今回の記事ではM5Stack core2とW5500 Ethernet LANモジュールを使ってMQTT BrokerにMessageをPublishしようと考えています。

以下のLinkやAmazonやスイッチサイエンスなどでもモジュール購入可能です。

https://shop.m5stack.com/products/lan-module?variant=16804778803290

Note

注意するのはCore2やCore2-for-awsは使用するとき、Power Modeを使用し、外部24vで供給してください。(そうしないとモジュール正常動作しないときがあります。)

このようなDC adapterがAmazonなどで簡単に購入できます。

Example to power mode

こちらはM5Core2をPower Modeで立ち上げるのSample Codeです。

//mbus_mode_t:
//kMBusModeOutput: Use USB or battery power
//kMBusModeInput: Use external power supply 5V, or DC interface

M5.begin(true, true, true, false, kMBusModeInput);

//Initialize Serial according to the actual connected pins
Serial2.begin(115200, SERIAL_8N1, 13, 14);

Configuration

Here is the configuration in this tutorial. I will use M5Stack W5500 LAN Module to connect with Raspberry, and publish the message by using MQTT.

最初にも書いた通り、今回の記事ではM5Core2とW5500 Ethernet LANモジュールを接続し、Raspberry-pi3にあるMqtt BrokerにMessageをPublishします。

Reference Link

MQTT#using Python Library as a Subscriber and Publisher

MQTT#Connection is refuesd solution

MQTT#Brokerのセットアップ

Code

#include <M5Core2.h>
#include <SPI.h>
#include <Ethernet2.h>
#include <PubSubClient.h>

#define SCK 18
#define MISO 19
#define MOSI 23
#define CS 26

byte mac[] = { 0x90, 0xA2, 0xDA, 0x0F, 0x08, 0xE1 };
IPAddress Local(192, 168, 1, 211);
EthernetClient ethClient;
PubSubClient mqttClient(ethClient);

//MQTT Broker
const char *ENDPOINT=”192.168.001.050″;
const int PORT=1883;
char *MYID=”M5Stack”;
char *PUBLISHTOPIC=”M5Stack/pub”;
char *SUBTOPIC=”RoboDK/Station/s1/#”;

void setup(){

//If LAN Modules is used,Please use this operation mode
M5.begin(true, true, true, false, kMBusModeInput);
Serial2.begin(115200, SERIAL_8N1, 13, 14);

// START
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setCursor(10, 10);
M5.Lcd.setTextColor(WHITE);
M5.Lcd.setTextSize(3);
M5.Lcd.printf(“Inited..\n”);
M5.Lcd.printf(“IP:192.168.1.211\n”);
M5.Lcd.printf(“Mac:90-A2-DA-x0F-08-E1\n”);

mqttClient.setServer(ENDPOINT, PORT);
SPI.begin(18, 19, 23, -1);
Ethernet.init(26);
Ethernet.begin(mac, Local);

connectMQTT();
}

void mqttLoop() {
if (!mqttClient.connected()) {
connectMQTT();
}
mqttClient.loop();

}

void connectMQTT() {
while (!mqttClient.connected()) {
Serial.print(“Connection Loop..”);
if (mqttClient.connect(MYID)) {
Serial.println(“Connected.”);
int qos = 0;
mqttClient.subscribe(SUBTOPIC, qos);
Serial.println(“Subscribed.”);
} else {
Serial.print(“Failed. Error state=”);
Serial.print(mqttClient.state());

// Wait 5 seconds before retrying
delay(1000);
}
}
}

long messageSentAt = 0;
int count = 0;
char pubMessage[128];
int led,red,green,blue;
int status=0;
void loop() {
mqttLoop();
M5.update();
long now = millis();
if (now – messageSentAt > 1000) {
if (status ==0){
M5.Lcd.fillScreen(BLACK);
M5.Lcd.fillCircle(80, 120, 30, GREEN);
M5.Lcd.fillCircle(160, 120, 30, YELLOW);
M5.Lcd.fillCircle(240, 120, 30, RED);
status=1;
}else{
M5.Lcd.fillScreen(BLACK);
M5.Lcd.drawCircle(80, 120, 30, GREEN);
M5.Lcd.drawCircle(160, 120, 30, YELLOW);
M5.Lcd.drawCircle(240, 120, 30, RED);
status=0;
}
messageSentAt = now;
sprintf(pubMessage, “{\”count\”: %d}”, count++);
Serial.print(“Publishing message to topic “);
Serial.println(PUBLISHTOPIC);
Serial.println(pubMessage);
mqttClient.publish(PUBLISHTOPIC, pubMessage);
Serial.println(“Published.”);
}
}

Result

Brokerと接続に成功したらMessageが自動的にPublishされます。

Publishing message to topic M5Stack/pub
{“count”: 9}
Published.
Publishing message to topic M5Stack/pub
{“count”: 10}
Published.
Publishing message to topic M5Stack/pub
{“count”: 11}
Published.
Publishing message to topic M5Stack/pub
{“count”: 12}
Published.
Publishing message to topic M5Stack/pub
{“count”: 13}
Published.
Publishing message to topic M5Stack/pub
{“count”: 14}
Published.
Publishing message to topic M5Stack/pub
{“count”: 15}
Published.