graph I found on internet, for comparing wifi less crowded channels VS nrf24/52 channels in MySensors.
Note: zigbee also uses same channels, some implementation can do frequency hopping too, making harder to predict PER packet error rate etc. If I remember Zigbee channel 1 = nrf24/52 channel5. Last zigbee channel being nrf24/52 channel 80.

maybe I'll try to make an article about all this rf stuff (missing time atm).
Still good to know, what possible issues with coexistence of multiple protocols used in same band without good device placement or "time slots" for switching protocols and avoiding "potential collisions". But this would need same synced software for all devices.
I would say, I can be wrong, it's not a great idea to use too many protocols in same band without these precautions, can get messy in air. (not mentioned neigboors playing with different endproducts in same band, antenna detuning, efficiency due to hw designs, ->shifting center freq, bandwitdth etc..).

[NeverDie]

Sadly, at least as of June 2018, none of the smartphones supported the long range capabilities of Bluetooth 5, only just the 2mbps Bluetooth 5 capability. :(

Bluetooth 5 features in smartphones

Bluetooth 5 includes capabilities for faster speed and longer range. It’s fairer to say, however, that developers must choose between speed or range.

Read more: The Bluetooth 5 trade-off

In smartphones, however, you don’t even have that choice. To date none of the smartphones support the Coded PHY that extends the range of Bluetooth 5. Instead you can have the 2mbps speed. For most applications this is likely to be fine. Most consumers are looking for ways to connect to devices that are within a few feet of them. The longer-range features are more useful for lower bandwidth applications such as sensor networks.
https://blog.nordicsemi.com/getconnected/bluetooth-5-in-smartphones

I don't know if that's an android limitation which might improve, or whether the radio chips in the phones are missing the required hardware to do coded 125kbps Bluetooth 5 long range. I can understand that there's a chicken and egg dilemma holding things back, and that right now there's probably not any reason for phone manufacturers to give long range priority in their phones, since at present there's very few, if any, devices for the phones to connect with using Bluetooth 5 long range.

Nonetheless, this post has links to demo code for long-range bluetooth on the Nordic: https://devzone.nordicsemi.com/f/nordic-q-a/38267/long-range/148485#148485 :)

[heinzv]

@neverdie I read an article regarding BLE 5.0, ANdroid and the Samsung Galaxy S8 HW (the used SoC from Qualcom/Snapdragon or from Samsung varying on the model/region).
The article is in German but it says: BLE 5.0 was introduced with Android 8.0 but the S8 HW does only support the 2x data rate (2MBps) but not the 4x range. So it seem that it is a HW limitation similar to the nRF52832 in comparison to the nRF52840. Only the 840 support both, the 832 only the higher data rate. Strange, that this is so bound to the HW and thus so limiting and unflexible.

[NeverDie]

It's worth noting that Texas Instruments has a $29 launchpad which demonstrates its flavor of Bluetooth Long Range: http://www.ti.com/tool/launchxl-cc2640r2
It uses a Cortex M3 rather than an M4.
I think it might be worth looking into to see whether it's any easier to use than SES.

Cypress Semiconductor has its version, with kits starting at $49.
http://www.cypress.com/products/ble-bluetooth

Likewise, silicon labs has its version, but the starter kit is $99: https://www.silabs.com/support/getting-started/bluetooth/bluetooth-low-energy
https://www.silabs.com/products/wireless/learning-center/bluetooth/bluetooth-5?gclid=EAIaIQobChMIodewu8PR3QIVXrXACh2IZwE5EAAYASAAEgI3OfD_BwE

Are there other manufacturers worth noting?

I wish at least one of them had an official video course. That would speed up the learning process. I think Nordic has made the mistake of not making it easier to learn how to develop for their product. It wouldn't be hard for them to do a high quality video tutorial, and yet it appears they've done just the bare minimum. I have some hope that TI may be better in this regard, but I haven't yet looked more closely to say for sure.