Comments (3)
exception
has a special meaning for Cortex-M CPUs. Some exceptions are used for error status', but more generally they are just built-in interrupts.
This is the exception number definition for ARMv6-M: https://developer.arm.com/documentation/ddi0419/c/System-Level-Architecture/System-Level-Programmers--Model/ARMv6-M-exception-model/Exception-number-definition?lang=en
2 is HardFault
, that occurs only when there's an error condition, but 15 is SysTick, and that occurs as part of normal operation. All the interrupts added by ST then get allocation to number 16+
from stm32f0xx-hal.
I gave it a quick skim, it looks like the SysTick is simply used to calculate the speed of the encoder: stm32f1xx_it.c#L197
The actual position comes from a different mechanism, HAL_TIM_IC_CaptureCallback
(if I am reading that right, I did skim this fairly quickly 😅 )
Assuming you have that position the SysTick handler could be written in rust along the lines of:
// probably missing some use statements, I didn't actually compile this.
use cortex_m_rt::{entry, exception};
static OLDPOS: i16 = 0;
static INDX: i32 = 0;
#[exception]
fn SysTick() {
unsafe {
INDX += 1;
if (INDX == 500) {
SPEED = ((POSITION - OLDPOS) * 2);
OLDPOS = POSITION;
INDX = 0;
}
}
// whatever else here
}
#[entry]
fn main() -> ! {
let p = cortex_m::Peripherals::take().unwrap();
let mut syst = p.SYST;
// configures the system timer to trigger a SysTick exception every second
syst.set_clock_source(SystClkSource::Core);
// CPU clock of 8 MHz
syst.set_reload(8_000_000);
syst.clear_current();
syst.enable_counter();
syst.enable_interrupt();
loop {
compiler_fence(SeqCst);
}
}
Actually getting the position is a bit more effort that I don't know about off the top of my head.
That C example you linked isn't too big, you could probably recreate that using the PAC to get started.
from stm32f0xx-hal.
@newAM Thanks very much for this!
I saw in the examples that the #[exception]
macro was used, but based on the comments it seems like it 's only called when an error occurs in the interrupt. But based on your example, it's the interrupt routine itself?
from stm32f0xx-hal.
Related Issues (20)
- Why does configuring a GPIO require a critical section in this hal? HOT 2
- Have PA9/10/11/12 USB pins automatically remap? HOT 5
- cannot find value `RCC_PLLSRC_PREDIV1_SUPPORT` HOT 5
- SPI blocking transfers do not wait for completion. HOT 13
- First write on I2C bus never NACK's HOT 15
- bxcan/defmt version conflict HOT 3
- SPI on 0.17.1 is broken HOT 3
- More precise units for timers. HOT 1
- USART: Support half-duplex mode HOT 1
- rcc error HOT 1
- Flash Driver HOT 2
- Improve API to allow having an array of Analog pins HOT 1
- Cannot acknowledge timer interrupt flag
- Confused by features on f03x HOT 1
- Disabling GPIO clock HOT 1
- PWM on Special Channels? HOT 3
- Quadrature Encoder Interface
- Using timer1 channel 4 for ADC triggering
- STM32F072C8T6 -- wrong binary size? HOT 1
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from stm32f0xx-hal.