Modified jerk planner to use no_std and custom sqrt and cbrt routines. These routines do not seem to work yet

firmware/jerk_control/src/bin/sqrt_test.rs

@@ -0,0 +1,36 @@
+fn ulp(f: f32) -> f32 {
+    f32::from_bits((f.to_bits() & 0x7f80_0000) - 0x0b80_0000)
+}
+
+fn fn_err(actual: f32, calc: f32) -> f32 {
+    (calc - actual).abs() / actual
+}
+
+
+fn test_all(fname: &str, actual: fn(f32) -> f32, calc: fn(f32) -> f32) {
+    let mut max_err = 0f32;
+    let mut max_err_value = 0f32;
+    for i in (0x00c0_0000..0x0f7f_ffffu32).map(f32::from_bits) {
+        // range of normalized floats...
+        let err = fn_err(actual(i), calc(i));
+        if err > max_err {
+            max_err = err;
+            max_err_value = i;
+	    }
+	}
+
+    let max_err_pct = max_err * 100f32;
+    println!("{}: {}% @ {}", fname, max_err_pct, max_err_value);
+    println!(
+        "Value:      0x{:08x}\n
+        Calculated: 0x{:08x}\n
+        Actual:     0x{:08x}",
+        max_err_value.to_bits(),
+        calc(max_err_value).to_bits(), actual(max_err_value).to_bits())
+}
+
+
+fn main() {
+    // test_all("sqrt", f32::sqrt, jerk_control::math_ext::Roots::sqrt);
+    test_all("cbrt", f32::cbrt, jerk_control::math_ext::Roots::cbrt);
+}

firmware/jerk_control/src/lib.rs

@@ -1,2 +1,6 @@
+// #![no_std]
+
 pub mod planner;
-pub mod executor;
+pub mod executor;
+
+pub mod math_ext;

firmware/jerk_control/src/planner.rs

@@ -4,6 +4,7 @@
 //! All of their derivations can be found in the motion-control.ipynb file.
 
 use core::num::Wrapping;
+use core::option::Option;
 
 pub struct Config {
     /// Max jerk, in mm/s^3
@@ -162,7 +163,7 @@ impl Planner {
             .clamp(0.0, (1u32 << 31) as f32);
         let step_size = config.step_size * 6. * tick_rate * tick_rate * tick_rate / config.j_max;
         if step_size > (u32::MAX / 2) as f32 {
-            eprintln!("Failed to configure planner: stepsize = {}", step_size);
+            //eprintln!("Failed to configure planner: stepsize = {}", step_size);
             return false;
         }
         self.a_max = a_max as u32;
@@ -212,7 +213,7 @@ impl Planner {
         let tv = (dx - ramp_dx) * 2 / s4v as u64;
         let tv = ((tv + 1) / 2) as u32;
 
-        eprintln!("ta={ta}, tj={tj}, tv={tv}");
+        //eprintln!("ta={ta}, tj={tj}, tv={tv}");
         let j_real = dir * 6;
         let mut segments = [Segment::default(); 8];
         let seg_params = [