fix: implement sign-magnitude encoding for signed registers

.github/workflows/ci.yml

@@ -12,221 +12,16 @@ on:
     branches: [main]
 
 permissions:
-  contents: read
+  contents: write
+  security-events: write
+  pages: write
+  id-token: write
 
 jobs:
-  build-test:
-    name: MIX_ENV=test mix compile
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/install-elixir@59199173e18eee6748b65d01626ef82d51c6e963 # main
-      - name: Set OS deps compile partition count
-        run: echo "MIX_OS_DEPS_COMPILE_PARTITION_COUNT=$(($(lscpu -p | grep -v '^#' | sort -u -t, -k 2,4 | wc -l) / 2))" >> $GITHUB_ENV
-      - uses: team-alembic/staple-actions/actions/mix-compile@04f27881d51ef973841fc40c549aefb7b52db7f7 # main
-        with:
-          mix-env: test
-          args: "--warnings-as-errors"
-
-  test:
-    name: mix test
-    runs-on: ubuntu-latest
-    needs: build-test
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-test@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: test
-
-  credo:
-    name: mix credo --strict
-    runs-on: ubuntu-latest
-    needs: build-test
-    permissions:
-      security-events: write
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-credo@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: test
-      - name: Run Credo SAST
-        uses: team-alembic/staple-actions/actions/mix-task@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          task: credo --format sarif > results.sarif
-      - name: Upload SARIF file
-        uses: github/codeql-action/upload-sarif@cdefb33c0f6224e58673d9004f47f7cb3e328b89 # v4.31.10
-        with:
-          sarif_file: results.sarif
-          category: credo
-
-  formatter:
-    name: mix format --check-formatted
-    runs-on: ubuntu-latest
-    needs: build-test
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-format@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: test
-
-  dialyzer:
-    name: mix dialyzer
-    runs-on: ubuntu-latest
-    needs: build-test
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-dialyzer@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: dev
-
-  audit:
-    name: mix deps.audit + hex.audit
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-hex-audit@59199173e18eee6748b65d01626ef82d51c6e963 # main
-      - uses: team-alembic/staple-actions/actions/mix-task@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          task: deps.audit
-
-  unused-deps:
-    name: mix deps.unlock --check-unused
-    runs-on: ubuntu-latest
-    needs: build-test
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-task@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: test
-          task: deps.unlock --check-unused
-
-  reuse:
-    name: REUSE compliance
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - name: REUSE compliance check
-        uses: fsfe/reuse-action@v6
-
-  build-docs:
-    name: mix docs
-    runs-on: ubuntu-latest
-    needs:
-      - build-test
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: team-alembic/staple-actions/actions/mix-docs@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: dev
-          use-cache: false
-      - uses: actions/upload-pages-artifact@7b1f4a764d45c48632c6b24a0339c27f5614fb0b # v4.0.0
-        with:
-          path: doc/
-
-  deploy-docs:
-    name: Deploy docs to GitHub Pages
-    runs-on: ubuntu-latest
-    needs: build-docs
-    if: github.ref == 'refs/heads/main'
-    permissions:
-      pages: write
-      id-token: write
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@d6db90164ac5ed86f2b6aed7e0febac5b3c0c03e # v4.0.5
-
-  release:
-    name: Publish to Hex.pm
-    runs-on: ubuntu-latest
-    needs:
-      - test
-      - dialyzer
-      - credo
-      - formatter
-      - audit
-      - unused-deps
-      - reuse
-    if: startsWith(github.ref, 'refs/tags/v')
-    permissions:
-      contents: write
-    steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - name: Extract release notes from CHANGELOG.md
-        id: extract-notes
-        run: |
-          TAG_NAME=${GITHUB_REF#refs/tags/}
-          VERSION=${TAG_NAME#v}
-
-          # Extract the section for this version from CHANGELOG.md
-          awk -v version="$VERSION" '
-            /^## \[v?[0-9]/ {
-              if (found) exit
-              if (index($0, "[v" version "]") || index($0, "[" version "]")) {
-                found = 1
-                next
-              }
-            }
-            found {
-              if (/^## \[v?[0-9]/) exit
-              print
-            }
-          ' CHANGELOG.md > release_notes.md
-
-          # Check if notes were found
-          if [ -s release_notes.md ]; then
-            echo "has_notes=true" >> $GITHUB_OUTPUT
-            echo "Release notes extracted for version $VERSION"
-          else
-            echo "has_notes=false" >> $GITHUB_OUTPUT
-            echo "No release notes found for version $VERSION, will use auto-generated notes"
-          fi
-      - name: Create prerelease with changelog notes
-        if: ${{ (contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') || contains(github.ref, '-pre')) && steps.extract-notes.outputs.has_notes == 'true' }}
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-        run: |
-          gh release create \
-            --repo ${{ github.repository }} \
-            --title ${GITHUB_REF#refs/tags/} \
-            --prerelease \
-            --notes-file release_notes.md \
-            ${GITHUB_REF#refs/tags/}
-      - name: Create prerelease with generated notes
-        if: ${{ (contains(github.ref, '-rc') || contains(github.ref, '-beta') || contains(github.ref, '-alpha') || contains(github.ref, '-pre')) && steps.extract-notes.outputs.has_notes != 'true' }}
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-        run: |
-          gh release create \
-            --repo ${{ github.repository }} \
-            --title ${GITHUB_REF#refs/tags/} \
-            --prerelease \
-            --generate-notes \
-            ${GITHUB_REF#refs/tags/}
-      - name: Create release with changelog notes
-        if: ${{ (!contains(github.ref, '-rc') && !contains(github.ref, '-beta') && !contains(github.ref, '-alpha') && !contains(github.ref, '-pre')) && steps.extract-notes.outputs.has_notes == 'true' }}
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-        run: |
-          gh release create \
-            --repo ${{ github.repository }} \
-            --title ${GITHUB_REF#refs/tags/} \
-            --notes-file release_notes.md \
-            ${GITHUB_REF#refs/tags/}
-      - name: Create release with generated notes
-        if: ${{ (!contains(github.ref, '-rc') && !contains(github.ref, '-beta') && !contains(github.ref, '-alpha') && !contains(github.ref, '-pre')) && steps.extract-notes.outputs.has_notes != 'true' }}
-        env:
-          GITHUB_TOKEN: ${{ github.token }}
-        run: |
-          gh release create \
-            --repo ${{ github.repository }} \
-            --title ${GITHUB_REF#refs/tags/} \
-            --generate-notes \
-            ${GITHUB_REF#refs/tags/}
-      - uses: team-alembic/staple-actions/actions/mix-hex-publish@59199173e18eee6748b65d01626ef82d51c6e963 # main
-        with:
-          mix-env: dev
-          hex-api-key: ${{ secrets.HEX_API_KEY }}
+  CI:
+    uses: beam-bots/.github/.github/workflows/elixir-ci.yml@61ed48adfb0acec3baa9a32114d377546ee70478 # main
+    with:
+      enable-docs-deploy: true
+      enable-release: true
+    secrets:
+      HEX_API_KEY: ${{ secrets.HEX_API_KEY }}

lib/feetech/control_table.ex

@@ -35,12 +35,14 @@ defmodule Feetech.ControlTable do
     * `nil` - No conversion, raw integer value
     * `:bool` - 0/1 to false/true
     * `float` - Scale factor (e.g., `0.1` for voltage in 0.1V units)
-    * `:position` - Steps to radians (servo-specific)
+    * `:position` - Steps to radians (unsigned, servo-specific)
+    * `:position_signed` - Steps to radians with sign-magnitude encoding (bit 15 = sign)
     * `:speed` - Speed units to rad/s
-    * `:speed_signed` - Signed speed to rad/s
-    * `:load_signed` - Signed load percentage
+    * `:speed_signed` - Signed speed to rad/s (sign-magnitude, bit 15 = sign)
+    * `:load_signed` - Signed load percentage (sign-magnitude, bit 10 = sign)
     * `:mode` - Operating mode enum
     * `:baud_rate` - Baud rate enum
+    * `{:sign_magnitude, sign_bit}` - Raw sign-magnitude with specified sign bit
     * `{module, decode_fun, encode_fun}` - Custom conversion functions
   """
 
@@ -62,12 +64,14 @@ defmodule Feetech.ControlTable do
           nil
           | :bool
           | :position
+          | :position_signed
           | :speed
           | :speed_signed
           | :load_signed
           | :mode
           | :baud_rate
           | float()
+          | {:sign_magnitude, non_neg_integer()}
           | {module(), atom(), atom()}
 
   @typedoc "Register definition tuple"
@@ -147,19 +151,28 @@ defmodule Feetech.ControlTable do
     Protocol.encode_int(steps, length)
   end
 
+  defp encode_value(value, length, :position_signed, table) do
+    steps = round(value / table.position_scale())
+    Protocol.encode_sign_magnitude(steps, 15, length)
+  end
+
   defp encode_value(value, length, :speed, table) do
     raw = round(value / table.speed_scale())
     Protocol.encode_int(raw, length)
   end
 
   defp encode_value(value, length, :speed_signed, table) do
     raw = round(value / table.speed_scale())
-    Protocol.encode_int(raw, length)
+    Protocol.encode_sign_magnitude(raw, 15, length)
   end
 
   defp encode_value(value, length, :load_signed, _table) do
     raw = round(value * 10)
-    Protocol.encode_int(raw, length)
+    Protocol.encode_sign_magnitude(raw, 10, length)
+  end
+
+  defp encode_value(value, length, {:sign_magnitude, sign_bit}, _table) do
+    Protocol.encode_sign_magnitude(value, sign_bit, length)
   end
 
   defp encode_value(value, length, :mode, table) do
@@ -193,16 +206,24 @@ defmodule Feetech.ControlTable do
     Protocol.decode_int(data) * table.position_scale()
   end
 
+  defp decode_value(data, :position_signed, table) do
+    Protocol.decode_sign_magnitude(data, 15) * table.position_scale()
+  end
+
   defp decode_value(data, :speed, table) do
     Protocol.decode_int(data) * table.speed_scale()
   end
 
   defp decode_value(data, :speed_signed, table) do
-    Protocol.decode_int_signed(data) * table.speed_scale()
+    Protocol.decode_sign_magnitude(data, 15) * table.speed_scale()
   end
 
   defp decode_value(data, :load_signed, _table) do
-    Protocol.decode_int_signed(data) * 0.1
+    Protocol.decode_sign_magnitude(data, 10) * 0.1
+  end
+
+  defp decode_value(data, {:sign_magnitude, sign_bit}, _table) do
+    Protocol.decode_sign_magnitude(data, sign_bit)
   end
 
   defp decode_value(data, :mode, table) do

lib/feetech/control_table/sts3215.ex

@@ -80,7 +80,7 @@ defmodule Feetech.ControlTable.STS3215 do
       ccw_dead_band: {27, 1, nil},
       overload_current: {28, 2, nil},
       angular_resolution: {30, 1, nil},
-      position_offset: {31, 2, nil},
+      position_offset: {31, 2, {:sign_magnitude, 11}},
       mode: {33, 1, :mode},
       protection_torque: {34, 1, nil},
       protection_time: {35, 1, nil},
@@ -89,14 +89,14 @@ defmodule Feetech.ControlTable.STS3215 do
       # SRAM - volatile settings (address 40-54)
       torque_enable: {40, 1, :bool},
       acceleration: {41, 1, nil},
-      goal_position: {42, 2, :position},
+      goal_position: {42, 2, :position_signed},
       goal_time: {44, 2, nil},
       goal_speed: {46, 2, :speed},
       torque_limit: {48, 2, 0.001},
       lock: {55, 1, :bool},
 
       # SRAM - read-only feedback (address 56+)
-      present_position: {56, 2, :position},
+      present_position: {56, 2, :position_signed},
       present_speed: {58, 2, :speed_signed},
       present_load: {60, 2, :load_signed},
       present_voltage: {62, 1, 0.1},