Adjust PID, RPM math (still not correct)

spinnyboy_rust/Cargo.lock

@@ -213,6 +213,15 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "discrete_pid"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d6406befa7a91e856133d660b608d13e8eb23d2a9df7b90c9a87339dd8b5558"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "document-features"
 version = "0.2.12"
@@ -1134,6 +1143,7 @@ name = "spinnyboy_rust"
 version = "0.1.0"
 dependencies = [
  "critical-section",
+ "discrete_pid",
  "embedded-hal 1.0.0",
  "esp-alloc",
  "esp-backtrace",