diff --git a/packages/devices/package.json b/packages/devices/package.json
index 1e09792..750a9fd 100644
--- a/packages/devices/package.json
+++ b/packages/devices/package.json
@@ -15,13 +15,15 @@
     "build": "tsc -b",
     "dev": "tsc -b --watch",
     "typecheck": "tsc --noEmit",
-    "lint": "tsc --noEmit"
+    "lint": "tsc --noEmit",
+    "test": "vitest run"
   },
   "dependencies": {
     "@parking/shared": "workspace:*"
   },
   "devDependencies": {
     "@types/node": "25.9.3",
-    "typescript": "6.0.3"
+    "typescript": "6.0.3",
+    "vitest": "^4.1.9"
   }
 }
diff --git a/packages/devices/src/drivers/printer-escpos.test.ts b/packages/devices/src/drivers/printer-escpos.test.ts
new file mode 100644
index 0000000..351c7f3
--- /dev/null
+++ b/packages/devices/src/drivers/printer-escpos.test.ts
@@ -0,0 +1,116 @@
+import { describe, expect, it } from "vitest";
+import {
+  renderTicket,
+  renderReceipt,
+  renderWindowChargeNotice,
+  renderSubscriptionCard,
+  stamp,
+} from "./printer-escpos.js";
+
+// The ESC/POS renderers are pure (data → Buffer). These tests pin the byte-level
+// invariants that caused real misprints: the CP852 codepage select, the Albanian/
+// punctuation character mapping (no stray "?"), and the Code128 module width — a
+// ~20-char id at width 3 overflows the 80mm head and the firmware silently aborts the
+// barcode, so the out-of-window slip MUST use width 2.
+
+// Command-byte markers (see printer-escpos.ts).
+const SELECT_CP852 = Buffer.from([0x1b, 0x74, 0x12]); // ESC t 18
+const CODE128_PREFIX = [0x1d, 0x6b, 0x49]; // GS k 73 (function B, Code128)
+const GS_W = (w: number) => [0x1d, 0x77, w]; // GS w n — module width
+const QR_PRINT = [0x1d, 0x28, 0x6b, 0x03, 0x00, 0x31, 0x51, 0x30]; // fn 181
+
+function indexOfSeq(buf: Buffer, seq: number[]): number {
+  return buf.indexOf(Buffer.from(seq));
+}
+function hasSeq(buf: Buffer, seq: number[]): boolean {
+  return indexOfSeq(buf, seq) >= 0;
+}
+
+describe("renderTicket", () => {
+  const out = renderTicket({ ticketId: "12345678901", issuedAt: "2026-06-21T10:00:00.000Z" });
+
+  it("selects the CP852 codepage in the preamble", () => {
+    expect(out.includes(SELECT_CP852)).toBe(true);
+  });
+
+  it("emits a Code128 barcode of the ticket id", () => {
+    expect(hasSeq(out, CODE128_PREFIX)).toBe(true);
+    // The id appears as both barcode payload (prefixed {B) and large text.
+    expect(out.includes(Buffer.from("12345678901", "ascii"))).toBe(true);
+  });
+
+  it("uses module width 3 for a short (11-char) ticket id", () => {
+    expect(hasSeq(out, GS_W(3))).toBe(true);
+  });
+});
+
+describe("renderWindowChargeNotice — the scannable out-of-window slip", () => {
+  const out = renderWindowChargeNotice({
+    occurrenceId: "SUBSESS-abcdef0123456789",
+    holderName: "Taras Bulba",
+    at: "2026-06-21T13:21:00.000Z",
+    edge: "entry",
+    windowOpensMin: 20 * 60, // 20:00
+  });
+
+  it("uses module width 2 so the ~20-char occurrence id fits the 80mm head", () => {
+    // This is the fix for the silent no-print: width 3 would overflow ~576 dots.
+    expect(hasSeq(out, GS_W(2))).toBe(true);
+    expect(hasSeq(out, GS_W(3))).toBe(false);
+  });
+
+  it("emits BOTH a Code128 and a QR of the occurrence id (scan two ways)", () => {
+    expect(hasSeq(out, CODE128_PREFIX)).toBe(true);
+    expect(hasSeq(out, QR_PRINT)).toBe(true);
+    expect(out.includes(Buffer.from("SUBSESS-abcdef0123456789", "ascii"))).toBe(true);
+  });
+
+  it("does not emit a literal '?' for the warning sign or em dash (CP852 fallback)", () => {
+    // The title is "PARKIM - JASHTË ORARIT" (ASCII dash) and the pending notice uses
+    // "!" not ⚠. The Ë must map to its CP852 byte 0xD3, never 0x3f.
+    expect(out.includes(0xd3)).toBe(true); // Ë → CP852 0xD3
+  });
+});
+
+describe("CP852 character mapping (the misprint fixes)", () => {
+  it("maps ë to its CP852 byte, not '?'", () => {
+    // A receipt's "Kohëzgjatja" / "Mënyra" lines carry ë.
+    const out = renderReceipt({
+      ticketId: "12345678901",
+      header: { parkName: "Parking Ë" },
+      enteredAt: "2026-06-21T08:00:00.000Z",
+      paidAt: "2026-06-21T10:00:00.000Z",
+      amountMinor: 20000,
+      currency: "ALL",
+      tender: "cash",
+      voucher: false,
+    } as Parameters<typeof renderReceipt>[0]);
+    expect(out.includes(0x89)).toBe(true); // ë → CP852 0x89
+  });
+
+  it("transliterates an em dash to ASCII '-' (no '?') in the validity line", () => {
+    // No validFrom/validTo → the card uses an em dash placeholder "—" which must
+    // degrade to '-'. Count of '?' (0x3f) stays 0 across the buffer.
+    const out = renderSubscriptionCard({
+      code: "SUB-1",
+      header: { parkName: "P" },
+      holderName: "Test",
+      validFrom: null,
+      validTo: null,
+    } as Parameters<typeof renderSubscriptionCard>[0]);
+    // The em dash is replaced by '-' (0x2d); there must be no '?' fallback byte.
+    expect(out.includes(0x3f)).toBe(false);
+  });
+});
+
+describe("stamp (Albanian date format)", () => {
+  it("formats an ISO time as '<day> <Month> <year> HH:MM:SS'", () => {
+    // Local-time dependent, so assert the structure + the Albanian month name.
+    const s = stamp("2026-06-21T10:48:25.000Z");
+    expect(s).toMatch(/Qershor 2026 \d{2}:\d{2}:\d{2}$/);
+  });
+
+  it("passes through an invalid date unchanged", () => {
+    expect(stamp("not-a-date")).toBe("not-a-date");
+  });
+});
diff --git a/packages/devices/src/printer-routing.test.ts b/packages/devices/src/printer-routing.test.ts
new file mode 100644
index 0000000..89f2b0c
--- /dev/null
+++ b/packages/devices/src/printer-routing.test.ts
@@ -0,0 +1,78 @@
+import { describe, expect, it, vi } from "vitest";
+import {
+  orderForRole,
+  printWithFailover,
+  NoPrinterAvailableError,
+  type PrinterInstance,
+} from "./printer-routing.js";
+import type { PrinterDevice } from "./interfaces.js";
+
+// Printer routing is pure selection over (config, health): which printer prints a job,
+// best-first, with failover. The key business rules: the booth printer is a FALLBACK for
+// entry tickets but a receipt NEVER prints on the outside dispenser; rank then id break
+// ties deterministically; printWithFailover walks the order and surfaces all failures.
+
+function inst(id: string, role: PrinterInstance["role"], failoverRank = 0, device?: PrinterDevice): PrinterInstance {
+  return { id, role, failoverRank, device: device ?? ({} as PrinterDevice) };
+}
+
+describe("orderForRole", () => {
+  it("entry-dispenser job: dispensers first, booth-receipt as fallback", () => {
+    const printers = [inst("booth", "booth-receipt"), inst("disp", "entry-dispenser")];
+    expect(orderForRole(printers, "entry-dispenser").map((p) => p.id)).toEqual(["disp", "booth"]);
+  });
+
+  it("booth-receipt job: NEVER falls back to the outside dispenser", () => {
+    const printers = [inst("disp", "entry-dispenser"), inst("booth", "booth-receipt")];
+    expect(orderForRole(printers, "booth-receipt").map((p) => p.id)).toEqual(["booth"]);
+  });
+
+  it("breaks ties by failoverRank (higher first), then id", () => {
+    const printers = [
+      inst("b", "entry-dispenser", 1),
+      inst("a", "entry-dispenser", 1),
+      inst("c", "entry-dispenser", 5),
+    ];
+    expect(orderForRole(printers, "entry-dispenser").map((p) => p.id)).toEqual(["c", "a", "b"]);
+  });
+
+  it("excludes printers of no relevant role", () => {
+    const printers = [inst("booth", "booth-receipt")];
+    expect(orderForRole(printers, "booth-receipt").map((p) => p.id)).toEqual(["booth"]);
+    // For a receipt job, an entry dispenser is excluded entirely.
+    expect(orderForRole([inst("disp", "entry-dispenser")], "booth-receipt")).toEqual([]);
+  });
+});
+
+describe("printWithFailover", () => {
+  function device(behavior: "ok" | "fail"): PrinterDevice {
+    return {
+      printTicket: vi.fn(behavior === "ok" ? async () => {} : async () => { throw new Error("offline"); }),
+    } as unknown as PrinterDevice;
+  }
+
+  it("prints on the first healthy candidate and returns its id", async () => {
+    const printers = [inst("disp", "entry-dispenser", 0, device("ok")), inst("booth", "booth-receipt", 0, device("ok"))];
+    const job = vi.fn(async (d: PrinterDevice) => d.printTicket({} as never));
+    const used = await printWithFailover(printers, "entry-dispenser", job);
+    expect(used).toBe("disp");
+    expect(job).toHaveBeenCalledTimes(1);
+  });
+
+  it("fails over to the booth printer when the dispenser throws", async () => {
+    const printers = [inst("disp", "entry-dispenser", 0, device("fail")), inst("booth", "booth-receipt", 0, device("ok"))];
+    const used = await printWithFailover(printers, "entry-dispenser", (d) => d.printTicket({} as never));
+    expect(used).toBe("booth");
+  });
+
+  it("throws NoPrinterAvailableError listing every failed attempt", async () => {
+    const printers = [inst("disp", "entry-dispenser", 0, device("fail")), inst("booth", "booth-receipt", 0, device("fail"))];
+    await expect(printWithFailover(printers, "entry-dispenser", (d) => d.printTicket({} as never)))
+      .rejects.toBeInstanceOf(NoPrinterAvailableError);
+  });
+
+  it("throws when no printer is configured for the role", async () => {
+    await expect(printWithFailover([], "entry-dispenser", async () => {}))
+      .rejects.toBeInstanceOf(NoPrinterAvailableError);
+  });
+});
diff --git a/packages/devices/tsconfig.json b/packages/devices/tsconfig.json
index 4999a19..7be994f 100644
--- a/packages/devices/tsconfig.json
+++ b/packages/devices/tsconfig.json
@@ -7,5 +7,6 @@
     "types": ["node"]
   },
   "references": [{ "path": "../shared" }],
-  "include": ["src/**/*"]
+  "include": ["src/**/*"],
+  "exclude": ["src/**/*.test.ts"]
 }
diff --git a/packages/devices/vitest.config.ts b/packages/devices/vitest.config.ts
new file mode 100644
index 0000000..3a19563
--- /dev/null
+++ b/packages/devices/vitest.config.ts
@@ -0,0 +1,9 @@
+import { defineConfig } from "vitest/config";
+
+// Device tests are pure byte-stream assertions over the ESC/POS renderers + the
+// printer-routing logic — no sockets, no hardware. Run from src (not dist).
+export default defineConfig({
+  test: {
+    include: ["src/**/*.test.ts"],
+  },
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 635801e..d76a4b8 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -186,6 +186,9 @@ importers:
       typescript:
         specifier: 6.0.3
         version: 6.0.3
+      vitest:
+        specifier: ^4.1.9
+        version: 4.1.9(@types/node@25.9.3)(vite@8.0.16(@types/node@25.9.3)(esbuild@0.28.1)(jiti@2.7.0)(tsx@4.22.4))
 
   packages/shared:
     devDependencies: