From 2e3768b4b2f9ab6b0a355ffd3d68a4d115e205a0 Mon Sep 17 00:00:00 2001
From: Mendel Mobach <mendel@mobach.nl>
Date: Fri, 16 Oct 2026 18:41:33 +0200
Subject: [PATCH 1/5] Isolate Chromium profiles in browser smoke tests

---
 tests/js/browser-smoke.test.js | 36 ++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/tests/js/browser-smoke.test.js b/tests/js/browser-smoke.test.js
index bc24b04..81318da 100644
--- a/tests/js/browser-smoke.test.js
+++ b/tests/js/browser-smoke.test.js
@@ -20,19 +20,27 @@ function chromiumCommand() {
 }
 
 function runChromium(command, url) {
-  return spawnSync(command, [
-    "--headless",
-    "--disable-gpu",
-    "--disable-dev-shm-usage",
-    "--no-sandbox",
-    "--allow-file-access-from-files",
-    "--dump-dom",
-    "--virtual-time-budget=3000",
-    url,
-  ], {
-    encoding: "utf8",
-    timeout: 20000,
-  });
+  const profile = fs.mkdtempSync(path.join(os.tmpdir(), "kassa-chromium-"));
+  try {
+    return spawnSync(command, [
+      `--user-data-dir=${profile}`,
+      "--no-first-run",
+      "--no-default-browser-check",
+      "--headless",
+      "--disable-gpu",
+      "--disable-dev-shm-usage",
+      "--no-sandbox",
+      "--allow-file-access-from-files",
+      "--dump-dom",
+      "--virtual-time-budget=3000",
+      url,
+    ], {
+      encoding: "utf8",
+      timeout: 40000,
+    });
+  } finally {
+    fs.rmSync(profile, {recursive: true, force: true});
+  }
 }
 
 function skipIfChromiumSandboxed(t, result) {
@@ -103,6 +111,7 @@ test("kassa index boots in a real browser", (t) => {
   fs.unlinkSync(fixturePath);
   if(skipIfChromiumSandboxed(t, result)) return;
 
+  assert.ifError(result.error);
   assert.equal(result.status, 0, result.stderr);
   const match = result.stdout.match(/<pre id="smoke-result">([^<]+)<\/pre>/);
   assert(match, result.stdout);
@@ -148,6 +157,7 @@ test("kassa frontend posts keyboard and button input in a browser", (t) => {
   fs.unlinkSync(fixturePath);
   if(skipIfChromiumSandboxed(t, result)) return;
 
+  assert.ifError(result.error);
   assert.equal(result.status, 0, result.stderr);
   const match = result.stdout.match(/<pre id="smoke-result">([^<]+)<\/pre>/);
   assert(match, result.stdout);

From ad5f65ecc0dfc711c5c3a8b6730edc225db53449 Mon Sep 17 00:00:00 2001
From: Mendel Mobach <mendel@mobach.nl>
Date: Fri, 16 Oct 2026 18:45:39 +0200
Subject: [PATCH 2/5] Print configurable Epson receipt header images

---
 README.md                 | 23 +++++++++++++++
 config.py                 |  4 +++
 config.yaml.example       |  5 ++++
 plugins/POS.py            | 42 +++++++++++++++++++++++++---
 tests/plugins/test_POS.py | 59 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 129 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 9b6f4ce..a702e01 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,29 @@ You need python, paho-mqtt-client and apache+php.
 
 To install the python dependencies, run 'pip install -r requirements.txt'.
 
+### Receipt header image
+
+The Epson receipt header defaults to `images/hack42.png`. Configure another
+PNG/JPEG file and maximum width in printer dots in `config.yaml`:
+
+```yaml
+pos:
+  header:
+    image: images/hack42.png
+    width: 384
+```
+
+Relative image paths resolve from the project directory. Transparent pixels
+print white; the image is scaled down proportionally and converted to monochrome.
+The header is sent with each new receipt, stock overview, declaration, and party
+settlement. Existing saved receipts retain their original header when reprinted.
+Set `image: ""` to keep using the logo stored in the printer. If the configured
+file cannot be loaded, a warning is logged and the stored logo is used.
+
+This uses Epson's [GS v 0 raster command](https://download4.epson.biz/sec_pubs/pos/reference_en/escpos/gs_lv_0.html),
+which must be supported by the printer model. It does not change the printer's
+nonvolatile logo memory. Set `width` to at most your printer's printable width.
+
 ### data
 
 Data is stored in 'data'. In production it is also committed to git, but for
diff --git a/config.py b/config.py
index 8cb4909..83eb2fc 100644
--- a/config.py
+++ b/config.py
@@ -28,6 +28,10 @@
         },
     },
     "pos": {
+        "header": {
+            "image": "images/hack42.png",
+            "width": 384,
+        },
         "serial": {
             "port": "/dev/ttyUSB0",
             "baudrate": 19200,
diff --git a/config.yaml.example b/config.yaml.example
index 4be949e..423c1a6 100644
--- a/config.yaml.example
+++ b/config.yaml.example
@@ -22,6 +22,11 @@ stickers:
     # identifier: tcp://BRW008092D4A414.space.hack42.nl:9100
 
 pos:
+  header:
+    # Relative to the project directory, or an absolute path.
+    # Set image to "" to use the logo already stored in the printer.
+    image: images/hack42.png
+    width: 384
   serial:
     port: /dev/ttyUSB0
     baudrate: 19200
diff --git a/plugins/POS.py b/plugins/POS.py
index c9920a4..e503385 100644
--- a/plugins/POS.py
+++ b/plugins/POS.py
@@ -4,9 +4,12 @@
 import json
 import logging
 import pickle
+from pathlib import Path
+import struct
 import time
 
 import serial
+from PIL import Image, ImageOps
 
 from config import config_get
 
@@ -67,8 +70,39 @@ def help(self):
             "printstock": "Print stock overview",
         }
 
+    def header_image(self):
+        settings = config_get("pos", "header", default={})
+        filename = settings.get("image", "")
+        if not filename:
+            return LOGO
+        try:
+            width = int(settings.get("width", 384))
+            if not 8 <= width <= 2048:
+                raise ValueError("Header width must be between 8 and 2048 dots")
+            path = Path(filename)
+            if not path.is_absolute():
+                path = Path(__file__).resolve().parent.parent / path
+            with Image.open(path) as source:
+                rgba = source.convert("RGBA")
+            rgba.thumbnail((width, 2048), Image.Resampling.LANCZOS)
+            white = Image.new("RGBA", rgba.size, "white")
+            gray = Image.alpha_composite(white, rgba).convert("L")
+            # Epson raster bits use 1 for ink; Pillow uses 1 for white.
+            ink = ImageOps.invert(gray.point(lambda value: 255 if value >= 128 else 0))
+            row_bytes = (ink.width + 7) // 8
+            padded = Image.new("1", (row_bytes * 8, ink.height), 0)
+            padded.paste(ink.convert("1"), (0, 0))
+            return (
+                b"\x1dv0\x00"
+                + struct.pack("<HH", row_bytes, ink.height)
+                + padded.tobytes()
+            )
+        except (OSError, TypeError, ValueError) as exc:
+            logger.warning("pos_header_image_failed sid=%s error=%s", self.SID, exc)
+            return LOGO
+
     def printstock(self):
-        BON = PRINTER + LARGE + CENTER + LOGO + NORMAL + LEFT
+        BON = PRINTER + LARGE + CENTER + self.header_image() + NORMAL + LEFT
         for name in sorted(self.master.stock.stock.keys()):
             num = self.master.stock.stock[name]
             BON += b"%20s %5d\n" % (name.encode(), num)
@@ -118,7 +152,7 @@ def projected_balance(self, user):
         return balance_before_checkout + self.master.receipt.totals[user]
 
     def makebon(self, user):
-        BON = PRINTER + LARGE + CENTER + LOGO
+        BON = PRINTER + LARGE + CENTER + self.header_image()
         is_cash = user == "cash"
         projected_balance = None
         if not is_cash:
@@ -174,7 +208,7 @@ def makebon(self, user):
 
     def printdeclaratie(self, args):
         Name, Type, Reason, Bar, Cash, Bank = args
-        BON = PRINTER + LARGE + CENTER + LOGO
+        BON = PRINTER + LARGE + CENTER + self.header_image()
         BON += (
             NORMAL
             + b"Declaratie\n\n"
@@ -200,7 +234,7 @@ def printdeclaratie(self, args):
         self.slowwrite(BON)
 
     def makepartybon(self, settlement):
-        BON = PRINTER + LARGE + CENTER + LOGO
+        BON = PRINTER + LARGE + CENTER + self.header_image()
         BON += NORMAL + b"Party mode afrekening\n\n"
         BON += RIGHT + b"%s  -  Arnhem\n" % time.strftime("%Y-%m-%d %H:%M:%S").encode()
         BON += LEFT + b"\n"
diff --git a/tests/plugins/test_POS.py b/tests/plugins/test_POS.py
index df376cc..282e37f 100644
--- a/tests/plugins/test_POS.py
+++ b/tests/plugins/test_POS.py
@@ -2,6 +2,10 @@
 import plugins.POS as POS_module
 import json
 import pickle
+import struct
+
+import pytest
+from PIL import Image
 
 
 class TestPOS:
@@ -9,6 +13,61 @@ def setup_method(self, method):
         self.master_mock = Mock()
         self.POS = POS_module.POS("SID", self.master_mock)
 
+    def test_header_image_encodes_ink_transparency_and_row_padding(self, tmp_path):
+        image_path = tmp_path / "header.png"
+        image = Image.new("RGBA", (9, 1), (0, 0, 0, 0))
+        image.putpixel((0, 0), (0, 0, 0, 255))
+        image.putpixel((8, 0), (0, 0, 0, 255))
+        image.save(image_path)
+        with patch("plugins.POS.config_get", return_value={"image": str(image_path)}):
+            output = self.POS.header_image()
+
+        assert output == b"\x1dv0\x00" + struct.pack("<HH", 2, 1) + b"\x80\x80"
+
+    def test_header_image_scales_to_configured_width(self, tmp_path):
+        image_path = tmp_path / "header.png"
+        Image.new("RGB", (32, 16), "black").save(image_path)
+        with patch(
+            "plugins.POS.config_get",
+            return_value={"image": str(image_path), "width": 16},
+        ):
+            output = self.POS.header_image()
+
+        assert output[:8] == b"\x1dv0\x00" + struct.pack("<HH", 2, 8)
+        assert output[8:] == b"\xff" * 16
+
+    def test_header_image_defaults_to_bundled_logo_outside_project(
+        self, tmp_path, monkeypatch
+    ):
+        monkeypatch.chdir(tmp_path)
+        output = self.POS.header_image()
+
+        assert output.startswith(b"\x1dv0\x00")
+        row_bytes, height = struct.unpack("<HH", output[4:8])
+        assert row_bytes <= 48
+        assert len(output[8:]) == row_bytes * height
+
+    def test_header_image_empty_setting_keeps_printer_logo(self):
+        with patch("plugins.POS.config_get", return_value={"image": ""}):
+            assert self.POS.header_image() == POS_module.LOGO
+
+    @pytest.mark.parametrize("width", [0, 2049, "invalid", None])
+    def test_header_image_invalid_width_falls_back(self, width, caplog):
+        with patch(
+            "plugins.POS.config_get",
+            return_value={"image": "header.png", "width": width},
+        ):
+            assert self.POS.header_image() == POS_module.LOGO
+        assert "pos_header_image_failed" in caplog.text
+
+    def test_header_image_missing_file_falls_back(self, tmp_path, caplog):
+        with patch(
+            "plugins.POS.config_get",
+            return_value={"image": str(tmp_path / "missing.png")},
+        ):
+            assert self.POS.header_image() == POS_module.LOGO
+        assert "pos_header_image_failed" in caplog.text
+
     def test_open(self):
         with patch("plugins.POS.serial", new=Mock()):
             self.POS.open()

From def4236f84fccaa5b074525e00720dad73e8afd5 Mon Sep 17 00:00:00 2001
From: Mendel Mobach <mendel@mobach.nl>
Date: Fri, 16 Oct 2026 18:51:02 +0200
Subject: [PATCH 3/5] Revert "Print configurable Epson receipt header images"

This reverts commit ad5f65ecc0dfc711c5c3a8b6730edc225db53449.
---
 README.md                 | 23 ---------------
 config.py                 |  4 ---
 config.yaml.example       |  5 ----
 plugins/POS.py            | 42 +++-------------------------
 tests/plugins/test_POS.py | 59 ---------------------------------------
 5 files changed, 4 insertions(+), 129 deletions(-)

diff --git a/README.md b/README.md
index 9b4a9d0..fcb17aa 100644
--- a/README.md
+++ b/README.md
@@ -9,29 +9,6 @@ You need python, paho-mqtt-client and apache+php.
 
 To install the python dependencies, run 'pip install -r requirements.txt'.
 
-### Receipt header image
-
-The Epson receipt header defaults to `images/hack42.png`. Configure another
-PNG/JPEG file and maximum width in printer dots in `config.yaml`:
-
-```yaml
-pos:
-  header:
-    image: images/hack42.png
-    width: 384
-```
-
-Relative image paths resolve from the project directory. Transparent pixels
-print white; the image is scaled down proportionally and converted to monochrome.
-The header is sent with each new receipt, stock overview, declaration, and party
-settlement. Existing saved receipts retain their original header when reprinted.
-Set `image: ""` to keep using the logo stored in the printer. If the configured
-file cannot be loaded, a warning is logged and the stored logo is used.
-
-This uses Epson's [GS v 0 raster command](https://download4.epson.biz/sec_pubs/pos/reference_en/escpos/gs_lv_0.html),
-which must be supported by the printer model. It does not change the printer's
-nonvolatile logo memory. Set `width` to at most your printer's printable width.
-
 ### Printer and cash drawer
 
 The POS serial port defaults to `/dev/ttyKASSA`. Install the udev rule on the
diff --git a/config.py b/config.py
index 92210b2..d1ddf43 100644
--- a/config.py
+++ b/config.py
@@ -28,10 +28,6 @@
         },
     },
     "pos": {
-        "header": {
-            "image": "images/hack42.png",
-            "width": 384,
-        },
         "serial": {
             "port": "/dev/ttyKASSA",
             "baudrate": 19200,
diff --git a/config.yaml.example b/config.yaml.example
index 1c48ed0..3601400 100644
--- a/config.yaml.example
+++ b/config.yaml.example
@@ -22,11 +22,6 @@ stickers:
     # identifier: tcp://BRW008092D4A414.space.hack42.nl:9100
 
 pos:
-  header:
-    # Relative to the project directory, or an absolute path.
-    # Set image to "" to use the logo already stored in the printer.
-    image: images/hack42.png
-    width: 384
   serial:
     port: /dev/ttyKASSA
     baudrate: 19200
diff --git a/plugins/POS.py b/plugins/POS.py
index e503385..c9920a4 100644
--- a/plugins/POS.py
+++ b/plugins/POS.py
@@ -4,12 +4,9 @@
 import json
 import logging
 import pickle
-from pathlib import Path
-import struct
 import time
 
 import serial
-from PIL import Image, ImageOps
 
 from config import config_get
 
@@ -70,39 +67,8 @@ def help(self):
             "printstock": "Print stock overview",
         }
 
-    def header_image(self):
-        settings = config_get("pos", "header", default={})
-        filename = settings.get("image", "")
-        if not filename:
-            return LOGO
-        try:
-            width = int(settings.get("width", 384))
-            if not 8 <= width <= 2048:
-                raise ValueError("Header width must be between 8 and 2048 dots")
-            path = Path(filename)
-            if not path.is_absolute():
-                path = Path(__file__).resolve().parent.parent / path
-            with Image.open(path) as source:
-                rgba = source.convert("RGBA")
-            rgba.thumbnail((width, 2048), Image.Resampling.LANCZOS)
-            white = Image.new("RGBA", rgba.size, "white")
-            gray = Image.alpha_composite(white, rgba).convert("L")
-            # Epson raster bits use 1 for ink; Pillow uses 1 for white.
-            ink = ImageOps.invert(gray.point(lambda value: 255 if value >= 128 else 0))
-            row_bytes = (ink.width + 7) // 8
-            padded = Image.new("1", (row_bytes * 8, ink.height), 0)
-            padded.paste(ink.convert("1"), (0, 0))
-            return (
-                b"\x1dv0\x00"
-                + struct.pack("<HH", row_bytes, ink.height)
-                + padded.tobytes()
-            )
-        except (OSError, TypeError, ValueError) as exc:
-            logger.warning("pos_header_image_failed sid=%s error=%s", self.SID, exc)
-            return LOGO
-
     def printstock(self):
-        BON = PRINTER + LARGE + CENTER + self.header_image() + NORMAL + LEFT
+        BON = PRINTER + LARGE + CENTER + LOGO + NORMAL + LEFT
         for name in sorted(self.master.stock.stock.keys()):
             num = self.master.stock.stock[name]
             BON += b"%20s %5d\n" % (name.encode(), num)
@@ -152,7 +118,7 @@ def projected_balance(self, user):
         return balance_before_checkout + self.master.receipt.totals[user]
 
     def makebon(self, user):
-        BON = PRINTER + LARGE + CENTER + self.header_image()
+        BON = PRINTER + LARGE + CENTER + LOGO
         is_cash = user == "cash"
         projected_balance = None
         if not is_cash:
@@ -208,7 +174,7 @@ def makebon(self, user):
 
     def printdeclaratie(self, args):
         Name, Type, Reason, Bar, Cash, Bank = args
-        BON = PRINTER + LARGE + CENTER + self.header_image()
+        BON = PRINTER + LARGE + CENTER + LOGO
         BON += (
             NORMAL
             + b"Declaratie\n\n"
@@ -234,7 +200,7 @@ def printdeclaratie(self, args):
         self.slowwrite(BON)
 
     def makepartybon(self, settlement):
-        BON = PRINTER + LARGE + CENTER + self.header_image()
+        BON = PRINTER + LARGE + CENTER + LOGO
         BON += NORMAL + b"Party mode afrekening\n\n"
         BON += RIGHT + b"%s  -  Arnhem\n" % time.strftime("%Y-%m-%d %H:%M:%S").encode()
         BON += LEFT + b"\n"
diff --git a/tests/plugins/test_POS.py b/tests/plugins/test_POS.py
index 282e37f..df376cc 100644
--- a/tests/plugins/test_POS.py
+++ b/tests/plugins/test_POS.py
@@ -2,10 +2,6 @@
 import plugins.POS as POS_module
 import json
 import pickle
-import struct
-
-import pytest
-from PIL import Image
 
 
 class TestPOS:
@@ -13,61 +9,6 @@ def setup_method(self, method):
         self.master_mock = Mock()
         self.POS = POS_module.POS("SID", self.master_mock)
 
-    def test_header_image_encodes_ink_transparency_and_row_padding(self, tmp_path):
-        image_path = tmp_path / "header.png"
-        image = Image.new("RGBA", (9, 1), (0, 0, 0, 0))
-        image.putpixel((0, 0), (0, 0, 0, 255))
-        image.putpixel((8, 0), (0, 0, 0, 255))
-        image.save(image_path)
-        with patch("plugins.POS.config_get", return_value={"image": str(image_path)}):
-            output = self.POS.header_image()
-
-        assert output == b"\x1dv0\x00" + struct.pack("<HH", 2, 1) + b"\x80\x80"
-
-    def test_header_image_scales_to_configured_width(self, tmp_path):
-        image_path = tmp_path / "header.png"
-        Image.new("RGB", (32, 16), "black").save(image_path)
-        with patch(
-            "plugins.POS.config_get",
-            return_value={"image": str(image_path), "width": 16},
-        ):
-            output = self.POS.header_image()
-
-        assert output[:8] == b"\x1dv0\x00" + struct.pack("<HH", 2, 8)
-        assert output[8:] == b"\xff" * 16
-
-    def test_header_image_defaults_to_bundled_logo_outside_project(
-        self, tmp_path, monkeypatch
-    ):
-        monkeypatch.chdir(tmp_path)
-        output = self.POS.header_image()
-
-        assert output.startswith(b"\x1dv0\x00")
-        row_bytes, height = struct.unpack("<HH", output[4:8])
-        assert row_bytes <= 48
-        assert len(output[8:]) == row_bytes * height
-
-    def test_header_image_empty_setting_keeps_printer_logo(self):
-        with patch("plugins.POS.config_get", return_value={"image": ""}):
-            assert self.POS.header_image() == POS_module.LOGO
-
-    @pytest.mark.parametrize("width", [0, 2049, "invalid", None])
-    def test_header_image_invalid_width_falls_back(self, width, caplog):
-        with patch(
-            "plugins.POS.config_get",
-            return_value={"image": "header.png", "width": width},
-        ):
-            assert self.POS.header_image() == POS_module.LOGO
-        assert "pos_header_image_failed" in caplog.text
-
-    def test_header_image_missing_file_falls_back(self, tmp_path, caplog):
-        with patch(
-            "plugins.POS.config_get",
-            return_value={"image": str(tmp_path / "missing.png")},
-        ):
-            assert self.POS.header_image() == POS_module.LOGO
-        assert "pos_header_image_failed" in caplog.text
-
     def test_open(self):
         with patch("plugins.POS.serial", new=Mock()):
             self.POS.open()

From 64a5bea0fb73f1665c7842fec19194f10f396e2d Mon Sep 17 00:00:00 2001
From: Mendel Mobach <mendel@mobach.nl>
Date: Fri, 16 Oct 2026 18:52:53 +0200
Subject: [PATCH 4/5] Upload Epson logo once to nonvolatile printer memory

---
 Makefile                        |   4 +-
 README.md                       |  29 ++++++++
 load_printer_logo.py            | 105 +++++++++++++++++++++++++++++
 tests/test_load_printer_logo.py | 116 ++++++++++++++++++++++++++++++++
 4 files changed, 252 insertions(+), 2 deletions(-)
 create mode 100644 load_printer_logo.py
 create mode 100644 tests/test_load_printer_logo.py

diff --git a/Makefile b/Makefile
index 92bf406..b4301cd 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 PYTHON ?= python3
 NPM ?= npm
 PHP ?= php
-PY_FILES := kassa.py $(shell find plugins tests -type f -name '*.py' | sort)
+PY_FILES := kassa.py load_printer_logo.py $(shell find plugins tests -type f -name '*.py' | sort)
 PHP_FILES := $(shell find www -type f -name '*.php' | sort)
 
 .PHONY: test python-test js-test php-test venv pip-compile pip-sync pip-sync-dev lint python-lint js-lint php-lint check-types fix check
@@ -42,7 +42,7 @@ pip-sync-dev: ## synchronizes the .venv with the state of requirements.txt
 lint: python-lint js-lint php-lint  ## Do basic linting
 
 python-lint: venv
-	@. .venv/bin/activate && ${env} ${PYTHON} -m pylint --persistent=no kassa.py plugins
+	@. .venv/bin/activate && ${env} ${PYTHON} -m pylint --persistent=no kassa.py load_printer_logo.py plugins
 	@. .venv/bin/activate; for file in ${PY_FILES}; do ${env} ${PYTHON} -m black --check --quiet --workers 1 "$$file" || exit $$?; done
 
 node_modules/.package-lock.json: package.json package-lock.json
diff --git a/README.md b/README.md
index fcb17aa..8636feb 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,35 @@ remain supported. The adapter has no unique serial number, so this rule assumes
 only one `067b:2303` adapter is connected. With several identical adapters, narrow
 the rule to the appropriate USB port before installing it.
 
+### Store the receipt logo in the Epson
+
+Receipts use NV logo 1 already stored in the printer (`FS p 1 3`, the existing
+`LOGO` constant). Upload a replacement once with:
+
+```sh
+# Stop the kassa backend before uploading.
+.venv/bin/python load_printer_logo.py images/hack42.png --write --test-print
+```
+
+The script reads `pos.serial` from `config.yaml` (default `/dev/ttyKASSA`,
+19200 baud). Use `--config`, `--port`, or `--baudrate` to override it. Without
+`--write` it only prepares the image; `--output logo.bin` exports the `FS q`
+command for offline inspection. `--test-print` prints the stored logo after
+uploading. Restart the backend afterwards.
+
+The default stored width is 192 dots; `LOGO` prints at twice the stored width
+and height, so the printed width is at most 384 dots. `--width` changes the
+stored width. Images retain their aspect ratio; transparent pixels and padding
+become white. Stored logos persist after power-off; receipt generation does not
+upload the image again.
+
+Epson's [FS q command](https://download4.epson.biz/sec_pubs/pos/reference_en/escpos/fs_lq.html)
+replaces **all** existing NV logos/graphics and resets the printer. Run the
+script only when changing the logo, with the backend stopped, and keep the
+printer powered on until it finishes. A successful serial write cannot confirm
+that the printer accepted the logo; verify the test print. The printer must
+support the same legacy NV commands already used for the receipt header.
+
 ### data
 
 Data is stored in 'data'. In production it is also committed to git, but for
diff --git a/load_printer_logo.py b/load_printer_logo.py
new file mode 100644
index 0000000..f3dc6f7
--- /dev/null
+++ b/load_printer_logo.py
@@ -0,0 +1,105 @@
+"""Upload NV logo 1 for the existing Epson FS p receipt header."""
+
+import argparse
+from pathlib import Path
+import struct
+import time
+
+from PIL import Image, ImageOps
+import serial
+
+from config import load_config
+from plugins.POS import CENTER, CUT, FEED, LOGO, PRINTER
+
+
+def encode_logo(path, width=192):
+    """Encode FS q column data; LOGO prints this at twice the stored size."""
+    if not 8 <= width <= 512:
+        raise ValueError("Stored width must be between 8 and 512 dots")
+    with Image.open(path) as source:
+        image = source.convert("RGBA")
+    image.thumbnail((width, 512), Image.Resampling.LANCZOS)
+    white = Image.new("RGBA", image.size, "white")
+    gray = Image.alpha_composite(white, image).convert("L")
+    ink = ImageOps.invert(gray.point(lambda value: 255 if value >= 128 else 0))
+    x_bytes, y_bytes = (image.width + 7) // 8, (image.height + 7) // 8
+    padded = Image.new("1", (x_bytes * 8, y_bytes * 8), 0)
+    padded.paste(ink.convert("1"), (0, 0))
+    # FS q packs each column from top to bottom, most significant bit first.
+    columns = padded.transpose(Image.Transpose.TRANSPOSE).tobytes()
+    return b"\x1cq\x01" + struct.pack("<HH", x_bytes, y_bytes) + columns
+
+
+def upload_logo(port, baudrate, payload, test_print=False):
+    """Write once, then allow the printer to finish its NV write/reset."""
+    with serial.Serial(
+        port=port, baudrate=baudrate, timeout=5, write_timeout=10, exclusive=True
+    ) as printer:
+        data = PRINTER + payload
+        for offset in range(0, len(data), 32):
+            chunk = data[offset : offset + 32]
+            if printer.write(chunk) != len(chunk):
+                raise OSError("Incomplete serial write; logo upload interrupted")
+            time.sleep(0.05)
+        printer.flush()
+        time.sleep(5)
+        if test_print:
+            proof = PRINTER + CENTER + LOGO + FEED + CUT
+            if printer.write(proof) != len(proof):
+                raise OSError("Incomplete serial write during test print")
+            printer.flush()
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(
+        description="Store Epson NV logo 1. Replaces ALL existing NV logos. "
+        "Stop the kassa backend first and keep the printer powered on."
+    )
+    parser.add_argument(
+        "image",
+        nargs="?",
+        type=Path,
+        default=Path(__file__).resolve().parent / "images/hack42.png",
+    )
+    parser.add_argument(
+        "--width",
+        type=int,
+        default=192,
+        help="stored width in dots; receipts print at 2x (default: 192)",
+    )
+    parser.add_argument("--config", type=Path, help="config.yaml override")
+    parser.add_argument("--port", help="override pos.serial.port")
+    parser.add_argument("--baudrate", type=int, help="override pos.serial.baudrate")
+    parser.add_argument(
+        "--output", type=Path, help="export FS q bytes to a file"
+    )
+    parser.add_argument("--write", action="store_true", help="replace printer NV logos")
+    parser.add_argument(
+        "--test-print", action="store_true", help="print logo after upload"
+    )
+    args = parser.parse_args(argv)
+    if args.test_print and not args.write:
+        parser.error("--test-print requires --write")
+    try:
+        payload = encode_logo(args.image, args.width)
+        if args.output:
+            args.output.write_bytes(payload)
+        if args.write:
+            settings = load_config(args.config)["pos"]["serial"]
+            upload_logo(
+                args.port or settings["port"],
+                args.baudrate or int(settings["baudrate"]),
+                payload,
+                args.test_print,
+            )
+            print("NV logo 1 sent to printer; verify with a test print.")
+        else:
+            print(
+                f"Prepared {len(payload)} bytes. Use --write to replace printer NV logos."
+            )
+    except (OSError, ValueError, serial.SerialException) as exc:
+        parser.exit(1, f"Logo upload failed: {exc}\n")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/test_load_printer_logo.py b/tests/test_load_printer_logo.py
new file mode 100644
index 0000000..b6a3974
--- /dev/null
+++ b/tests/test_load_printer_logo.py
@@ -0,0 +1,116 @@
+from pathlib import Path
+import runpy
+import struct
+from unittest.mock import Mock, patch
+
+from PIL import Image
+import pytest
+
+import load_printer_logo as loader
+from plugins.POS import CENTER, CUT, FEED, LOGO, PRINTER
+
+
+def test_column_encoding_transparency_and_padding(tmp_path):
+    path = tmp_path / "logo.png"
+    image = Image.new("RGBA", (9, 9), (0, 0, 0, 0))
+    image.putpixel((0, 0), (0, 0, 0, 255))
+    image.putpixel((8, 8), (0, 0, 0, 255))
+    image.save(path)
+
+    payload = loader.encode_logo(path)
+
+    expected = bytearray(32)
+    expected[0] = 0x80
+    expected[17] = 0x80
+    assert payload == b"\x1cq\x01" + struct.pack("<HH", 2, 2) + expected
+
+
+def test_logo_scales_proportionally(tmp_path):
+    path = tmp_path / "logo.png"
+    Image.new("RGB", (32, 16), "black").save(path)
+    assert loader.encode_logo(path, 16) == (
+        b"\x1cq\x01" + struct.pack("<HH", 2, 1) + b"\xff" * 16
+    )
+
+
+@pytest.mark.parametrize("width", [0, 513])
+def test_invalid_width_does_not_load_or_upload(width):
+    with pytest.raises(ValueError):
+        loader.encode_logo("missing.png", width)
+
+
+@pytest.mark.parametrize("test_print", [False, True])
+def test_upload_writes_complete_command_and_optional_existing_logo(test_print):
+    printer = Mock()
+    printer.write.side_effect = len
+    payload = b"\x1cq\x01" + bytes(80)
+    with patch.object(loader.serial, "Serial") as serial_mock, patch.object(
+        loader.time, "sleep"
+    ):
+        serial_mock.return_value.__enter__.return_value = printer
+        loader.upload_logo("/dev/test", 19200, payload, test_print)
+
+    serial_mock.assert_called_once_with(
+        port="/dev/test", baudrate=19200, timeout=5, write_timeout=10, exclusive=True
+    )
+    written = b"".join(call.args[0] for call in printer.write.call_args_list)
+    proof = PRINTER + CENTER + LOGO + FEED + CUT if test_print else b""
+    assert written == PRINTER + payload + proof
+    assert printer.flush.call_count == (2 if test_print else 1)
+
+
+@pytest.mark.parametrize("results", [[0], [len(PRINTER) + 1, 0]])
+def test_upload_rejects_short_writes(results):
+    with patch.object(loader.serial, "Serial") as serial_mock, patch.object(
+        loader.time, "sleep"
+    ):
+        serial_mock.return_value.__enter__.return_value.write.side_effect = results
+        with pytest.raises(OSError, match="Incomplete serial write"):
+            loader.upload_logo("/dev/test", 19200, b"x", test_print=True)
+
+
+def test_cli_default_is_offline_and_exports_payload(tmp_path, capsys):
+    output = tmp_path / "logo.bin"
+    with patch.object(loader, "upload_logo") as upload:
+        loader.main(["--output", str(output)])
+    upload.assert_not_called()
+    assert output.read_bytes().startswith(b"\x1cq\x01")
+    assert "Use --write" in capsys.readouterr().out
+
+
+def test_cli_uses_serial_config(tmp_path, capsys):
+    config = tmp_path / "config.yaml"
+    config.write_text(
+        "pos:\n  serial:\n    port: /dev/configured\n    baudrate: 9600\n"
+    )
+    with patch.object(loader, "upload_logo") as upload:
+        loader.main(["--config", str(config), "--write", "--test-print"])
+    assert upload.call_args.args[:2] == ("/dev/configured", 9600)
+    assert upload.call_args.args[3] is True
+    assert "verify with a test print" in capsys.readouterr().out
+
+
+def test_cli_serial_overrides():
+    with patch.object(loader, "upload_logo") as upload:
+        loader.main(["--write", "--port", "/dev/override", "--baudrate", "4800"])
+    assert upload.call_args.args[:2] == ("/dev/override", 4800)
+
+
+def test_cli_print_requires_write():
+    with pytest.raises(SystemExit) as error:
+        loader.main(["--test-print"])
+    assert error.value.code == 2
+
+
+def test_cli_serial_error_has_nonzero_exit(capsys):
+    with patch.object(loader, "upload_logo", side_effect=OSError("port busy")):
+        with pytest.raises(SystemExit) as error:
+            loader.main(["--write"])
+    assert error.value.code == 1
+    assert "port busy" in capsys.readouterr().err
+
+
+def test_cli_entrypoint_is_offline(capsys):
+    with patch("sys.argv", ["load_printer_logo.py"]):
+        runpy.run_path(str(Path(loader.__file__)), run_name="__main__")
+    assert "Use --write" in capsys.readouterr().out

From 872711e3adfe825e6b5347d7f7f95ac535954638 Mon Sep 17 00:00:00 2001
From: Mendel Mobach <mendel@mobach.nl>
Date: Fri, 16 Oct 2026 18:53:09 +0200
Subject: [PATCH 5/5] Format upload script CLI option

---
 load_printer_logo.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/load_printer_logo.py b/load_printer_logo.py
index f3dc6f7..7c4154d 100644
--- a/load_printer_logo.py
+++ b/load_printer_logo.py
@@ -70,9 +70,7 @@ def main(argv=None):
     parser.add_argument("--config", type=Path, help="config.yaml override")
     parser.add_argument("--port", help="override pos.serial.port")
     parser.add_argument("--baudrate", type=int, help="override pos.serial.baudrate")
-    parser.add_argument(
-        "--output", type=Path, help="export FS q bytes to a file"
-    )
+    parser.add_argument("--output", type=Path, help="export FS q bytes to a file")
     parser.add_argument("--write", action="store_true", help="replace printer NV logos")
     parser.add_argument(
         "--test-print", action="store_true", help="print logo after upload"