目標

RTK基地局が調子悪い時に切り替えたい

UI作ればいい

わかってるよそりゃ・・。けど大変。

力技で解決する

LovyanLauncher
https://raspberrypi.mongonta.com/howto-start-m5stack-m5burner-lovyanlauncher/
SDカードに基地局の設定を変えたbinファイルを置き、LovyanLancherで書き換える。

ソース

M5Stackのセットアップ

ntrip client for arduino

zipでダウンロードして、arduinoに入れてください。
https://github.com/GLAY-AK2/NTRIP-client-for-Arduino

ソース

/*
 *  NTRIP client for Arduino Ver. 1.0.0 
 *  NTRIPClient Sample
 *  Request Source Table (Source Table is basestation list in NTRIP Caster)
 *  Request Reference Data 
 * 
 * 
 */
//#include <ESP8266WiFi.h>  //Need for ESP8266
# include <WiFi.h>           //Need for ESP32 
# include "NTRIPClient.h"

//M5stack
# include <M5Stack.h>
# include <M5StackUpdater.h>

const char* ssid     = "your_ssid";
const char* password = "your_password";

char* host = "ntrip caster host";
int httpPort = 2101; //port 2101 is default port of NTRIP caster
char* mntpnt = "ntrip caster's mountpoint";
char* user   = "ntrip caster's client user";
char* passwd = "ntrip caster's client password";
NTRIPClient ntrip_c;

void setup() {
  M5.begin();
  Wire.begin();
  if(digitalRead(BUTTON_A_PIN) == 0) {
    Serial.println("Will Load menu binary");
    updateFromFS(SD);
    ESP.restart();
  }  
  // put your setup code here, to run once:
  Serial.begin(115200);
  delay(10);
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  
  Serial.println("Requesting SourceTable.");
  if(ntrip_c.reqSrcTbl(host,httpPort)){
    char buffer[512];
    delay(5);
    while(ntrip_c.available()){
      ntrip_c.readLine(buffer,sizeof(buffer));
      Serial.print(buffer); 
    }
  }
  else{
    Serial.println("SourceTable request error");
  }
  Serial.print("Requesting SourceTable is OK\n");
  ntrip_c.stop(); //Need to call "stop" function for next request.
  
  Serial.println("Requesting MountPoint's Raw data");
  if(!ntrip_c.reqRaw(host,httpPort,mntpnt,user,passwd)){
    delay(15000);
    ESP.restart();
  }
  Serial.println("Requesting MountPoint is OK");

  
}

void loop() {
  // put your main code here, to run repeatedly:
  while(ntrip_c.available()) {
        char ch = ntrip_c.read();        
        Serial.print(ch);
        
  }
}

電気的なこと

Trimble等のGPS装置にRTCM3を流す場合、M5Stackから出てくる信号をRS232に変換する必要があります。
https://www.amazon.co.jp/dp/B00OPTOKI0/