Add support for --no-resize option and --keep-awake functionality

README.md

@@ -19,7 +19,7 @@ $ pip install -r requirements.txt
 # Usage
 ```bash
 $ ./print.py --help
-usage: print.py [-h] [-l {debug,info,warn,error}] [-b {mean-threshold,floyd-steinberg,atkinson,halftone,none}] [-s] [-d DEVICE] [-e ENERGY]
+usage: print.py [-h] [-l {debug,info,warn,error}] [-b {mean-threshold,floyd-steinberg,atkinson,halftone,none}] [-s] [-d DEVICE] [-e ENERGY] [--no-resize]
                 filename
 
 prints an image on your cat thermal printer
@@ -40,6 +40,33 @@ options:
                         services.
   -e ENERGY, --energy ENERGY
                         Thermal energy. Between 0x0000 (light) and 0xffff (darker, default).
+  --no-resize           Disable automatic image resizing. Small images print as-is, 
+                        large images scale to width without changing height.
+```
+
+# New Features
+
+## Image Resize Control
+
+The `--no-resize` option provides more control over image printing:
+
+- By default, images are resized to match printer width
+- With `--no-resize`, small images print at original size
+- Large images are scaled to width while maintaining aspect ratio
+
+Example:
+
+```bash
+# Print without automatic resizing
+./print.py --no-resize test.png
+```
+
+## Printer Keep-Awake
+A keep-awake mechanism can be configured in the manager project to prevent printer sleep mode. This is typically managed externally and can be activated when running the server.
+
+```bash
+# Managed by parent project
+node server.js --keep-awake
 ```
 
 # Example

catprinter/ble.py

@@ -25,10 +25,10 @@
 SCAN_TIMEOUT_S = 10
 
 # Wait time after sending each chunk of data through BLE.
-WAIT_AFTER_EACH_CHUNK_S = 0.02
+WAIT_AFTER_EACH_CHUNK_S = 0.2
 
 # Wait for printer done event timeout.
-WAIT_FOR_PRINTER_DONE_TIMEOUT = 30
+WAIT_FOR_PRINTER_DONE_TIMEOUT = 60
 
 
 async def scan(name: Optional[str], timeout: int):

catprinter/img.py

@@ -120,19 +120,29 @@ def read_img(
     filename,
     print_width,
     img_binarization_algo,
+    no_resize=False
 ):
+
     im = cv2.imread(filename, cv2.IMREAD_GRAYSCALE)
     height = im.shape[0]
     width = im.shape[1]
-    factor = print_width / width
-    resized = cv2.resize(
-        im,
-        (
-            print_width,
-            int(height * factor)
-        ),
-        interpolation=cv2.INTER_AREA)
 
+    if no_resize and width > print_width:
+        # With no_resize: only resize if image width exceeds print width
+        resized = cv2.resize(
+            im,
+            (print_width, int(height * width / print_width)),
+            interpolation=cv2.INTER_AREA
+        )
+    else:
+        # Default behavior: resize to fit print width while maintaining aspect ratio
+        factor = print_width / width
+        resized = cv2.resize(
+            im, 
+            (print_width, int(height * factor)), 
+            interpolation=cv2.INTER_AREA
+        )
+
     if img_binarization_algo == 'atkinson':
         logger.info('⏳ Applying Atkinson dithering to image...')
         resized = atkinson_dither(resized)

dummy-print.py

@@ -0,0 +1,64 @@
+import asyncio
+import contextlib
+from typing import Optional
+import uuid
+from bleak import BleakClient, BleakScanner
+from bleak.backends.device import BLEDevice
+from catprinter import logger
+
+POSSIBLE_SERVICE_UUIDS = [
+    "0000ae30-0000-1000-8000-00805f9b34fb",
+    "0000af30-0000-1000-8000-00805f9b34fb",
+]
+
+TX_CHARACTERISTIC_UUID = "0000ae01-0000-1000-8000-00805f9b34fb"
+RX_CHARACTERISTIC_UUID = "0000ae02-0000-1000-8000-00805f9b34fb"
+
+PRINTER_READY_NOTIFICATION = b"\x51\x78\xae\x01\x01\x00\x00\x00\xff"
+
+SCAN_TIMEOUT_S = 10
+WAIT_AFTER_EACH_CHUNK_S = 0.2
+WAIT_FOR_PRINTER_DONE_TIMEOUT = 60
+
+# Scan and connect to the printer
+async def scan(name: Optional[str], timeout: int):
+    autodiscover = not name
+    if autodiscover:
+        logger.info("⏳ Trying to auto-discover a printer...")
+    else:
+        logger.info(f"⏳ Looking for a BLE device named {name}...")
+    # Filter function for devices
+    def filter_fn(device: BLEDevice, adv_data):
+        if autodiscover:
+            return any(uuid in adv_data.service_uuids for uuid in POSSIBLE_SERVICE_UUIDS)
+        else:
+            return device.name == name
+
+    device = await BleakScanner.find_device_by_filter(filter_fn, timeout=timeout)
+    if device is None:
+        raise RuntimeError("Unable to find printer, make sure it is turned on and in range")
+    logger.info(f"✅ Found printer: {device}")
+    return device
+
+# Simulate a dummy print activity (ping)
+async def run_dummy_print(device: Optional[str]):
+    try:
+        address = await scan(device, timeout=SCAN_TIMEOUT_S)
+    except RuntimeError as e:
+        logger.error(f"🛑 {e}")
+        return
+    logger.info(f"⏳ Connecting to {address}...")
+    async with BleakClient(address) as client:
+        logger.info(f"✅ Connected: {client.is_connected}; MTU: {client.mtu_size}")
+        event = asyncio.Event()
+
+        # Sending a dummy "ping" to the printer to keep it awake
+        logger.info("⏳ Sending dummy signal to the printer...")
+        await client.write_gatt_char(TX_CHARACTERISTIC_UUID, PRINTER_READY_NOTIFICATION)
+        await asyncio.sleep(WAIT_AFTER_EACH_CHUNK_S)
+
+        logger.info("✅ Printer activity simulated successfully. Exiting.")
+
+# Run the dummy print to simulate the interaction with the printer
+if __name__ == "__main__":
+    asyncio.run(run_dummy_print(None)) 

print.py

@@ -32,12 +32,15 @@ def parse_args():
                           'The printer\'s Bluetooth Low Energy (BLE) address '
                           '(MAC address on Linux; UUID on macOS) '
                           'or advertisement name (e.g.: "GT01", "GB02", "GB03"). '
-                          'If omitted, the the script will try to auto discover '
+                          'If omitted, the script will try to auto discover '
                           'the printer based on its advertised BLE services.'
                       ))
     args.add_argument('-e', '--energy', type=lambda h: int(h.removeprefix("0x"), 16),
                       help="Thermal energy. Between 0x0000 (light) and 0xffff (darker, default).",
                       default="0xffff")
+    args.add_argument('--no-resize', action='store_true',
+                      help='Disable automatic image resizing')
+
     return args.parse_args()
 
 
@@ -64,6 +67,7 @@ def main():
             args.filename,
             PRINT_WIDTH,
             args.img_binarization_algo,
+            no_resize=args.no_resize
         )
         if args.show_preview:
             show_preview(bin_img)