Commit 4fe5f837 authored by Henrik Tjäder's avatar Henrik Tjäder

Merge branch 'master' of gitlab.henriktjader.com:pln/rtfm-app

parents 447681d5 69644c45
//! Simple access to gpio
//#![deny(unsafe_code)]
#![feature(proc_macro)]
#![no_std]
extern crate cortex_m;
extern crate cortex_m_rtfm as rtfm;
extern crate stm32f40x;
#[macro_use]
extern crate cortex_m_debug;
use rtfm::app;
app! {
device: stm32f40x,
}
fn wait(i: u32) {
for _ in 0..i {
cortex_m::asm::nop(); // no operation (cannot be optimized out)
}
}
// see the Reference Manual RM0368 (www.st.com/resource/en/reference_manual/dm00096844.pdf)
// rcc, chapter 6
// gpio, chapter 8
fn init(p: init::Peripherals) {
ipln!("OUTPUT MCO2 on PC9/CN10-1)");
sprintln!("OUTPUT MCO2 on PC9/CN10-1)");
// output MCO2 to pin PC9
//
// mco2 : SYSCLK = 0b00
// mcopre : divide by 4 = 0b110
p.RCC
.cfgr
.modify(|_, w| unsafe { w.mco2().bits(0b00).mco2pre().bits(0b110) });
// power on GPIOC, RM0368 6.3.11
p.RCC.ahb1enr.modify(|_, w| w.gpiocen().set_bit());
// MCO_2 alternate function AF0, STM32F401xD STM32F401xE data sheet
// table 9
// AF0, gpioc reset value = AF0
// configure PC9 as alternate function 0b10, RM0368 6.2.10
p.GPIOC
.moder
.modify(|_, w| unsafe { w.moder9().bits(0b10) });
// otyper reset state push/pull
// ospeedr 0b11 = high speed
p.GPIOC
.ospeedr
.modify(|_, w| unsafe { w.ospeedr9().bits(0b11) });
// power on GPIOA, RM0368 6.3.11
p.RCC.ahb1enr.modify(|_, w| w.gpioaen().set_bit());
// configure PA5 as output, RM0368 8.4.1
p.GPIOA.moder.modify(|_, w| w.moder5().bits(1));
// loop {
// // set PA5 high, RM0368 8.4.6
// p.GPIOA.odr.modify(|_, w| w.odr5().bit(true));
// wait(10_000);
// // set PA5 low, RM0368 8.4.6
// p.GPIOA.odr.modify(|_, w| w.odr5().bit(false));
// wait(10_000);
// }
// rewrite the above code to have the GPIO as output
// and alter the data output through the BSRR register
// this is more efficient as the read register (in modify)
// is not needed.
loop {
// set PA5 high, RM0368 8.4.7
p.GPIOA.bsrr.write(|w| w.bs5().set_bit());
wait(10_000);
// set PA5 low, RM0368 8.4.7
p.GPIOA.bsrr.write(|w| w.br5().set_bit());
wait(10_000);
}
}
#[inline(never)]
fn idle() -> ! {
loop {
rtfm::wfi();
}
}
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