ESP8266 Community Forum

- Tue Apr 21, 2015 4:22 pm #15233

People say its slower, that may be, but I can get, for example, over 10,000 sin() calculations per second, which is well fast enough for what I'm working on.

It's slower (by factor of 12..13) only for the first time. When code gets to the FLASH mapping cache it runs as fast as from IRAM. If your loop is tight enough to fit into 32KBytes of FLASH cache it should be fast.

- Tue Apr 21, 2015 9:15 pm #15248 I think it will work well for my application.

I'll be publishing it on github when i'm done.

/Kevin

- Thu Apr 23, 2015 1:53 pm #15406 I want to use atan and sqrt
I rebuild compiler branch lx106-g++, but an error happens

build/app_app.a(user_main.o):(.irom0.text+0xe0): undefined reference to `sqrt'
build/app_app.a(user_main.o):(.irom0.text+0xe8): undefined reference to `atan'

Can you tell me the steps to use this functions?

Thanks

- Fri Apr 24, 2015 1:16 pm #15520

build/app_app.a(user_main.o):(.irom0.text+0xe0): undefined reference to `sqrt'
build/app_app.a(user_main.o):(.irom0.text+0xe8): undefined reference to `atan'

Start with adding -lm to your linker options to link with math library.