GUIDE - NRF5 / NRF51 / NRF52 for beginners

[monte]

Mentioned hardware bugs are easily omitted by using custom sleep function.

[Puneit Thukral]

@monte Could you please share the custom sleep function?

[monte]

@Puneit-Thukral you can start looking from here https://forum.mysensors.org/post/92044

[electrik]

Is it possible to use such a ready made device, and reprogram it with a mysensors sketch?

https://a.aliexpress.com/_v4kOXD

[monte]

@electrik yes. You will need an SWD programmer, J-link, ST-link or black magic probe will do. But the thing, you've linked isn't NRF5 device. So if you are asking about exactly that device, then answer is no. Only Nordic bluetooth devices are supported by mysensors. The one you've linked uses TI chip.

[electrik]

@monte Thanks. I didn't notice it was not a Nordic one. So if I take such module, I just have to figure out the pins to program and it can be re-used.
Did you or someone else ever tried this?

https://nl.aliexpress.com/item/4000389437486.html?spm=a2g0o.productlist.0.0.454562f4dPgTnm&algo_pvid=453cb8be-1c2a-43ea-a56c-61bbbf3a4822&algo_expid=453cb8be-1c2a-43ea-a56c-61bbbf3a4822-26&btsid=2100bdf116156431118194203efa5d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

[nagelc]

Hi @electrik

You can program these ibeacons to work with MySensors.
I reprogrammed one by soldering some wires to a jlink adapter. Not elegant, but it worked.
Some type of push pin setup would be good if you are going to actually use these modules.

The version I got had only a button on the board, and no way to easily add any other sensors, so they weren't very useful. It would be interesting to try the ones with the temperature and acceleromator.

[abelson]

I am using a generic nRF52 dev board with the Arduino nRF52 core. I am trying to get a sample BLE service to display, but it cannot find it on my BLE scanner. After I couldn't get that to work, I decided to make the code even simpler. Since the dev board that I am using has a serial USB out I thought I would just check if I could get a "Hello World!" to the serial monitor... After flashing the soft device, I still couldn't get any output on my serial monitor.

Open On-Chip Debugger 0.10.0-dev-00254-g696fc0a (2016-04-10-10:13)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
debug_level: 0
0x4000
adapter speed: 10000 kHz
nrf52.cpu: target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x61000000 pc: 0x0001b08e msp: 0x20001188
nrf52.cpu: target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x01000000 pc: 0xfffffffe msp: 0xfffffffc
** Programming Started **
auto erase enabled
nrf52.cpu: target state: halted
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000001e msp: 0xfffffffc
wrote 114688 bytes from file C:\Users\Admin\Documents\ArduinoData\packages\sandeepmistry\hardware\nRF5\0.7.0/cores/nRF5/SDK/components/softdevice/s132/hex/s132_nrf52_2.0.1_softdevice.hex in 2.559271s (43.762 KiB/s)
** Programming Finished **
** Verify Started **
nrf52.cpu: target state: halted
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
nrf52.cpu: target state: halted
target halted due to breakpoint, current mode: Thread 
xPSR: 0x61000000 pc: 0x2000002e msp: 0xfffffffc
verified 110636 bytes in 0.372659s (289.924 KiB/s)
** Verified OK **
** Resetting Target **
shutdown command invoked

I am using OpenOCD and an ST-Link v2 to upload my code and it looks like it is uploading successfully. Here is the output when I try to flash the S132 soft device:

void setup() {
  Serial.begin(9600);
  Serial.println("Starting...");

}

void loop() {
  Serial.println("Hello World!");
  delay(1000);

}

I also tried running this code with the MySensors library:

#define MY_RADIO_NRF5_ESB
#include <MySensors.h>

void setup() {
  Serial.begin(9600);
  Serial.println("Starting");
}

void loop() {
  Serial.println("Hello World!");
  delay(3000);
}

And got this error:

In file included from C:\Users\Admin\Documents\ArduinoData\packages\sandeepmistry\hardware\nRF5\0.7.0\cores\nRF5/Arduino.h:5:0,
                 from sketch\MyBoardNRF5.ino.cpp:1:
c:\users\admin\documents\arduinodata\packages\sandeepmistry\tools\gcc-arm-none-eabi\5_2-2015q4\lib\gcc\arm-none-eabi\5.2.1\include\stdint.h:9:26: fatal error: stdint.h: No such file or directory
compilation terminated.
exit status 1
Error compiling for board MyBoardNRF5 nRF52832.
Error while flashing SoftDevice.
java.io.FileNotFoundException: C:\Users\Admin\Documents\ArduinoData\packages\MySensors\hardware\nRF5\0.3.0\softdevices.txt (The system cannot find the file specified)

[monte]

@abelson first you have to flash SD and then chose softdevice in board options and flash your sketch.
It seems that you are lacking softdevice binary. It seems that your version of sandeepmistry's NRF5 core is pretty outdated, you have 0.3 version when surrent version is 0.7. No wonder that links to softdevice binaries are broken in softdevices.txt. Try updating core to the latest version and/or downloading softevice binary from nordic's site yourself.

[abelson]

@monte that makes sense. Do you know what options I have to do to flash the sketch after I flash the soft device? If I get the above output that I posted, does that mean that the soft device flashed successfully?

[monte]

@abelson no. You need to have softdevice binary on your PC to flash it to NRF board. Please, read my answer above and try to do, what I suggested.

You need to choose softdevice option if it has been flashed to the board.

[electrik]

This post is deleted!

[electrik]

@BearWithBeard
Great explanation, thanks!
On my windows 10 installation I had to run Zadig to make the programming from platformIO work.

[electrik]

@BearWithBeard
What did you do to get the serial pins of the Ebyte development board configured correctly, when using the generic board variant in platformIO? I've copied MyBoardNRF5.cpp but this is not used it seems.
Also redefining the definitions from variant.h

#define PIN_SERIAL_TX (11)
#define PIN_SERIAL_RX (12)

doesn't give serial output.

[BearWithBeard]

@electrik Yeah, I ran into that issue, too. Not sure if that's the proper way to solve it, but I add a custom board directory to the build flags in platformio.ini ...

build_flags = 
	-I $PROJECT_DIR/boards/generic

... and copied the board variant files from .platformio/packages/framework-arduinonordicnrf5/variants/Generic/ to boards/generic/ in my project folder. Changes made in here aren't ignored or overwritten by global PIO definitions.

[electrik]

@BearWithBeard Thanks that did it.
Could it be the TX and RX are switched on the BMP in your post?

[BearWithBeard]

@electrik Good to hear. And yes, I think you are right. I'll swap them and change the naming to RXI and TXO to clarify the directionality. Thanks for the hint!

[Ivanli]

Great post, thanks a lot for sharing.

[nagelc]

With respect to initial erase of NRF52, I have been using @BearWithBeard Black Magic Probe instructions successfully for years. But, my latest set of Minew boards doesn't respond.
I found that there is a new lock procedure from Nordic:

https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/working-with-the-nrf52-series-improved-approtect

I have tried upgrading my gdb and also J-Link EDU and nrfjprog tool chains and have not successfully connected to the new boards yet.

Has anyone had success with unlocking one of these new boards?

[NeverDie]

@nagelc Sorry I don't have an informed answer, but thanks for posting and making us aware of your experience with the minew's! Haven't heard from you in a while. Have you tried upgrading the firmware on the J-link that's part of a DK? I can't say that I have, but the firmware upgradeability was one of the alleged selling features of a DK's J-Link. That potential upgradeability didn't ever seem to matter, but maybe now it does.

As for me, after a long break I'm back to have a run at getting the nRF52805 to work. So far I've got bare metal blinking and bare metal UART working. I'm opting for bare metal code because it's unclear how well anything else will work with the nRF52805, which doesn't seem all that well supported. Soon to get some basic bare metal proprietary radio working, I hope.... If successful, I'll post it to github to memorialize it. There are surprisingly few examples of bare metal code out there, even though that's all the datasheet itself talks about. I guess I can understand why, because I've found some surprising ambiguities in the datasheet. For instance, who would have thought that PSELTXD would refer to an actual pin number and not to a bitmask? From the datasheet I thought for sure it would be a bitmask (like nearly everything else in the datasheet), but no, it's the actual pin number. I mean, why does the datasheet show literally every bit of a 32 bit word is relevant for specifying the pin number? On a different issue, bare metal UART doesn't work quite right without some artificial delays, even if driven by interrupt events, apparently because the actual generated baudrates aren't exactly right (something the datasheet admits). So, there's some finessing involved that you don't see when you're only working from abstracted libraries.

Regardless, the architecture itself remains pretty cool, and I enjoy it a lot!