hello everyone
im having a hard time coming up with code for getting multiple floats from one char array. I get one sentence from radio module that looks somethink like this "2800V6942I2953T000S" and ends with \0. I want to get numbers between letters and asign them to correct value based on letter after number. my current code looks like this but isnt working
void decodeInformation() {
int counter = 0;
for (int x = 0; x <= sizeof(information); x++) {
if (information[x] != "U" || information[x] != "I" || information[x] != "T" || information[x] != "S") {
buff[counter] = information[x];
}
else {
switch (information[x]) {
case 'U': skateBatVoltage = atof(buff); skateBatVoltage = skateBatVoltage / 100;break;
case 'I': skateCurrent = atof(buff); skateCurrent = skateCurrent / 100; break;
case 'T': temperature = atof(buff); temperature = temperature / 100; break;
case 'S': skateSpeed = atof(buff); skateSpeed = skateSpeed / 100; break;
default: break;
}
counter = 0;
buff[0] = '\0';
}
}
}
any help is appreciated 
You never increment counter and you don’t place a ‘\0’ in buff before you atof it.
If that is your code, not just what it looks like.
a7
oh i see. thanks i will try it
Isn't working is the most terrible phrase. Explain what is does and what you expected.
And for better help, make it into a mcve. For all we know 'buffer' is just 1 char big.
Also, why to a float? Values in the string are clearly no floats. And if the micro is an 8-bit (Uno etc), try to avoid float and just store it and know when you want to use it the value is 100 times "to big".
i modified a code a bit, added serial prints to debug,heres code
void decodeInformation() {
Serial.println(information);
Serial.println(sizeof(information));
int counter = 0;
for (int x = 0; x <= sizeof(information); x++) {
if (information[x] != 'U' || information[x] != 'I' || information[x] != 'T' || information[x] != 'S') {
buff[counter] = information[x];
Serial.println(buff[counter]);
Serial.println(counter);
Serial.println(x);
counter++;
}
else {
strcat(buff, '\0');
switch (information[x]) {
case 'U': skateBatVoltage = atof(buff); skateBatVoltage = skateBatVoltage / 100;Serial.print("skateBatVoltage");Serial.println(skateBatVoltage);break;
case 'I': skateCurrent = atof(buff); skateCurrent = skateCurrent / 100;Serial.print("skateCurrent");Serial.println(skateCurrent); break;
case 'T': temperature = atof(buff); temperature = temperature / 100;Serial.print("temperature");Serial.println(temperature); break;
case 'S': skateSpeed = atof(buff); skateSpeed = skateSpeed / 100;Serial.print("skateSpeed");Serial.println(skateSpeed); break;
default: break;
}
counter = 0;
strcpy(buff,'\0');
}
}
}
and here is output from serial monitor
2500U6942I2953T0S - full message
18 - sizeof message
2 - buff[counter]
0 - counter
0 - x
5
1
1
0
2
2
0
3
3
U
4
4
6
5
5
9
6
6
4
7
7
2
8
8
I
9
9
2
10
10
9
11
11
5
12
12
3
13
13
T
14
14
0
15
15
S
16
16
it looks like the if condition is always true, but i dont know why
NO! So close…
You can't strcat to an unterminated string.
strcat(buff, '\0'); // No!
instead do
buff[counter] = '\0';
a7
thanks, replaced it, still acting same...
void decodeInformation() {
Serial.println(information);
Serial.println(sizeof(information));
int counter = 0;
for (int x = 0; x <= sizeof(information); x++) {
if (information[x] != 'U' || information[x] != 'I' || information[x] != 'T' || information[x] != 'S') {
buff[counter] = information[x];
Serial.println(buff[counter]);
Serial.println(counter);
Serial.println(x);
counter++;
}
else {
buff[counter] = '\0';
switch (information[x]) {
case 'U': skateBatVoltage = atof(buff); skateBatVoltage = skateBatVoltage / 100;Serial.print("skateBatVoltage");Serial.println(skateBatVoltage);break;
case 'I': skateCurrent = atof(buff); skateCurrent = skateCurrent / 100;Serial.print("skateCurrent");Serial.println(skateCurrent); break;
case 'T': temperature = atof(buff); temperature = temperature / 100;Serial.print("temperature");Serial.println(temperature); break;
case 'S': skateSpeed = atof(buff); skateSpeed = skateSpeed / 100;Serial.print("skateSpeed");Serial.println(skateSpeed); break;
default: break;
}
counter = 0;
strcpy(buff,'\0');
}
}
}
for (int x = 0; x <= sizeof(information); x++)
Why not
for (int x = 0; x < strlen(information); x++) ?
You can't strcpy() from a char as well (as it's an unterminated string as well). No need to clear the buffer anyway.
My implementation including debug
char buffer[100];
byte bufferIndex = 0;
long skateBatVoltage, skateCurrent, temperature, skateSpeed = 0;
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
}
void loop() {
if(Serial.available()){
if(Serial.peek() == '\n'){
Serial.read();
buffer[bufferIndex++] = '\0';
Serial.print("Buffer: ");
Serial.println(buffer);
decodeInformation(buffer);
Serial.print("skateBatVoltage: ");
Serial.println(skateBatVoltage);
Serial.print("skateCurrent: ");
Serial.println(skateCurrent);
Serial.print("temperature: ");
Serial.println(temperature);
Serial.print("skateSpeed: ");
Serial.println(skateSpeed);
bufferIndex = 0;
}
else{
buffer[bufferIndex++] = Serial.read();
}
}
}
void decodeInformation(char str[]){
char* pnt;
while(*str){
long value = strtol(str, &pnt, 10);
Serial.print("Value: ");
Serial.println(value);
Serial.print("Remain: ");
Serial.println(pnt);
Serial.print("at: ");
Serial.println((uint16_t)pnt);
Serial.print("Next char: 0x");
Serial.println((uint8_t)pnt[0], HEX);
if(pnt != str && *pnt){
Serial.println("Set var!");
switch (pnt[0]) {
case 'U':
skateBatVoltage = value;
break;
case 'I':
skateCurrent = value;
break;
case 'T':
temperature = value;
break;
case 'S':
skateSpeed = value;
break;
default:
//null
Serial.println("or not.... SKIP!");
break;
}
}
str = ++pnt;
}
}
alto777:
NO! So close…
You can't strcat to an unterminated string.
strcat(buff, '\0'); // No!
Also, that would be "strchr", because "strcat" expects two char pointers.
But, as noted, you shouldn't use either on an unterminated buffer.
for (int x = 0; x <= sizeof(information); x++)
I suspect that that is wrong; you're reading data outside information. Without seeing the rest of your code, I can't be sure but you might very well write outside the bounds of buff.
strcpy(buff, '\0');
No idea what it will do but that's also wrong. strcpy takes a variable and a NUL terminated character array as arguments. If you want to clear buff, use one of the two below
buff[0] = '\0';
memset(buff, '\0', sizeof(buff));
septillion:
You can't strcpy() from a char as well (as it's an unterminated string as well). No need to clear the buffer anyway.
My implementation including debug
char buffer[100];
byte bufferIndex = 0;
long skateBatVoltage, skateCurrent, temperature, skateSpeed = 0;
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
}
void loop() {
if(Serial.available()){
if(Serial.peek() == '\n'){
Serial.read();
buffer[bufferIndex++] = '\0';
Serial.print("Buffer: ");
Serial.println(buffer);
decodeInformation(buffer);
Serial.print("skateBatVoltage: ");
Serial.println(skateBatVoltage);
Serial.print("skateCurrent: ");
Serial.println(skateCurrent);
Serial.print("temperature: ");
Serial.println(temperature);
Serial.print("skateSpeed: ");
Serial.println(skateSpeed);
bufferIndex = 0;
}
else{
buffer[bufferIndex++] = Serial.read();
}
}
}
void decodeInformation(char str[]){
char* pnt;
while(*str){
long value = strtol(str, &pnt, 10);
Serial.print("Value: ");
Serial.println(value);
Serial.print("Remain: ");
Serial.println(pnt);
Serial.print("at: ");
Serial.println((uint16_t)pnt);
Serial.print("Next char: 0x");
Serial.println((uint8_t)pnt[0], HEX);
if(pnt != str && *pnt){
Serial.println("Set var!");
switch (pnt[0]) {
case 'U':
skateBatVoltage = value;
break;
case 'I':
skateCurrent = value;
break;
case 'T':
temperature = value;
break;
case 'S':
skateSpeed = value;
break;
default:
//null
Serial.println("or not.... SKIP!");
break;
}
}
str = ++pnt;
}
}
thank you so much for help