ESP8266 Community Forum

- Tue Mar 17, 2015 9:12 pm #12148 I want to use the readvdd33() function that's being called in the NodeMCU firmware, but I get an implicit declaration error on compile. I guess it can't find the definition.

I'm not familiar enough with this stuff to fix it. Can anyone help? I'm using the esphttpd example code in CHERTS' dev kit.

- Tue Mar 17, 2015 9:50 pm #12151 Figured out it has to do with the compile order. If I throw in a declaration before the function that calls it, it compiles.

Code: Select alluint32_t readvdd33(void);

- Wed Mar 18, 2015 8:14 am #12176 Okay, so this works, but the question is...Is this the proper way to do it? Do I have to include declarations for all SDK system functions that I want to use?

- Wed Mar 18, 2015 8:21 am #12177

Do I have to include declarations for all SDK system functions that I want to use?

Yes. That's the normal way of using external functions in C.