Lpc1769 software floating point unit (FPU) - ( for printf family)

ramazan_kurban3 — Fri, 19 Jul 2019 18:40:46 GMT

I use gnu arm on eclipse ( lpc1769 m3 cortex ). I want to convert float value to string with sprintf but it doesnt work.

I add -u_printf_float to linker option but it is didnt work because m3 cortex has not hard FPU. Therefore i add -mfloat-abi=soft to linker option for use software FPU but it doesnt work. How can i solve this problem.

int main(void) {

    InitBoard();         float flt = 1.1;        char msg[256];        sprintf(msg , "number is %.3f ", flt);        while (1){             KC_UART_sendstring(LPC_UART0, msg);             delay_ms(500);        }}

Re: Lpc1769 software floating point unit (FPU) - ( for printf family)

Alice_Yang — Mon, 29 Jul 2019 06:37:52 GMT

Hello Ramazan Kurban,

Could you please show what's the data inside msg[] when it doesn't work。

I test on MCUXpresso IDE (it based on Eclipse), it seems can work well:

Alice

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Lpc1769 software floating point unit (FPU) - ( for printf family)

Re: Lpc1769 software floating point unit (FPU) - ( for printf family)