main.cpp

#include "mbed.h"
#include "pb.h"
#include "pb_encode.h"
#include "pb_decode.h"
#include "threeaxis.pb.h"
#include "MODSERIAL.h"

MODSERIAL pc(USBTX, USBRX, "modser"); //modified modser lib to be able to input custom stream

int main() {
    pc.baud(115200);
    gyro_message GyroOut, GyroIn;
    
    pc.claim();
    uint8_t bufferout[150];
    uint8_t bufferin[150];
    
    pb_ostream_t streamout = pb_ostream_from_buffer(bufferout, sizeof(bufferout));

    GyroOut.X=1.1;
    GyroOut.Y=2.1;
    GyroOut.Z=3.1;
    pc.printf("starting..\r\n");
    while(1){
        GyroOut.X+=0.1;
        GyroOut.Y+=0.2;
        GyroOut.Z+=0.3;
        
        pc.printf("Raw values: x: %4.2f, y: %4.2f, z: %4.2f\r\n", GyroOut.X, GyroOut.Y, GyroOut.Z); //print values before encoding
        
        if (pb_encode(&streamout, gyro_message_fields, &GyroOut)) { //encode message
            pc.printf("%s\r\n", bufferout); //print encoded message
        }
        
        else { //print error message if encoding fails
            pc.printf("Encoding failed: %s\n", PB_GET_ERROR(&streamout));
            return 0;
        }
        
        pc.printf("decoding...\r\n");
        pb_istream_t streamin = pb_istream_from_buffer(bufferin, sizeof(bufferin)); //create input stream
        for(int i=0;i<=streamout.bytes_written;i++) //copy output buffer to input buffer
            bufferin[i]=bufferout[i];
        if (pb_decode(&streamin, gyro_message_fields, &GyroIn)) { //decode message
            pc.printf("Decoded values: x: %4.2f, y: %4.2f, z: %4.2f\r\n", GyroIn.X, GyroIn.Y, GyroIn.Z); //print decoded values
        }
        
        else { //print error message if decoding fails
            pc.printf("Decoding failed: %s\n", PB_GET_ERROR(&streamin));
            return 0;
        }
        wait(1);
    }
}

/* Encode our message */
    {
        /* Allocate space on the stack to store the message data.
         *
         * Nanopb generates simple struct definitions for all the messages.
         * - check out the contents of simple.pb.h! */
        SensorData message;
        
        /* Create a stream that will write to our buffer. */
        pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));
        
        /* Fill in the tilt angle from p */
        message.tilt_angle = p;
        //pc.printf("message contains %f\n", message.tilt_angle);
        
        /* Now we are ready to encode the message! */
        status = pb_encode(&stream, SensorData_fields, &message);
        message_length = stream.bytes_written;

        
            for (int i = 0; i < sizeof(buffer); i++) {
            pc.putc(buffer[i]);

            }

        
        /* Then just check for any errors.. */
        if (!status)
        {
            pc.printf("Encoding failed: %s\n", PB_GET_ERROR(&stream));
            return 1;
        }

    }

while(1) {     
        if(device.readable()) {
 
            c = device.getc();
            buffer[i] = c;
            i++;
            i = i % 128;
                        
            // Create a stream that reads from the buffer. 
                
            if (i == 127){
                pb_istream_t stream = pb_istream_from_buffer(buffer, message_length);
        
                //Now we are ready to decode the message. 
                status = pb_decode(&stream, SensorData_fields, &message);
        
                // Check for errors... 
                if (!status)
                {
                    pc.printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
                    return 1;
                }
        
                // Print the data contained in the message. 
                pc.printf("Your lucky number was %f!\n", message.tilt_angle);
            }
        }     
    }