diff --git a/.github/workflows/hitl.yml b/.github/workflows/hitl.yml
index f59e8d2..b8611d4 100644
--- a/.github/workflows/hitl.yml
+++ b/.github/workflows/hitl.yml
@@ -1,9 +1,9 @@
 name: HITL
 
 on:
-  push:
-    branches: [ hitl ]
   workflow_dispatch:
+  pull_request:
+    branches: [ master ]
 
 jobs:
   hitl:
diff --git a/Cargo.lock b/Cargo.lock
index d203a3c..3aa8999 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "ad9959"
 version = "0.1.0"
@@ -36,7 +38,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9a69a963b70ddacfcd382524f72a4576f359af9334b3bf48a79566590bb8bfa"
 dependencies = [
  "bitrate",
- "cortex-m 0.7.1",
+ "cortex-m 0.7.2",
  "embedded-hal",
 ]
 
@@ -87,9 +89,9 @@ checksum = "c147d86912d04bef727828fda769a76ca81629a46d8ba311a8d58a26aa91473d"
 
 [[package]]
 name = "byteorder"
-version = "1.4.2"
+version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae44d1a3d5a19df61dd0c8beb138458ac2a53a7ac09eba97d55592540004306b"
+checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
 [[package]]
 name = "cast"
@@ -115,15 +117,15 @@ dependencies = [
  "aligned",
  "bare-metal 0.2.5",
  "bitfield",
- "cortex-m 0.7.1",
+ "cortex-m 0.7.2",
  "volatile-register",
 ]
 
 [[package]]
 name = "cortex-m"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0b756a8bffc56025de45218a48ff9b801180440c0ee49a722b32d49dcebc771"
+checksum = "643a210c1bdc23d0db511e2a576082f4ff4dcae9d0c37f50b431b8f8439d6d6b"
 dependencies = [
  "bare-metal 0.2.5",
  "bitfield",
@@ -137,7 +139,7 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0e202d2eac4e34adf7524a563e36623bae6f69cc0a73ef9bd22a4c93a5a806fa"
 dependencies = [
- "cortex-m 0.7.1",
+ "cortex-m 0.7.2",
  "cortex-m-semihosting",
  "log",
 ]
@@ -195,13 +197,13 @@ version = "0.3.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6bffa6c1454368a6aa4811ae60964c38e6996d397ff8095a8b9211b1c1f749bc"
 dependencies = [
- "cortex-m 0.7.1",
+ "cortex-m 0.7.2",
 ]
 
 [[package]]
 name = "derive_miniconf"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/miniconf.git?branch=develop#314fa5587d1aa28e1ad70106f19e30db646e9f28"
+source = "git+https://github.com/quartiq/miniconf.git?rev=314fa5587d#314fa5587d1aa28e1ad70106f19e30db646e9f28"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -359,9 +361,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.6.1"
+version = "1.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fb1fa934250de4de8aef298d81c729a7d33d8c239daa3a7575e6b92bfc7313b"
+checksum = "824845a0bf897a9042383849b02c1bc219c2383772efcd5c6f9766fa4b81aef3"
 dependencies = [
  "autocfg",
  "hashbrown",
@@ -369,9 +371,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.86"
+version = "0.2.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b7282d924be3275cec7f6756ff4121987bc6481325397dde6ba3e7802b1a8b1c"
+checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
 
 [[package]]
 name = "libm"
@@ -390,15 +392,15 @@ dependencies = [
 
 [[package]]
 name = "managed"
-version = "0.8.0"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ca88d725a0a943b096803bd34e73a4437208b6077654cc4ecb2947a5f91618d"
+checksum = "c75de51135344a4f8ed3cfe2720dc27736f7711989703a0b43aadf3753c55577"
 
 [[package]]
 name = "matrixmultiply"
-version = "0.2.4"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "916806ba0031cd542105d916a97c8572e1fa6dd79c9c51e7eb43a09ec2dd84c1"
+checksum = "1300bdbea33ec2836b01ff1f5a6eed8bad66d0c31f94d9b7993407a8b054c3a1"
 dependencies = [
  "rawpointer",
 ]
@@ -406,7 +408,7 @@ dependencies = [
 [[package]]
 name = "mcp23017"
 version = "0.1.1"
-source = "git+https://github.com/mrd0ll4r/mcp23017.git#61933f857abe5a837800493a5f58e91a3c9435ec"
+source = "git+https://github.com/mrd0ll4r/mcp23017.git?rev=61933f857a#61933f857abe5a837800493a5f58e91a3c9435ec"
 dependencies = [
  "embedded-hal",
 ]
@@ -414,7 +416,7 @@ dependencies = [
 [[package]]
 name = "miniconf"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/miniconf.git?branch=develop#314fa5587d1aa28e1ad70106f19e30db646e9f28"
+source = "git+https://github.com/quartiq/miniconf.git?rev=314fa5587d#314fa5587d1aa28e1ad70106f19e30db646e9f28"
 dependencies = [
  "derive_miniconf",
  "heapless 0.6.1",
@@ -426,7 +428,7 @@ dependencies = [
 [[package]]
 name = "minimq"
 version = "0.2.0"
-source = "git+https://github.com/quartiq/minimq.git#933687c2e4bc8a4d972de9a4d1508b0b554a8b38"
+source = "git+https://github.com/quartiq/minimq.git?rev=933687c2e4b#933687c2e4bc8a4d972de9a4d1508b0b554a8b38"
 dependencies = [
  "bit_field",
  "embedded-nal",
@@ -452,9 +454,9 @@ checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
 
 [[package]]
 name = "ndarray"
-version = "0.14.0"
+version = "0.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c0d5c9540a691d153064dc47a4db2504587a75eae07bf1d73f7a596ebc73c04"
+checksum = "cc1372704f14bb132a49a6701c2238970a359ee0829fed481b522a63bf25456a"
 dependencies = [
  "matrixmultiply",
  "num-complex",
@@ -471,9 +473,9 @@ checksum = "2178127478ae4ee9be7180bc9c3bffb6354dd7238400db567102f98c413a9f35"
 
 [[package]]
 name = "num"
-version = "0.3.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b7a8e9be5e039e2ff869df49155f1c06bd01ade2117ec783e56ab0932b67a8f"
+checksum = "43db66d1170d347f9a065114077f7dccb00c1b9478c89384490a3425279a4606"
 dependencies = [
  "num-complex",
  "num-integer",
@@ -484,9 +486,9 @@ dependencies = [
 
 [[package]]
 name = "num-complex"
-version = "0.3.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "747d632c0c558b87dbabbe6a82f3b4ae03720d0646ac5b7b4dae89394be5f2c5"
+checksum = "26873667bbbb7c5182d4a37c1add32cdf09f841af72da53318fdb81543c15085"
 dependencies = [
  "num-traits",
 ]
@@ -514,9 +516,9 @@ dependencies = [
 
 [[package]]
 name = "num-rational"
-version = "0.3.2"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12ac428b1cb17fce6f731001d307d351ec70a6d202fc2e60f7d4c5e42d8f4f07"
+checksum = "d41702bd167c2df5520b384281bc111a4b5efcf7fbc4c9c222c815b07e0a6a6a"
 dependencies = [
  "autocfg",
  "num-integer",
@@ -538,7 +540,7 @@ version = "0.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3d55dedd501dfd02514646e0af4d7016ce36bc12ae177ef52056989966a1eec"
 dependencies = [
- "cortex-m 0.7.1",
+ "cortex-m 0.7.2",
  "cortex-m-semihosting",
 ]
 
@@ -556,9 +558,9 @@ checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.24"
+version = "1.0.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
+checksum = "a152013215dca273577e18d2bf00fa862b89b24169fb78c4c95aeb07992c9cec"
 dependencies = [
  "unicode-xid",
 ]
@@ -667,9 +669,9 @@ checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 
 [[package]]
 name = "serde"
-version = "1.0.124"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bd761ff957cb2a45fbb9ab3da6512de9de55872866160b23c25f1a841e99d29f"
+checksum = "558dc50e1a5a5fa7112ca2ce4effcb321b0300c0d4ccf0776a9f60cd89031171"
 dependencies = [
  "serde_derive",
 ]
@@ -677,7 +679,7 @@ dependencies = [
 [[package]]
 name = "serde-json-core"
 version = "0.2.0"
-source = "git+https://github.com/rust-embedded-community/serde-json-core.git?branch=master#ee06ac91bc43b72450a92198a00d9e5c5b9946d2"
+source = "git+https://github.com/rust-embedded-community/serde-json-core.git?rev=ee06ac91bc#ee06ac91bc43b72450a92198a00d9e5c5b9946d2"
 dependencies = [
  "heapless 0.5.6",
  "serde",
@@ -685,9 +687,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.124"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1800f7693e94e186f5e25a28291ae1570da908aff7d97a095dec1e56ff99069b"
+checksum = "b093b7a2bb58203b5da3056c05b4ec1fed827dcfdb37347a8841695263b3d06d"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -696,8 +698,9 @@ dependencies = [
 
 [[package]]
 name = "smoltcp"
-version = "0.7.0"
-source = "git+https://github.com/smoltcp-rs/smoltcp.git#1bff999a6f3f7adf623d837ea96cc807e1b3a470"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97173c1ef35b0a09304cb3882eba594761243005847cbbf6124f966e8da6519a"
 dependencies = [
  "bitflags",
  "byteorder",
@@ -748,24 +751,25 @@ checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 
 [[package]]
 name = "stm32h7"
-version = "0.12.1"
+version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7571f17d1ed7d67957d0004de6c52bd1ef5e736ed5ddc2bcecf001512269f77c"
+checksum = "8b672c837e0ee8158ecc7fce0f9a948dd0693a9c588338e728d14b73307a0b7d"
 dependencies = [
  "bare-metal 0.2.5",
- "cortex-m 0.6.7",
+ "cortex-m 0.7.2",
  "cortex-m-rt",
  "vcell",
 ]
 
 [[package]]
 name = "stm32h7xx-hal"
-version = "0.8.0"
-source = "git+https://github.com/stm32-rs/stm32h7xx-hal?branch=master#08231e334a11236fe556668ac19cb1c214da2406"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67034b80041bc33a48df1c1c435b6ae3bb18c35e42aa7e702ce8363b96793398"
 dependencies = [
  "bare-metal 1.0.0",
  "cast",
- "cortex-m 0.6.7",
+ "cortex-m 0.7.2",
  "cortex-m-rt",
  "embedded-dma",
  "embedded-hal",
@@ -778,9 +782,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.60"
+version = "1.0.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c700597eca8a5a762beb35753ef6b94df201c81cca676604f547495a0d7f0081"
+checksum = "3ce15dd3ed8aa2f8eeac4716d6ef5ab58b6b9256db41d7e1a0224c2788e8fd87"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -789,9 +793,9 @@ dependencies = [
 
 [[package]]
 name = "typenum"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "373c8a200f9e67a0c95e62a4f52fbf80c23b4381c05a17845531982fa99e6b33"
+checksum = "879f6906492a7cd215bfa4cf595b600146ccfac0c79bcbd1f3000162af5e8b06"
 
 [[package]]
 name = "unicode-xid"
@@ -807,9 +811,9 @@ checksum = "77439c1b53d2303b20d9459b1ade71a83c716e3f9c34f3228c00e6f185d6c002"
 
 [[package]]
 name = "version_check"
-version = "0.9.2"
+version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5a972e5669d67ba988ce3dc826706fb0a8b01471c088cb0b6110b805cc36aed"
+checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
 
 [[package]]
 name = "void"
@@ -831,3 +835,8 @@ name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
+
+[[patch.unused]]
+name = "smoltcp"
+version = "0.7.0"
+source = "git+https://github.com/smoltcp-rs/smoltcp.git#09f941851ded868b759e7db067abd67f2fe136a6"
diff --git a/Cargo.toml b/Cargo.toml
index fe610d5..144444f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -43,35 +43,35 @@ enum-iterator = "0.6.0"
 paste = "1"
 dsp = { path = "dsp" }
 ad9959 = { path = "ad9959" }
-smoltcp-nal = "0.1.0"
-miniconf = "0.1"
 generic-array = "0.14"
+miniconf = "0.1.0"
+
+[dependencies.mcp23017]
+git = "https://github.com/mrd0ll4r/mcp23017.git"
+rev = "61933f857a"
+
+[dependencies.stm32h7xx-hal]
+features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
+version = "0.9.0"
 
 [patch.crates-io.miniconf]
 git = "https://github.com/quartiq/miniconf.git"
-branch = "develop"
+rev = "314fa5587d"
 
-[patch.crates-io.minimq]
-git = "https://github.com/quartiq/minimq.git"
-
-[patch.crates-io.smoltcp-nal]
+[dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
 branch = "feature/reset-support"
 
-[patch.crates-io.serde-json-core]
-git = "https://github.com/rust-embedded-community/serde-json-core.git"
-branch = "master"
+[patch.crates-io.minimq]
+git = "https://github.com/quartiq/minimq.git"
+rev = "933687c2e4b"
 
 [patch.crates-io.smoltcp]
 git = "https://github.com/smoltcp-rs/smoltcp.git"
 
-[dependencies.mcp23017]
-git = "https://github.com/mrd0ll4r/mcp23017.git"
-
-[dependencies.stm32h7xx-hal]
-features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
-git = "https://github.com/stm32-rs/stm32h7xx-hal"
-branch = "master"
+[patch.crates-io.serde-json-core]
+git = "https://github.com/rust-embedded-community/serde-json-core.git"
+rev = "ee06ac91bc"
 
 [features]
 semihosting = ["panic-semihosting", "cortex-m-log/semihosting"]
diff --git a/README.md b/README.md
index 19b5a0d..4250d6a 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 [![QUARTIQ Matrix Chat](https://img.shields.io/matrix/quartiq:matrix.org)](https://matrix.to/#/#quartiq:matrix.org)
+[![Continuous Integration](https://github.com/quartiq/stabilizer/actions/workflows/ci.yml/badge.svg)](https://github.com/quartiq/stabilizer/actions/workflows/ci.yml)
 [![HITL (private)](https://github.com/quartiq/hitl/workflows/Stabilizer/badge.svg)](https://github.com/quartiq/hitl/actions?query=workflow%3AStabilizer)
 
 # Stabilizer Firmware
diff --git a/cargosha256-dual-iir.nix b/cargosha256-dual-iir.nix
index d58968f..2d89c3a 100644
--- a/cargosha256-dual-iir.nix
+++ b/cargosha256-dual-iir.nix
@@ -1 +1 @@
-"138kpxzxs73zhmd4xi5kw3fddb05gac4mpngizm01831n1ycyhl0"
+"06qsl59bljr637xcrplbij7ma8l7waryi4lkbd4fxjac0gqpn55s"
diff --git a/dsp/Cargo.toml b/dsp/Cargo.toml
index 4c675ff..7b680d3 100644
--- a/dsp/Cargo.toml
+++ b/dsp/Cargo.toml
@@ -8,13 +8,13 @@ edition = "2018"
 libm = "0.2.1"
 serde = { version = "1.0", features = ["derive"], default-features = false }
 generic-array = "0.14"
-num = { version = "0.3.1", default-features = false }
+num = { version = "0.4.0", default-features = false }
 miniconf = "0.1"
 
 [dev-dependencies]
 easybench = "1.0"
 rand = "0.8"
-ndarray = "0.14"
+ndarray = "0.15"
 
 [[bench]]
 name = "micro"
diff --git a/hitl/README.md b/hitl/README.md
new file mode 100644
index 0000000..629b587
--- /dev/null
+++ b/hitl/README.md
@@ -0,0 +1,25 @@
+# Stabilizer HITL Testing
+
+This directory contains tooling required for Stabilizer hardware-in-the-loop (HITL) testing.
+
+There is a `Stabilizer` board connected at the Quartiq office that is accessible via a private HITL
+repository in order to provide secure hardware testing of the stabilizer application in a public
+repository.
+
+**Note**: In order to ensure application security, all HITL runs must first be approved by a Quartiq
+representative before execution.
+
+# Configuration
+* Stabilizer is configured with an ethernet connection to a router. The router runs a DHCP server for
+the local network, and ensures that the Stabilizer used for these tests is available under the hostname `stabilizer-hitl`.
+* An MQTT broker is running at the hostname `mqtt`.
+
+# HITL Workflow
+The private HITL repository does the following:
+
+1. Check out this repository
+2. Build firmware images using Cargo
+3. Program stabilizer
+4. Execute `hitl/run.sh`
+
+In order to add new HITL tests, update `run.sh` to include the necessary tests.
diff --git a/hitl/run.sh b/hitl/run.sh
new file mode 100755
index 0000000..a01a472
--- /dev/null
+++ b/hitl/run.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# Title:
+#   Stabilizer hardware-in-the-loop (HITL) test script.
+#
+# Description:
+#   This shell file is executed by the hardware runner in Quartiq's office to exercise the various
+#   hardware aspects of Stabilizer.
+
+# Enable shell operating mode flags.
+set -eux
+
+# Set up python for testing
+python3 -m venv --system-site-packages py
+. py/bin/activate
+python3 -m pip install -r requirements.txt
+
+# Test pinging Stabilizer. This exercises that:
+# * DHCP is functional and an IP has been acquired
+# * Stabilizer's network is functioning as intended
+# * The stabilizer application is operational
+ping -c 5 -w 20 stabilizer-hitl
+
+# Test the MQTT interface.
+python3 miniconf.py dt/sinara/stabilizer afe/0 '"G2"'
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..a3d7fef
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+gmqtt
diff --git a/src/hardware/pounder/mod.rs b/src/hardware/pounder/mod.rs
index 0497a37..32a8e80 100644
--- a/src/hardware/pounder/mod.rs
+++ b/src/hardware/pounder/mod.rs
@@ -231,14 +231,16 @@ impl ad9959::Interface for QspiInterface {
                 };
 
                 self.qspi
-                    .write(encoded_address, &encoded_payload)
+                    .write(encoded_address.into(), &encoded_payload)
                     .map_err(|_| Error::Qspi)
             }
             ad9959::Mode::FourBitSerial => {
                 if self.streaming {
                     Err(Error::Qspi)
                 } else {
-                    self.qspi.write(addr, data).map_err(|_| Error::Qspi)?;
+                    self.qspi
+                        .write(addr.into(), data)
+                        .map_err(|_| Error::Qspi)?;
                     Ok(())
                 }
             }
@@ -257,7 +259,7 @@ impl ad9959::Interface for QspiInterface {
         }
 
         self.qspi
-            .read(0x80_u8 | addr, dest)
+            .read((0x80_u8 | addr).into(), dest)
             .map_err(|_| Error::Qspi)
     }
 }