Everything nRF52840

[monte]

@neverdie why won't you use Nordic's native SDK with Eclipse? I found some tutorials how to set it up, so I guess it's an option.

[heinzv]

@neverdie thanks for the info, I appreciate your effort and investigations. I'll use my gateway and the sensor nodes at least in 1,5m height from the ground.
Today I got my nrF52832 and also the nRF52840. The E73..C modules are tiny (around 11x16mm). I can't use it without a breakout board. CDBYTE promised me to send me at least reference PCB design which I can then order from any PCB company.

The Skylab moduls are promising, but I see some deficiencies: No pinout, less pins (don't know what was skiped), no 32kHz low power quart for sleep timer ... I have ordered some other modules ... lets see, so far I can't test a lot without the carrier PCB's.
Then I join you with testing (range/transmisson test, sensor readout, battery measurement, ePaper ...)

[NeverDie]

I seem to be getting noticeably better coverage when receiving with a BT840F than with an nRF52840-DK. That's a bit surprising, as the ground plane is smaller. The are several possible explanations, but I'm guessing the metal can around the radio, which the BT840F has but the nRF52840-DK lacks, probably helps reduce the effective noise floor and thereby improve the S/N ratio. So, if you're picking a module, you may want to pick a module which has that. :) Most of them don't, but there are a few that do.

[NeverDie]

It turns out mbed does support the p1 pins. It just uses a different notation. Instead of P1_00, it's P1_0. Here's a link to all of the pin names: https://github.com/ARMmbed/mbed-os/blob/master/targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/TARGET_MCU_NRF52840/TARGET_NRF52840_DK/PinNames.h

So, because of ease of use and that I'm already started with it, I'm going to stick with mbed a bit longer. I have run across one inconvenient bug relating to send serial communications, but I've reported it, and I've devised a workaround to it until it gets fixed.

Meanwhile, with all the above tweaks, I'm getting pretty good home coverage with just a single gateway mounted centrally on the second floor. It's not yet at LoRa's near perfect transmission/reception for a every conceivable nook and cranny in a home environment, but I suspect it may approach that once the amplified modules becomes available. And that's all transmitting at 1mbps, without the benefit of BLE Long Range which it is capable of doing.

[Nca78]

And what about Segger Embedded Studio ? It's now free to use with Nordic SDK for NRF5 MCUs
https://www.segger.com/news/segger-embedded-studio-ide-now-free-for-nordic-sdk-users/

[NeverDie]

I resurrected @d00616 's code for reading the supply voltage to the nRF52, and it seems to work reasonably accurately on the nRF52840-DONGLE. Here it is again to spare people from searching for it:

uint16_t hwCPUVoltage()
{
  // VDD is prescaled 1/3 and compared with the internal 1.2V reference

  int32_t sample;
  NRF_SAADC->ENABLE = SAADC_ENABLE_ENABLE_Enabled << SAADC_ENABLE_ENABLE_Pos;
  NRF_SAADC->RESOLUTION = SAADC_RESOLUTION_VAL_8bit << SAADC_RESOLUTION_VAL_Pos;
  NRF_SAADC->CH[0].PSELP = SAADC_CH_PSELP_PSELP_VDD << SAADC_CH_PSELP_PSELP_Pos;
  NRF_SAADC->CH[0].CONFIG = (SAADC_CH_CONFIG_BURST_Disabled << SAADC_CH_CONFIG_BURST_Pos) |
                            (SAADC_CH_CONFIG_MODE_SE << SAADC_CH_CONFIG_MODE_Pos) |
                            (SAADC_CH_CONFIG_TACQ_3us << SAADC_CH_CONFIG_TACQ_Pos) |
                            (SAADC_CH_CONFIG_REFSEL_Internal << SAADC_CH_CONFIG_REFSEL_Pos) |
                            (SAADC_CH_CONFIG_GAIN_Gain1_6 << SAADC_CH_CONFIG_GAIN_Pos) |
                            (SAADC_CH_CONFIG_RESN_Bypass << SAADC_CH_CONFIG_RESN_Pos) |
                            (SAADC_CH_CONFIG_RESP_Bypass << SAADC_CH_CONFIG_RESP_Pos);
  NRF_SAADC->OVERSAMPLE = SAADC_OVERSAMPLE_OVERSAMPLE_Bypass << SAADC_OVERSAMPLE_OVERSAMPLE_Pos;
  NRF_SAADC->SAMPLERATE = SAADC_SAMPLERATE_MODE_Task << SAADC_SAMPLERATE_MODE_Pos;
  NRF_SAADC->RESULT.MAXCNT = 1;
  NRF_SAADC->RESULT.PTR = (uint32_t)&sample;

  NRF_SAADC->EVENTS_STARTED = 0;
  NRF_SAADC->TASKS_START = 1;
  while (!NRF_SAADC->EVENTS_STARTED);
  NRF_SAADC->EVENTS_STARTED = 0;

  NRF_SAADC->EVENTS_END = 0;
  NRF_SAADC->TASKS_SAMPLE = 1;
  while (!NRF_SAADC->EVENTS_END);
  NRF_SAADC->EVENTS_END = 0;

  NRF_SAADC->EVENTS_STOPPED = 0;
  NRF_SAADC->TASKS_STOP = 1;
  while (!NRF_SAADC->EVENTS_STOPPED);
  NRF_SAADC->EVENTS_STOPPED = 1;

  NRF_SAADC->ENABLE = (SAADC_ENABLE_ENABLE_Disabled << SAADC_ENABLE_ENABLE_Pos);

  return (sample*3600)/255;
}

With that as a voltage reference point, I plan to next try reading and wireless reporting the voltage on a solar panel, the one charging the supercap that will be powering the dongle.

It's nice that the previous work done on the nRF52832 is easily and quickly ported to the nRF52840. :)

[NeverDie]

I found a driver for doing 802.15.4 on the nRF52840 that looks rather interesting: https://github.com/NordicSemiconductor/nRF-IEEE-802.15.4-radio-driver
The sample application its Wiki makes it look rather easy to use:
https://github.com/NordicSemiconductor/nRF-IEEE-802.15.4-radio-driver/wiki/Sample-application

[NeverDie]

@nca78 said in Everything nRF52840:

And what about Segger Embedded Studio ? It's now free to use with Nordic SDK for NRF5 MCUs
https://www.segger.com/news/segger-embedded-studio-ide-now-free-for-nordic-sdk-users/

Looks quite promising, and probably easier to setup than eclipse. Actually seems quite sophisticated with tight debugger integration.

I tried to get started with eclipse, and I immediately got lost. I just couldn't find a good tutorial for its C++ IDE. Segger looks as though it may be simpler.

In order to be able to run the 802.15.4 demo code, which I refer to above, I need to be able to use an IDE that can utilize the Nordic SDK. I'm not sure that mbed can do that. So, unless someone knows of anything simpler, maybe segger embedded studio is it.

[NeverDie]

I have Segger Embedded Studio (SES) up and running now. I built and ran the Nordic SDK's "hello world" over serial example. It works. Following this video made it easy:
https://www.youtube.com/watch?v=YZouRE_Ol8g&index=2&t=0s&list=PLx_tBuQ_KSqGHmzdEL2GWEOeix-S5rgTV

It's clear from this that all the Nordic SDK examples directly support SES, because there are preconfigured files within the Nordic SDK for building each example on Segger Embedded Studio. :) I don't see the same for mbed. :(

Also, as an aside, it's worth noting that the SDK's after 12.3 no longer support the nRF51. The current nordic SDK is version 15.2. Make of that what you will.

[NeverDie]

I have the wireless uart over 802.15.4 example working. The description on how to set it up and run it is here: http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v13.0.0%2Fnrf_log.html&cp=4_0_0_3_20

I'll try modifying the github example though to get a better idea as to what kind range improvement is achievable with 802.15.4 at the slower 250kbps.

I'm not sure if this type of info is of interest to others, though, so for now I'll put a pause on further posting.

[monte]

@neverdie I've read about this standard after reading nrf52 page on nordic's site. Please keep posting if it is not difficult for you. I think some time in the future many of current members of mysensors community will look at nrf51/52 MCU's as a replacement and further development of the platform. Seeing someone like you digging deep into the cause will encourage others.

[scalz]

@monte I don't know what to think about this, but just in case, to avoid confusion for newcomers, you can't really use MySensors AND 802.15.4 stacks. it would be redundant. these are two different projects with same goals: providing a RF stack with their own logic (state machine). I mean it's a choice to make : using MySensors or a standard like 15.4 (zigbee etc)

[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