From db033c7ee6fa44400da46e0e7384b7e422d14cfc Mon Sep 17 00:00:00 2001
From: J / Jacob Babich <jacobbabichpublic+git@gmail.com>
Date: Sun, 17 Apr 2022 13:18:43 -0400
Subject: [PATCH] trying out uart and asm

---
 src/main.rs | 70 +++++++++++++++++++++++++++++++++++------------------
 1 file changed, 46 insertions(+), 24 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 0d69828..d374c29 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,13 +1,14 @@
 #![no_std]
 #![no_main]
 
-use core::ptr;
+use core::{arch::asm, ptr};
 
 use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch panics
 
 use cortex_m_rt::entry;
 use driver_and_task_library::{
-    setup_board, Function, Pin, Port, PortOptions, ReadablePinOptions, WritablePinOptions, H, L, UsableBoard, 
+    setup_board, Function, Pin, Port, PortOptions, ReadablePinOptions, UsableBoard,
+    WritablePinOptions, H, L,
 };
 
 const SYSCTL_RCGC1_R: *mut u32 = 0x400FE104 as *mut u32;
@@ -43,20 +44,26 @@ const PINS_0_AND_1: u32 = 0b0000_0011;
 fn uart0_init(board: UsableBoard) {
     unsafe {
         // activate UART0
-        ptr::write_volatile(SYSCTL_RCGC1_R, ptr::read_volatile(SYSCTL_RCGC1_R) | SYSCTL_RCGC1_UART0);
+        ptr::write_volatile(
+            SYSCTL_RCGC1_R,
+            ptr::read_volatile(SYSCTL_RCGC1_R) | SYSCTL_RCGC1_UART0,
+        );
         // activate port A
         // ptr::write_volatile(SYSCTL_RCGC2_R, ptr::read_volatile(SYSCTL_RCGC2_R) | SYSCTL_RCGC2_GPIOA);
         // ^ commented in favor of v
         board.setup_gpio_port(Port::A, PortOptions);
-        
+
         // disable UART while setting it up
-        ptr::write_volatile(UART0_CTL_R, ptr::read_volatile(UART0_CTL_R) & !UART_CTL_UARTEN);
-        
+        ptr::write_volatile(
+            UART0_CTL_R,
+            ptr::read_volatile(UART0_CTL_R) & !UART_CTL_UARTEN,
+        );
+
         // ignore: // IBRD = int(50,000,000 / (16 * 115,200)) = int(27.1267)
         // IBRD = int(16,000,000 / (16 * 115,200)) = int(8.680)
         // ptr::write_volatile(UART0_IBRD_R, 8);
         ptr::write_volatile(UART0_IBRD_R, 8);
-        
+
         // ignore: // FBRD = int(0.1267 * 64 + 0.5) = 8
         // FBRD = round(0.5104 * 64 ) = 33 --- that ain't the number you wrote but ok
         // ptr::write_volatile(UART0_FBRD_R, 44);
@@ -65,25 +72,32 @@ fn uart0_init(board: UsableBoard) {
         // 8 bit word length (no parity bits, one stop bit, FIFOs)
         // ptr::write_volatile(UART0_LCRH_R, UART_LCRH_WLEN_8|UART_LCRH_FEN);
         // 8 bit word length (no parity bits, one stop bit, no FIFOs)
-        ptr::write_volatile(UART0_LCRH_R, UART_LCRH_WLEN_8&!UART_LCRH_FEN);
-        
+        ptr::write_volatile(UART0_LCRH_R, UART_LCRH_WLEN_8 & !UART_LCRH_FEN);
+
         // enable UART since it's been set up
-        ptr::write_volatile(UART0_CTL_R, ptr::read_volatile(UART0_CTL_R) | UART_CTL_UARTEN);
-        
+        ptr::write_volatile(
+            UART0_CTL_R,
+            ptr::read_volatile(UART0_CTL_R) | UART_CTL_UARTEN,
+        );
+
         // enable alt funct on PA1-0
-        ptr::write_volatile(GPIO_PORTA_AFSEL_R, ptr::read_volatile(GPIO_PORTA_AFSEL_R) | PINS_0_AND_1);
+        ptr::write_volatile(
+            GPIO_PORTA_AFSEL_R,
+            ptr::read_volatile(GPIO_PORTA_AFSEL_R) | PINS_0_AND_1,
+        );
         // enable digital I/O on PA1-0
-        ptr::write_volatile(GPIO_PORTA_DEN_R, ptr::read_volatile(GPIO_PORTA_AFSEL_R) | PINS_0_AND_1);
+        ptr::write_volatile(
+            GPIO_PORTA_DEN_R,
+            ptr::read_volatile(GPIO_PORTA_AFSEL_R) | PINS_0_AND_1,
+        );
     }
 }
 
 fn uart0_out_char(c: u8) {
     loop {
-        let fr = unsafe {
-            ptr::read_volatile(UART0_FR_R)
-        };
+        let fr = unsafe { ptr::read_volatile(UART0_FR_R) };
 
-        if (fr & UART_FR_TXFF) == 0 { 
+        if (fr & UART_FR_TXFF) == 0 {
             break;
         }
     }
@@ -134,27 +148,35 @@ fn main() -> ! {
 
     rgb_led.write_all(cyan);
 
-    
     uart0_init(board);
 
     rgb_led.write_all(white);
 
     for _ in 0..2 {
-
-        
-        for c in ['H', 'a', 'y', '!', '\n', 'H', 'e', 'y', '!', '\n', 'H', 'e', 'y', '!', '\n', 'H', 'e', 'y', '!', '\n', ] {
+        for c in [
+            'H', 'a', 'y', '!', '\r', '\n', 'H', 'e', 'y', '!', '\r', '\n', 'H', 'e', 'y', '!',
+            '\r', '\n', 'H', 'e', 'y', '!', '\r', '\n',
+        ] {
             uart0_out_char(c as u8);
         }
-        
     }
-    uart0_out_string("Those example string!\n");
+    uart0_out_string("Those example string!\r\n");
 
     loop {
         match switches.read_all() {
-            [L, L] => rgb_led.write_all(white),
+            [L, L] => {
+                rgb_led.write_all(white);
+                uart0_out_string("Hey! You're pressing the button down!\r\n");
+            }
             [L, H] => rgb_led.write_all(blue),
             [H, L] => rgb_led.write_all(red),
             [H, H] => rgb_led.write_all(green),
         }
+
+        for _ in 0..1000000 {
+            unsafe {
+                asm!("nop");
+            }
+        }
     }
 }