Please I'm having an issue where I need to split a payload coming from an energy meter into chunks of 5-bytes each that represent different values of line parameters. The payload length is 35 bytes as shown below.
{"01000008c502000008e90300000913040000001305000000310600000013070000001b0800000022090000006d0a000000040b000000940c000000290d0000006d0e0000002b0f00000096100000033511000003e6120000006513000003d91400000713150000137d1600000005";}
I would like it printed out this way after running the code.
phase A voltage: 01000008c5
phase B voltage: 02000008e9
phase C voltage: 0300000913
phase A current: 0400000013
phase B current: 0500000031
phase C current: 0600000013
powerfactor: 070000001b
active power A: 0800000022
active power B: 090000006d
active power C: 0a00000004
Apparent power A :0b00000094
Apparent power B: 0c00000029
Apparent power C: 0d0000006d
If anyone can assist with a sample code or point me in the right direction on how i can split this packet coming from a sensor into 5-bytes each and print it on a compiler. I just want to copy the packet from the sensor, paste it into the program and run. Using an array will require adding commas manually to separate the bytes which I don't want to do.
#include <stdio.h>
#include <string.h>
void split_payload(const char *payload_hex, size_t chunk_bytes)
{
// Each byte is represented by two hexadecimal characters.
size_t chunk_chars = chunk_bytes * 2;
size_t payload_len = strlen(payload_hex);
printf("Splitting the payload into %zu-byte chunks (chunks of %zu characters):\n\n", chunk_bytes, chunk_chars);
for (size_t i = 0; i < payload_len; i += chunk_chars)
{
// Use a loop to print each character of the chunk
for (size_t j = 0; j < chunk_chars; ++j)
{
if (i + j < payload_len)
{
printf("%c", payload_hex[i + j]);
}
}
printf("\n");
}
}
int main()
{
const char *payload_hex = "01000008c502000008e90300000913040000001305000000310600000013070000001b0800000022090000006d0a000000040b000000940c000000290d0000006d0e0000002b0f00000096100000033511000003e6120000006513000003d91400000713150000137d1600000005";
size_t bytes_per_chunk = 5;
split_payload(payload_hex, bytes_per_chunk);
return 0;
}
You want this:
...
const char* labels[] =
{ "phase A voltage:", "phase B voltage:", "phase C voltage:",
"phase A current:", "phase B current:", "phase C current:",
"active power A:", "active power B:", "active power C:",
"Apparent power A:", "Apparent power B:", "Apparent power C:",
"Reactive power A:", "Reactive power B:", "Reactive power C:",
"Whatever 1:", "Whatever 2:", "Whatever 3:",
"Whatever 4:", "Whatever 5:", "Whatever 6:", "Whatever 7:"
};
...
...
for (size_t i = 0; i < payload_len; i += chunk_chars)
{
printf("%s ", labels[i / chunk_chars]); // <<< add this to your code
// Use a loop to print each character of the chunk
...
The value i / chunk_chars varies from 0 to payload_len / chunk_chars by increments of 1.
So the first the loop is executed, it is 0, the second time it's 1 etc.
const char* labels[] = ... declares an array containing (roughly speaking) the different labels. labels[0] is the first label, labels[1] is the second label etc.