diff --git a/Cargo.lock b/Cargo.lock
index abf6996..3cc8175 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -180,6 +180,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "derivative"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "derive_miniconf"
 version = "0.1.0"
@@ -195,7 +206,6 @@ name = "dsp"
 version = "0.1.0"
 dependencies = [
  "easybench",
- "libm",
  "miniconf",
  "ndarray",
  "num",
@@ -354,12 +364,6 @@ version = "0.2.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
 
-[[package]]
-name = "libm"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7d73b3f436185384286bd8098d17ec07c9a7d2388a6599f824d8502b529702a"
-
 [[package]]
 name = "log"
 version = "0.4.14"
@@ -517,6 +521,27 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "num_enum"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "226b45a5c2ac4dd696ed30fa6b94b057ad909c7b7fc2e0d0808192bced894066"
+dependencies = [
+ "derivative",
+ "num_enum_derive",
+]
+
+[[package]]
+name = "num_enum_derive"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c0fd9eba1d5db0994a239e09c1be402d35622277e35468ba891aa5e3188ce7e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "paste"
 version = "1.0.5"
@@ -740,14 +765,13 @@ dependencies = [
  "cortex-m-rtic",
  "dsp",
  "embedded-hal",
- "enum-iterator",
- "generic-array 0.14.4",
  "heapless 0.6.1",
  "log",
  "mcp23017",
  "miniconf",
  "minimq",
  "nb 1.0.0",
+ "num_enum",
  "paste",
  "rtt-logger",
  "rtt-target",
diff --git a/Cargo.toml b/Cargo.toml
index ba8094d..d90f682 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,11 +39,10 @@ cortex-m-rtic = "0.5.6"
 embedded-hal = "0.2.4"
 nb = "1.0.0"
 asm-delay = "0.9.0"
-enum-iterator = "0.6.0"
+num_enum = { version = "0.5.1", default-features = false }
 paste = "1"
 dsp = { path = "dsp" }
 ad9959 = { path = "ad9959" }
-generic-array = "0.14"
 miniconf = "0.1.0"
 shared-bus = {version = "0.2.2", features = ["cortex-m"] }
 serde-json-core = "0.3"
diff --git a/dsp/Cargo.toml b/dsp/Cargo.toml
index f9f680b..0f82bd2 100644
--- a/dsp/Cargo.toml
+++ b/dsp/Cargo.toml
@@ -5,7 +5,6 @@ authors = ["Robert Jördens <rj@quartiq.de>"]
 edition = "2018"
 
 [dependencies]
-libm = "0.2.1"
 serde = { version = "1.0", features = ["derive"], default-features = false }
 num = { version = "0.4.0", default-features = false }
 miniconf = "0.1"
diff --git a/src/hardware/afe.rs b/src/hardware/afe.rs
index 962c417..35b7d66 100644
--- a/src/hardware/afe.rs
+++ b/src/hardware/afe.rs
@@ -2,11 +2,12 @@ use miniconf::Miniconf;
 use serde::{Deserialize, Serialize};
 
 use core::convert::TryFrom;
-use enum_iterator::IntoEnumIterator;
+use num_enum::TryFromPrimitive;
 
 #[derive(
-    Copy, Clone, Debug, Serialize, Deserialize, IntoEnumIterator, Miniconf,
+    Copy, Clone, Debug, Serialize, Deserialize, TryFromPrimitive, Miniconf,
 )]
+#[repr(u8)]
 pub enum Gain {
     G1 = 0b00,
     G2 = 0b01,
@@ -32,20 +33,6 @@ impl Gain {
     }
 }
 
-impl TryFrom<u8> for Gain {
-    type Error = ();
-
-    fn try_from(value: u8) -> Result<Self, Self::Error> {
-        for gain in Gain::into_enum_iter() {
-            if value == gain as u8 {
-                return Ok(gain);
-            }
-        }
-
-        Err(())
-    }
-}
-
 impl<A0, A1> ProgrammableGainAmplifier<A0, A1>
 where
     A0: embedded_hal::digital::v2::StatefulOutputPin,
@@ -82,7 +69,7 @@ where
     }
 
     /// Get the programmed gain of the analog front-end.
-    pub fn get_gain(&self) -> Result<Gain, ()> {
+    pub fn get_gain(&self) -> Gain {
         let mut code: u8 = 0;
         if self.a0.is_set_high().unwrap() {
             code |= 0b1;
@@ -91,6 +78,7 @@ where
             code |= 0b10;
         }
 
-        Gain::try_from(code)
+        // NOTE(unwrap): All possibilities covered.
+        Gain::try_from(code).unwrap()
     }
 }