Particle - GPS Device - Publish - String or StringList to google cloud

[paul41]

I am looking to send some GPS co-ordinates and save these into google cloud database.

Previously on the particle device i have done this successfully sending only one value using;

data = analogValue
Particle.publish(“my_event”), data, PRIVATE);

However, for my GPS i want to send both latitude and longitude values.

What is the best method of publishing two values as opposed to just one?

[nrobinson2000]

It depends on how you would like to parse the string on the receiving end. JSON and CSV are both popular formats for sending a series of values in a single publish.

Essentially you would need a char buffer (c-string) to format the data into, and then publish that buffer. There are plenty of examples of using snprintf() here on the forum.

// Buffer to store the generated message
char message[255];

// Example using two doubles and an int
double data1 = 123.4;
double data2 = 56.78;
int data3 = 42;

// CSV formatting
snprintf(message, sizeof(message), "%.2f,%.2f,%d", data1, data2, data3);

// JSON formatting
snprintf(message, sizeof(message), "{\"data1\":%.2f, \"data2\":%.2f, \"data3\":%d}", data1, data2, data3);

// Publish the buffer
Particle.publish("my_event", message, PRIVATE);

[paul41]

Thank you very much!!! That is so much appreciated, i will update on how i get on