Arduino Nicla Sense ME as a MKR Shield

Overview

The form factor of the Nicla Sense allows the board to be used as a MKR shield. In this tutorial, we will walk you through converting the Nicla Sense Board into a shield to extend some of the functionalities of the MKR boards, using the I²C communications, and explain how this communication functions through an example sketch.

Goals.

• How to solder the headers on the Nicla Sense ME
• How to establish an I²C communication between the MKR WiFi 1010 and the Nicla Sense

Required Hardware and Software

• Arduino IDE 1.8.10+ or Arduino Pro IDE 0.0.4+
• MKR WiFi 1010
• Nicla Sense ME
• 1x USB A Cable to Micro USB
• 2x row of Male Headers (1x9 1x8)
• Soldering tool and Stain.
• Libraries to be downloaded from the Library Manager

The following sketches can be found inside the Arduino_BHY2 and Arduino_BHY2Host libraries, available in the Library Manager. You will need to add the changes shown in this tutorial

Instructions

1. The Setup

You will need the latest version of the mbed_portenta core to be able to install the needed drivers for the Nicla Sense ME (minimum v2.5.2). Install the Arduino_BHY2 and Arduino_BHY2Host libraries from the Library Manager.

To convert the Nicla Sense ME into a Shield, you will have to solder 2 rows of headers: one side has 9 pins and the other 8 pins, the long side of the headers needs to be on the battery connectors side.

Once the headers are soldered, you can plug the Nicla on top of the MKR, having the Nicla Sense ME LED and Reset button pointing upwards. Additionally, to further confirm the correct positioning, the white silk outline in the GND pin of the Nicla Sense ME needs to be aligned with the MKR GND pin. Have a look at the video to figure out the correct orientation of the board.

This set-up works with the ESLOV cable as well. Keep in mind female headers or raw cables can be used as well, but make sure the connections of the pinout match with the MKR pinout (3V3, GND, SCL and SDA).

2. Structure of the Communication

The host (MKR WiFi 1010) will communicate through the BHY2Host library with the Nicla Sense ME (both devices communicate over I²C).

3. Host Communication of the MKR WiFi 1010

To make the host communicate with the Nicla Sense ME mounted as a shield, you can modify one of the existing examples. Open the sketch under Examples > Arduino_BHY2Host > Accelerometer and modify the

setup

Add the following parameters to

BHY2Host.begin()

BHY2Host.begin(false, NICLA_AS_SHIELD);

The first parameter defines if the data should be passed through the Serial connection. This allows to control the Nicla Sense ME from a PC when connected through a host board. You can use the

arduino-bhy

Full sketch:

Copy
1#include "Arduino.h"
2#include "Arduino_BHY2Host.h"
3
4SensorXYZ accel(SENSOR_ID_ACC);
5
6void setup()
7{
8  // debug port
9  Serial.begin(115200);
10  while(!Serial);
11
12  BHY2Host.begin(false, NICLA_AS_SHIELD);
13
14  accel.begin();
15}
16
17void loop()
18{
19  static auto printTime = millis();
20  BHY2Host.update();
21
22  if (millis() - printTime >= 1000) {
23    printTime = millis();
24    Serial.println(String("Acceleration values: ") + accel.toString());
25  }
26}

4. Program the Nicla Sense ME

Program the Nicla Sense ME with the App.ino sketch from the BHY2 library. You can find it under Examples > Arduino_BHY2 > App . Modify it as follows:

Navigate to the

setup

BHY2.begin()

Copy
1BHY2.begin(NICLA_I2C, NICLA_AS_SHIELD);

You may use

NICLA_I2C

NICLA_BLE

NICLA_BLE_AND_I2C

NICLA_VIA_ESLOV

NICLA_AS_SHIELD

These settings will internally adjust the communication parameters, so it can communicate through the headers.

We suggest to unplug the Nicla Sense ME from the host Arduino board while connecting the USB to the computer.

Full sketch:

Copy
1#include "Arduino.h"
2#include "Arduino_BHY2.h"
3
4// Set DEBUG to true in order to enable debug print
5#define DEBUG false
6
7void setup(){
8#if DEBUG
9  Serial.begin(115200);
10  BHY2.debug(Serial);
11#endif
12
13  BHY2.begin(NICLA_I2C, NICLA_AS_SHIELD);
14}
15
16void loop(){
17  // Update and then sleep
18  BHY2.update(100);
19}

Conclusion

This tutorial shows how easy is to access the Nicla Sense ME sensors data and pins if it is plugged as a shield.

The BHY2 Library encapsulates the I2C communication and therefore reduces the complexity of your sketch.

Troubleshooting

Make sure you have installed the latest version of both libraries Arduino_BHY2 and Arduino_BHY2Host.

If you do not see any output on the Serial Monitor, make sure you have set the correct baud rate. In this example sketch we use 115200.

Make sure the pins are soldered on the correct side and the Nicla Sense ME is mounted with the correct orientation on the host board.

Next Steps

Leverage the Arduino Cloud dashboard to select which sensor you want to use and initialize, so you can remotely control your application.