Wisnode shield on Arduino Mega code

[Oldfield (John Allen)]

I have 4x Wisnodes. Purchased them to set up 4 nodes with sensor data as payloads. I was attracted to the Wisnode because I hold RAK products in very high regard, and secondly the Wisnode can be viewed as a shield for Arduino Mega.

I have a similar node based on a Dragino LoRa module/shield and Arduino Uno which works perfectly. I just put code into the Uno and the node took off.

Similarly, I expected to mount the Wisnode shield onto the Arduino Mega, download code from Github, and the world wld be sweet, but no.

The only tutorial I have found is -

Https://create.arduino.cc/project hub/naresh-Krish/getting-started-with-the-rak81-LoRa-node-67f157

and you don’t appear to mount the shield on the mega, and you have to make modifications to the module with side cutters and soldering iron.

Can anyone please point me in the direction of a tutorial/project(s) that establishes the Wisnode as a stand alone node and/or a Wisnode mounted on a mega with appropriate code to drive it as a node, or better, a sensor values Payload node.

Many thanks.

[nmcc (Nick McCloud)]

On the product page there is a link to the documentation:

RAK811 LPWAN Evaluation Board

https://doc.rakwireless.com/rak811-lora-evaluation-board
https://downloads.rakwireless.com/LoRa/WisNode/

The Arduino specific instructions are here:

https://doc.rakwireless.com/rak811-lora-evaluation-board/interfacing-your-rak811-lora-evaluation-board-with-arduino-boa

which yields:

RAKWireless/WisNode-Arduino-Library

[Nicholas]

Dear John
Please refer this link：

GitHub - RAKWireless/WisNode-Arduino-Library: This repo is used for Arduino...

You mentioned earlier：

I have a similar node based on a Dragino LoRa module/shield and Arduino Uno which works perfectly. I just put code into the Uno and the node took off.

It will lose the unique functionality of a module, only using WisNode as an RF module, controlled by Arduino. This will not be necessary for the MCU in Wisnode.

Best regards！

[nmcc (Nick McCloud)]

Important notes:

In the library examples, there is a line that sets the working mode to LoRaWAN:

if(!RAKLoRa.rk_setWorkingMode(0)) //set WisNode work_mode to LoRaWAN.

This requires a reset / reboot / power-cycle of the module to take effect and I find the RAK811 will actually stop until this has happened.

In addition, communicating with an Arduino at the default speed of 115200 is problematic as the Arduino clock can’t actually accurately run 115200 baud rate, so it’s best to slow it down - 9600 is rock solid and as the data exchange is minimal, the slower rate isn’t an issue.

You can use the Serial Tool to set the working mode and change the baud rate. This only needs to be done once. Or write a sketch for first run on the board to change things over.

I’ve found the modules to work splendidly, any questions, post here and tag me, I’m on most days.

[rlpdavid (Ralph)]

Hi Nick,

I am having error with this line if(!RAKLoRa.rk_setWorkingMode(0)) //set WisNode work_mode to LoRaWAN.

The only difference is that I’m using P2P examples, receiver and sender codes but to no avail. I updated the baud rates in serial tool to 9600. pins triple checked, updated firmware but I cant seem to make it work.

I have a pair of RAK811 433mhz v1.3 using arduino uno on both EVBs.

Can you please help.

Thanks!
R

[nmcc (Nick McCloud)]

@rlpdavid

I am having error with this line if(!RAKLoRa.rk_setWorkingMode(0)) //set WisNode work_mode to LoRaWAN.

You’ll need to set it to 1 for P2P and as above:

@nmcc

This requires a reset / reboot / power-cycle of the module to take effect and I find the RAK811 will actually stop until this has happened.

I think you’ll find it’s done it - but the library expects a response which it doesn’t get due to above. Just set it the once at the same time as setting the baud rate.

[nmcc (Nick McCloud)]

@rlpdavid

My issue that I would like to ask you is that I’m trying to pair my RAK811 shield to arduino uno and cant seem to make them work. Followed all the instructions I can find online (including yours) but still having the same error of SET WORK_MODE FAILED. RAK811 and the UNO can’t seem to communicate.

I saw one underlying instruction by removing the resistors r8,r11,r12,r13 to make it work with an UNO here that states that I remove them to make it work with an UNO? 3.3v of the RAK vs 5v or the uno.

Will removing the resistors fix the miscommunication between the two?

From a direct message, copied here so that all can benefit.

@rlpdavid, if you have a v1.2 board, you will need to remove at the very least, R12 & 13 as these are connected to the Arduino’s serial port, the one you use to program it with, so this will solve the lack of communication.

R8 appears to reset the shield if the Arduino is reset and R11 allows you to reset the shield via D8 from your code (a good thing to have).

There is level shifting on the shield to handle the different voltages, so you are all good in that dept.

[Oldfield (John Allen)]

NMCC and Nicholas. Thank you for your replies. I have been through all the references and have learnt heaps. However, I’m still a bit stuck. Leaving aside mounting the Wisnode on a Mega, I have managed to get the standalone Wisnode to join my gateaway/TTN The join request was acknowledged/established the moment I put a payload into the node;

at+send=lora:1:12345678

So my next question is how do I put a “real” payload into the node?

I have this piece of code from the RAKWireless/WisNode-Arduino-Library

/********************************************************

• This demo is only supported after RUI firmware version 3.0.0.13.X on RAK811
• Master Board Uart Receive buffer size at least 128 bytes.
  ********************************************************/

#include “RAK811.h”
#include “SoftwareSerial.h”
#define WORK_MODE LoRaWAN // LoRaWAN or LoRaP2P
#define JOIN_MODE OTAA // OTAA or ABP
#if JOIN_MODE == OTAA
String DevEui = “8680000000000001”;
String AppEui = “70B3D57ED00285A7”;
String AppKey = “DDDFB1023885FBFF74D3A55202EDF2B1”;
#else JOIN_MODE == ABP
String NwkSKey = “69AF20AEA26C01B243945A28C9172B42”;
String AppSKey = “841986913ACD00BBC2BE2479D70F3228”;
String DevAddr = “260125D7”;
#endif
#define TXpin 11 // Set the virtual serial port pins
#define RXpin 10
#define DebugSerial Serial
SoftwareSerial ATSerial(RXpin,TXpin); // Declare a virtual serial port
char buffer[]= “72616B776972656C657373”;

bool InitLoRaWAN(void);
RAK811 RAKLoRa(ATSerial,DebugSerial);

void setup() {
DebugSerial.begin(115200);
while(DebugSerial.available())
{
DebugSerial.read();
}

ATSerial.begin(9600); //set ATSerial baudrate:This baud rate has to be consistent with the baud rate of the WisNode device.
while(ATSerial.available())
{
ATSerial.read();
}

if(!RAKLoRa.rk_setWorkingMode(0)) //set WisNode work_mode to LoRaWAN.
{
DebugSerial.println(F(“set work_mode failed, please reset module.”));
while(1);
}

RAKLoRa.rk_getVersion(); //get RAK811 firmware version
DebugSerial.println(RAKLoRa.rk_recvData()); //print version number

DebugSerial.println(F(“Start init RAK811 parameters…”));

if (!InitLoRaWAN()) //init LoRaWAN
{
DebugSerial.println(F(“Init error,please reset module.”));
while(1);
}

DebugSerial.println(F(“Start to join LoRaWAN…”));
while(!RAKLoRa.rk_joinLoRaNetwork(60)) //Joining LoRaNetwork timeout 60s
{
DebugSerial.println();
DebugSerial.println(F(“Rejoin again after 5s…”));
delay(5000);
}
DebugSerial.println(F(“Join LoRaWAN success”));

if(!RAKLoRa.rk_isConfirm(0)) //set LoRa data send package type:0->unconfirm, 1->confirm
{
DebugSerial.println(F(“LoRa data send package set error,please reset module.”));
while(1);
}
}

bool InitLoRaWAN(void)
{
if(RAKLoRa.rk_setJoinMode(JOIN_MODE)) //set join_mode:OTAA
{
if(RAKLoRa.rk_setRegion(5)) //set region EU868
{
if (RAKLoRa.rk_initOTAA(DevEui, AppEui, AppKey))
{
DebugSerial.println(F(“RAK811 init OK!”));
return true;
}
}
}
return false;
}

void loop() {
DebugSerial.println(F(“Start send data…”));
if (RAKLoRa.rk_sendData(1, buffer))
{
for (unsigned long start = millis(); millis() - start < 90000L;)
{
String ret = RAKLoRa.rk_recvData();
if(ret != NULL)
{
DebugSerial.println(ret);
}
if((ret.indexOf(“OK”)>0)||(ret.indexOf(“ERROR”)>0))
{
DebugSerial.println(F(“Go to Sleep.”));
RAKLoRa.rk_sleep(1); //Set RAK811 enter sleep mode
delay(10000); //delay 10s
RAKLoRa.rk_sleep(0); //Wakeup RAK811 from sleep mode
break;
}
}
}
}

---

The payload sits here -

char buffer[]= “72616B776972656C657373”;

(1) How do I, for instance, get sensor data into here?

(2) And while I’m at it, how do I get that code above into my Wisnode?

I’ll bet that’s pretty simple for someone, but right now, not for me.

Many thanks. Regards.

[nmcc (Nick McCloud)]

The WisNode is a self-contained module, as you’ve discovered.

The code above goes on to the Arduino Mega and you send the commands to the WisNode from your code to get it to send your payload. So you will need to:

If not already, get the Arduino IDE installed

• Read about Arduino programming 101
• Put the starter code above on your Mega and test
• Write the code to read your sensors - what are they?
• Write the code to put the data from the sensors in to the buffer.

If you get started with the first three bullet points and tell us what sensors you have, we’ll be here when it’s time to code them.

[Oldfield (John Allen)]

Hi Nick. I have a DHT22 module connected to a Dragino LoRa shield mounted on a Arduino Mega. I wrote the code. Its set up as a node. I get the temp and the humidity off the TTN. Works perfectly. It works exactly as you describe above. I have a total of 4 nodes installed and working.

I have a really major project going here that I designed and wrote the code for that manages water delivery across the farm. It prioritises the use of water across humans, animals, and vegetation. It get the time of GPS to determine summer time/winter time, and accordingly restricts irrigation. It detects the presence if rain and inhibits irrigation.

I have done Arduino 101 and I can write in C (among other programming languages). I have Arduino IDE installed.

Cld you please confirm one thing. The Wisnode does not get mounted on the Mega. It sits on its own with jumper connection to Rx/Tx pins … plus VCC?

If do mount it on the Mega, I have to break the 4 resistors 12, 13, 17, 19.

Thank you for your help. Regards

[Oldfield (John Allen)]

I think part of my problem is use of the word “stand alone”. If Wisnode was stand alone, I’d have thought the sensor was connected directly to the Wisnode, and the code installed on the Wisnode.

I think if I regard it as a shield, then I don’t have a problem … except for the 4 resistors that have to be removed.

[nmcc (Nick McCloud)]

The WisNode does not need anything else for you to connect to LoRaWAN - that’s my meaning of standalone. But it’s tricky to connect sensors & program for but the facility is there if you want to get in to RUI.

So if you follow the instructions for which ever version of WisNode you have - I think v3 is jumpers and the others are resistors that need removing - you can then treat it as a shield, plug it on top of your Mega and use the library linked to above which allows you to code the same commands that you typed in directly.

Or yeah, link over to Rx & Tx plus GROUND and leave it next to your Mega but not plugged in. I use SoftSerial at 9600 so I’ve still got the main USB serial port for debug and programming.

[Oldfield (John Allen)]

Great. Thanks. To labour the point, if I purchase a v1.3, I don’t have to remove the resistors, and I can mount the Wisnode on the mega and then follow the tram lines?

[nmcc (Nick McCloud)]

I know the answer, but this is definitely in the flogging a dead horse territory and we are in a ‘teach a man to fish’ mood.

So, what does the document specifically for the v1.3 say - or more importantly, what does it show on the picture?

PS, yes, it’s a bit of an egg hunt as not all the docs are in the same place, but places do absolutely scream V1.3 …

[Oldfield (John Allen)]

Hi Nick. I’m not sure what your first para means. Most of my professional career was in Software Engineering. I was part of a team ion the UK who developed the world’s first electronic telephone exchange for the British Post Office. Pretty sure I know how to fish. I am keen to learn how to use AT commands, and also to use RUI. I think my biggest challenge is the lack of absolutely clear documentation.

I tried to update the firmware on my Wisnode/RAK811 board. It took a whole day. Had to reload the boot-loader as well. Now AT commands dont work. However, I will persevere and I will get it going.

Hate to say, I have looked at every v1.3 doc I can find, but as yet haven’t found a picture that you refer to.

Rome wasn’t built in a day, but it was built.

Thank you for your assistance to date. Undoubtedly, you have helped me make progress.

Just BTW, if I ordered a new Wisnode … which now appears to be called Wisduo, will I automatically get a v1.3?

Regards.

[Nicholas]

Dear John,
The V1.3 mentioned by nick is the corresponding hardware model of wisnode. For different reasons, the latest hardware has been upgraded to V1.3, and the arduino connection method corresponding to it has also changed. You must refer to the documentation of the corresponding model. Connect to ensure the normal operation of the program.

[Oldfield (John Allen)]

Thank you for your reply. Much appreciated.

I think I now have a good understanding of the issues surround interfacing a Mega to a Wisnode RAK811. So before I ventured any further, I thought I’d upgrade the firmware on the Wisnode, I followed the TTN instruction to the letter.

That took some doing. I ended up reloading the boot loader as well as the firmware (to V3.0.0.14T3). However, when I go to RAK Serial Port Tool, i can out in any at command but I don’t get any response as per the screen shot below.

I have 4x Wisnodes v1.2. The first one tried this on has had R11, R12 etc decimated for mounting on the Mega. I got the response as per the screen shot.

So I tried another virgin Wisnode. I got the same screen shot. No response to the AT commands.

I reverted to the third virgin Wisnode just to be sure and it works like a charm as a standalone node.

Can anyone help me with this please

Regards.

[Nicholas]

Dear，
Can you show your Wisnode connection diagram? I want to find some problems through it. Before this, you must ensure that the firmware is programmed normally.

[Oldfield (John Allen)]

Very happy to do that. I’ll get onto it. Thanks.

[Nicholas]

Dear,

Have a question. You must burn firmware on github If you want to using RAK wisnode and Arduino.