Welcome in the forum, Christof!
/* For GCC compiler revise _write() function for printf functionality */
int _write(int file, char *ptr, int len)
file = file;
for (i = 0; i < len; i++)
I am using this.
As pointed out above, when linking with newlib-nano instead of newlib this function is never called. When linking with newlib it works flawlessly.
I would suggest you to create a support case to get that answered. At top of this page "Design Support -> Create a Support Case"
Would be nice when you keep us informed here in the forum.
In addition I have placed a question to the ARM guys who are maintainers of the newlib-nano. But I guess the behavior is very depending on how 3rt paties (in this case Cypress) are building this library (we have no sources from Cypress)
Cypress has very tight contact to ARM, there is Heinz Holzapfel (email@example.com) sitting in Portland who might help you. I would suggest to send the Cypress case number to him together with a bit of explanation.
increasing heap size solved the problem.
Original answer Cypress support:
In default PSoC 5LP projects will be having a heap size of 0x80, this is to decrease the project size. For newlib nano to use the printf you may need to have more heap size. Can you try increasing it to 0x200 or more. [*.cydwr file -> Systems tab]
HTH others as well,