Kobo Clara BW

Kobo Clara BW e-reader.

  • CPU: 1.0 GHz
  • memory: 512 MB
  • screen : E Ink Carta 1300 HD, 1448 x 1072, 300 ppi
  • screen size: 6 inch
  • storage: 16 GB
  • network: wireless - Wi-Fi 5
  • USB-C
  • bluetooth
  • battery: 1500 mAh
  • waterproof: IPX8
  • size: 159 x 112 x 9.2 mm
  • weight: 174 grams

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Links

Kobo Clara BW, Tips to keep and maintenance your Kobo, Kobo new user, Calibre My device is not being detected by calibre?,

kobopatch, NickelMenu,

KOReader, Plato,

local links

c2,

History

2025-12-03: battery - this morning, on the train to work, the reader warned that battery level was 10% and adviseed me to charge it. So I charged it at work.

2025-11-13: Clara - ok, I turned off "pinch to change font size" in Settings, Reading settings.

2025-11-11: Clara - annoyance - sometimes, I manage to activate the "zoom" or "change font size" gesture while trying to turn the page. I wish it was possible to tunr it off.

2025-07-20: c2 - Calibre has a "eject device" on the menu (when a device is connected), I'll try to use that one, see if it helps. Yup, that is the way to do it.

2025-07-20: c2 - ok, bsdisks somehow cached old, stale data under '/media/KOBOeReader/'. after killing bsdisks and trying again things look better.

2025-07-20: c2 - and Calibre debug device detection says

calibre 8.5  embedded-python: False
FreeBSD-13.5-RELEASE-amd64-64bit-ELF FreeBSD ('64bit', 'ELF')
('FreeBSD', '13.5-RELEASE', 'FreeBSD 13.5-RELEASE releng/13.5-n259162-882b9f3f2218 GENERIC')
Python 3.11.13
Interface language: None
EXE path: /usr/local/bin/python3.11
Successfully initialized third party plugins: Kobo Utilities (2, 23, 0)
USB devices on system:
[['0x46d', '0xc52b', '0x2411', 'Logitech', 'USB Receiver', None],
 ['0x2237', '0x4237', '0x409', 'Kobo', 'eReader-4.42.23296', 'P365532003625'],
 ['0x46d', '0xc52f', '0x3000', 'Logitech', 'USB Receiver', None]]

No disabled plugins
Looking for devices of type: MTP_DEVICE
No MTP devices connected to system

Looking for devices of type: SMART_DEVICE_APP
All IP addresses {'re0': [{'addr': '10.1.150.52', 'netmask': '255.255.0.0', 'broadcast': '10.1.255.255'}], 'lo0': [{'addr': '127.0.0.1', 'netmask': '255.0.0.0'}]}
No device is connected

Looking for devices...
USBDevice(busnum=1, devnum=8, vendor_id=0x2237, product_id=0x4237, bcd=0x0409, manufacturer=Kobo, product=eReader-4.42.23296, serial=P365532003625)
        Detected possible device KOBOTOUCH

Devices possibly connected: KoboTouch,  
Trying to open KoboTouch ... FBSD:  mounted /dev/da5 on /media/KOBOeReader/
FBSD:   main =  /media/KOBOeReader/
DEBUG:  305.4 device_version_info - start
DEBUG:  305.4 device_version_info - version_file=/media/KOBOeReader/.kobo/version
DEBUG:  305.4 device_version_info - have opened version_file
DEBUG:  305.4 device_version_info - self._device_version_info= ['P365532003625', '4.9.77', '4.42.23296', '4.9.77', '4.9.77', '00000000-0000-0000-0000-000000000395']
DEBUG:  305.4 Kobo: I/O error connecting to /media/KOBOeReader/.kobo/KoboReader.sqlite copying it into temporary storage and connecting there
failed
Opening of the following devices failed
Driver:KoboTouch, Options - format_map: ['kepub', 'epub', 'pdf', 'txt', 'cbz', 'cbr'], use_subdirs: True, read_metadata: True, use_author_sort: False, save_template: {author_sort}/{title} - {authors}, extra_customization: [], manage_collections: True, use_collections_columns: True, collections_columns: , use_collections_template: False, collections_template: , use_series_index_template: False, series_index_template: , create_collections: False, delete_empty_collections: False, ignore_collections_names: , upload_covers: False, dithered_covers: False, keep_cover_aspect: False, upload_grayscale: False, letterbox_fs_covers: False, letterbox_fs_covers_color: #000000, png_covers: False, show_archived_books: False, show_previews: False, show_recommendations: False, update_series: True, force_series_id: False, update_core_metadata: False, update_purchased_kepubs: False, update_device_metadata: True, update_subtitle: False, subtitle_template: , update_bookstats: False, bookstats_wordcount_template: , bookstats_pagecount_template: , bookstats_timetoread_upper_template: , bookstats_timetoread_lower_template: , kepubify: True, template_for_kepubify: , modify_css: False, per_device_css: {}, override_kobo_replace_existing: True, affect_hyphenation: False, disable_hyphenation: False, hyphenation_min_chars: 6, hyphenation_min_chars_before: 3, hyphenation_min_chars_after: 3, hyphenation_limit_lines: 2, support_newer_firmware: True, debugging_title: , driver_version: 2.6.0
Traceback (most recent call last):
  File "/usr/local/lib/calibre/calibre/devices/kobo/db.py", line 69, in __init__
    connect()
  File "/usr/local/lib/calibre/calibre/devices/kobo/db.py", line 59, in connect
    cursor.execute('SELECT version FROM dbversion')
  File "src/cursor.c", line 970, in APSWCursor_execute.sqlite3_prepare_v3
apsw.IOError: IOError: disk I/O error

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/calibre/calibre/devices/__init__.py", line 166, in debug
    dev.open(det, None)
  File "/usr/local/lib/calibre/calibre/devices/usbms/device.py", line 863, in open
    self.post_open_callback()
  File "/usr/local/lib/calibre/calibre/devices/kobo/driver.py", line 1616, in post_open_callback
    self.db_manager = Database(self.device_database_path)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/calibre/calibre/devices/kobo/db.py", line 74, in __init__
    shutil.copyfileobj(src, dest)
  File "/usr/local/lib/python3.11/shutil.py", line 197, in copyfileobj
    buf = fsrc_read(length)
          ^^^^^^^^^^^^^^^^^
OSError: [Errno 6] Device not configured

2025-07-20: c2 - and now Calibre (8.5) has stopped recognizing the Clara BW. It shows up on the machine, both in usbconfig and as a disk ('/media/KOBOeReader'), but Calibre will not recognize it. Oh well.

2025-07-19: c2 - I added a devd conf file to allow my user acces to the Kobo Clara BW when connected via usb

tingo@kg-core2:~ $ cat /usr/local/etc/devd/koboclara.conf 
# Kobo Clara BW - allow the group (operator) to access the usb connection
notify 100 {
        match "system"          "USB";
        match "subsystem"       "INTERFACE";
        match "type"            "ATTACH";
        match "vendor" "0x2237";
        match "product" "0x4237";
        action "usb_devaddr=`echo $cdev | sed 's#^ugen##'` && chmod g+rw /dev/usb/${usb_devaddr}.*";
};

and then did service devd restart to enable it. Now Calibre detects the Kobo when connected, and I can transfer books to it. Nice.

2025-07-19: c2 - the Kobo show up like this on my main workstation

root@kg-core2:~ # usbconfig -d ugen1.8
ugen1.8: <Kobo eReader-4.42.23296> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)

device description

root@kg-core2:~ # usbconfig -d ugen1.8 dump_device_desc
ugen1.8: <Kobo eReader-4.42.23296> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)

  bLength = 0x0012 
  bDescriptorType = 0x0001 
  bcdUSB = 0x0200 
  bDeviceClass = 0x0000  <Probed by interface class>
  bDeviceSubClass = 0x0000 
  bDeviceProtocol = 0x0000 
  bMaxPacketSize0 = 0x0040 
  idVendor = 0x2237 
  idProduct = 0x4237 
  bcdDevice = 0x0409 
  iManufacturer = 0x0001  <Kobo>
  iProduct = 0x0002  <eReader-4.42.23296>
  iSerialNumber = 0x0003  <P365532003625>
  bNumConfigurations = 0x0001

current config descriptor

root@kg-core2:~ # usbconfig -d ugen1.8 dump_curr_config_desc
ugen1.8: <Kobo eReader-4.42.23296> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)


 Configuration index 0

    bLength = 0x0009 
    bDescriptorType = 0x0002 
    wTotalLength = 0x0020 
    bNumInterfaces = 0x0001 
    bConfigurationValue = 0x0001 
    iConfiguration = 0x0004  <KOBOeReader>
    bmAttributes = 0x0080 
    bMaxPower = 0x00fa 

    Interface 0
      bLength = 0x0009 
      bDescriptorType = 0x0004 
      bInterfaceNumber = 0x0000 
      bAlternateSetting = 0x0000 
      bNumEndpoints = 0x0002 
      bInterfaceClass = 0x0008  <Mass storage>
      bInterfaceSubClass = 0x0006 
      bInterfaceProtocol = 0x0050 
      iInterface = 0x0005  <Mass Storage>

     Endpoint 0
        bLength = 0x0007 
        bDescriptorType = 0x0005 
        bEndpointAddress = 0x0081  <IN>
        bmAttributes = 0x0002  <BULK>
        wMaxPacketSize = 0x0200 
        bInterval = 0x0000 
        bRefresh = 0x0000 
        bSynchAddress = 0x0000 

     Endpoint 1
        bLength = 0x0007 
        bDescriptorType = 0x0005 
        bEndpointAddress = 0x0001  <OUT>
        bmAttributes = 0x0002  <BULK>
        wMaxPacketSize = 0x0200 
        bInterval = 0x0001 
        bRefresh = 0x0000 
        bSynchAddress = 0x0000

and this is the permissions

root@kg-core2:~ # ls -l /dev/ugen1.8
lrwxr-xr-x  1 root  wheel  9 Jul 19 21:02 /dev/ugen1.8 -> usb/1.8.0
root@kg-core2:~ # ls -l /dev/usb/1.8.0
crw-------  1 root  operator  0x1fd Jul 19 21:02 /dev/usb/1.8.0

need to fix that.

2025-07-19: I walked to a local Power store and bought one of these for NOK 1749.-