oscilloscope things

examples/rtic_bare6.rs

@@ -18,7 +18,8 @@ use stm32f4xx_hal::{
     stm32::{self, GPIOC, RCC},
 };
 
-const OFFSET: u32 = 24_000_000;
+//const OFFSET: u32 = 24_000_000;
+const OFFSET: u32 = 8_000_000;
 
 #[rtic::app(device = stm32f4xx_hal::stm32, monotonic = rtic::cyccnt::CYCCNT, peripherals = true)]
 const APP: () = {
@@ -58,11 +59,11 @@ const APP: () = {
         // let _clocks = rcc.cfgr.freeze();
 
         // Set up the system clock. 48 MHz?
-        let _clocks = rcc
-            .cfgr
-            .sysclk(48.mhz())
-            .pclk1(24.mhz())
-            .freeze();
+        // let _clocks = rcc
+        //     .cfgr
+        //     .sysclk(48.mhz())
+        //     .pclk1(24.mhz())
+        //     .freeze();
 
         // let _clocks = rcc
         //     .cfgr
@@ -71,12 +72,12 @@ const APP: () = {
         //     .pclk2(64.mhz())
         //     .freeze();
         //
-        // let _clocks = rcc
-        //     .cfgr
-        //     .sysclk(84.mhz())
-        //     .pclk1(42.mhz())
-        //     .pclk2(64.mhz())
-        //     .freeze();
+        let _clocks = rcc
+            .cfgr
+            .sysclk(84.mhz())
+            .pclk1(42.mhz())
+            .pclk2(64.mhz())
+            .freeze();
 
         // pass on late resources
         init::LateResources {
@@ -138,7 +139,7 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
     // otyper reset state push/pull, in reset state (don't need to change)
 
     // ospeedr 0b11 = very high speed
-    gpioc.ospeedr.modify(|_, w| w.ospeedr9().very_high_speed());
+    gpioc.ospeedr.modify(|_, w| w.ospeedr9().low_speed());
 }
 
 // 0. Background reading:
@@ -207,7 +208,7 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    `rcc.cfgr.sysclk(84.mhz()).pclk1(42.mhz()).pclk2(64.mhz()).freeze();`
 //
-//    ** your answer here **
+//    Nothing?
 //
 //    Start `stm32cubemx` and select or create a project targeting stm32f401.
 //    Go to the graphical clock configuration view.
@@ -255,11 +256,11 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    Compute the value of SYSCLK based on the oscilloscope reading
 //
-//    ** your answer here **
+//    about 4MHz
 //
 //    What is the peak to peak (voltage) reading of the signal?
 //
-//    ** your answer here **
+//    between 4.7 - 4.8, alternating between them
 //
 //    Make a folder called "pictures" in your git project.
 //    Make a screen dump or photo of the oscilloscope output.
@@ -283,15 +284,15 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    What is the frequency of MCO2 read by the oscilloscope?
 //
-//    ** your answer here **
+//    about 12 MHz
 //
 //    Compute the value of SYSCLK based on the oscilloscope reading.
 //
-//    ** your answer here **
+//    about 48 MHz
 //
 //    What is the peak to peak reading of the signal?
 //
-//    ** your answer here **
+//    4.9V
 //
 //    Make a screen dump or photo of the oscilloscope output.
 //    Save the the picture as "bare_6_48mhz_high_speed".
@@ -326,11 +327,11 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    Did the frequency change in comparison to assignment 5?
 //
-//    ** your answer here **
+//    No it did not.
 //
 //    What is the peak to peak reading of the signal (and why did it change)?
 //
-//    ** your answer here **
+//    about 3.6V. 
 //
 //    Make a screen dump or photo of the oscilloscope output.
 //    Save the the picture as "bare_6_48mhz_low_speed".
@@ -343,11 +344,11 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    Does the code compile?
 //
-//    ** your answer here **
+//    It does compile.
 //
 //    What happens at run-time?
 //
-//    ** your answer here **
+//    Panik!!!!
 //
 //    Try setting the clocks according to:
 //
@@ -355,11 +356,11 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    Does the code compile?
 //
-//    ** your answer here **
+//    It work
 //
 //    What happens at run-time?
 //
-//    ** your answer here **
+//    It work
 //
 //    Is that a correct?
 //