Now i can do ssh from pi5 to ubuntu-laptop on 192.168.1.145 even when i disconnected form wifi on ubuntu-laptop.
root@lp-arm-5:~# ssh root@192.168.1.145
root@192.168.1.145's password:
Welcome to Ubuntu 24.04.2 LTS (GNU/Linux 6.17.0-14-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/pro
Expanded Security Maintenance for Applications is not enabled.
376 updates can be applied immediately.
364 of these updates are standard security updates.
To see these additional updates run: apt list --upgradable
89 additional security updates can be applied with ESM Apps.
Learn more about enabling ESM Apps service at https://ubuntu.com/esm
Last login: Sat Jul 25 18:59:08 2026 from 192.168.10.118
#include <WiFi.h>
const char *ssid = "wifi";
const char *password = "pass";
// GPS UART
HardwareSerial GPS(2); // UART2
// Standard NMEA TCP port
WiFiServer server(10110);
// Allow multiple clients
WiFiClient clients[5];
String line;
void setup() {
Serial.begin(115200);
// GPS on GPIO21 (RX), GPIO22 (TX)
GPS.begin(9600, SERIAL_8N1, 21, 22);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
Serial.print("Connecting");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println();
Serial.print("Connected: ");
Serial.println(WiFi.localIP());
server.begin();
server.setNoDelay(true);
Serial.println("NMEA TCP server started on port 10110");
}
void loop() {
// Accept new clients
if (server.hasClient()) {
for (int i = 0; i < 5; i++) {
if (!clients[i] || !clients[i].connected()) {
if (clients[i])
clients[i].stop();
clients[i] = server.available();
clients[i].setNoDelay(true);
Serial.printf("Client %d connected\n", i);
break;
}
}
// No room
WiFiClient reject = server.available();
reject.stop();
}
// Read GPS
while (GPS.available()) {
char c = GPS.read();
// Echo to USB serial
Serial.write(c);
line += c;
if (c == '\n') {
// Send complete NMEA sentence to all clients
for (int i = 0; i < 5; i++) {
if (clients[i] && clients[i].connected()) {
clients[i].print(line);
if (clients[i].getWriteError()) {
clients[i].stop();
}
}
}
line.clear();
// Prevent runaway if malformed data
if (line.length() > 256)
line.clear();
}
}
}
xgps to view data
apt install gpsd gpsd-clients
nc ESP-IP 10110
#OR
gpsd tcp://192.168.1.150:10110
#lauch
xgps
#or
sudo systemctl stop gpsd.socket gpsd
gpsd -N -n -D 5 tcp://192.168.10.196:10110
gpspipe -r
#lauch
xgps
#check time of laptop
home@home:~$ ntpdate -q 192.168.10.196
2026-07-28 17:58:10.0 (+0530) -1.950956 +/- 0.001631 192.168.10.196 s1 no-leap
Your computer's clock is about -1.950956 seconds ahead of the GPS-based NTP server. To match the GPS time, your clock would need to move backward by about -1.950956 seconds.
systemctl enable --now chrony
@home: timedatectl
Local time: Tue 2026-07-28 18:09:42 IST
Universal time: Tue 2026-07-28 12:39:42 UTC
RTC time: Tue 2026-07-28 12:39:42
Time zone: Asia/Kolkata (IST, +0530)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no
@home:~$ chronyc tracking
Reference ID : 41007738 (ec2-65-0-119-56.ap-south-1.compute.amazonaws.com)
Stratum : 5
Ref time (UTC) : Tue Jul 28 12:41:44 2026
System time : 0.000236698 seconds fast of NTP time
Last offset : +0.000414969 seconds
RMS offset : 0.000378138 seconds
Frequency : 14.685 ppm fast
Residual freq : +1.339 ppm
Skew : 21.187 ppm
Root delay : 0.010673190 seconds
Root dispersion : 0.000975857 seconds
Update interval : 64.2 seconds
Leap status : Normal
chronyc sources -v
