Go Down

Topic: Serial.write error when sending an array (Read 2271 times) previous topic - next topic


the following code has a compiler error, which I don't quite understand

Code: [Select]

int serialArrayOne[]  = {1,2,3,4,5,6,7,8};

void setup()

void loop()

error is:
sketch_jan15a.cpp: In function 'void loop()':
sketch_jan15a.cpp:19:32: error: no matching function for call to 'HardwareSerial::write(int [8], int)'
/usr/share/arduino/hardware/arduino/cores/arduino/HardwareSerial.h:58:20: note: candidates are: virtual size_t HardwareSerial::write(uint8_t)
/usr/share/arduino/hardware/arduino/cores/arduino/Print.h:50:20: note:                 virtual size_t Print::write(const uint8_t*, size_t)
/usr/share/arduino/hardware/arduino/cores/arduino/Print.h:49:12: note:                 size_t Print::write(const char*)

The manual says
Serial.write(buf, len)
buf: an array to send as a series of bytes
len: the length of the buffer

Anyone care to enlighten me


Coding Badly

From the perspective of Serial.write, a "buffer" is an array of bytes (uint8_t or byte).  This...

Code: [Select]
int serialArrayOne[]  = {1,2,3,4,5,6,7,8};

...is an array of integers (int).

This sends the array as you have defined it...

Code: [Select]
 Serial.write( (uint8_t*)serialArrayOne, sizeof(serialArrayOne) );

This defines serialArrayOne as a "buffer"...

Code: [Select]
byte serialArrayOne[]  = {1,2,3,4,5,6,7,8};


Cheers for that.
Coming from a 8bit assembly world, C can be a bit hard to to interpret at time
int used to be a byte for me

getting there

Nick Gammon

Code: [Select]
Serial.write( (uint8_t*)serialArrayOne, sizeof(serialArrayOne) );

That, however, is unlikely to send your ints in a way you expect. It is "casting" them to a different data type.

If you want to send those ints (16-bit signed numbers) as such, it would be better in your case to set up a loop, and in that loop do a Serial.print of each element, with something in-between (like a space, comma, newline, etc.).
Please post technical questions on the forum, not by personal message. Thanks!

More info:

Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131