RE: OTA zip upload issue.

Embel_Tech — Sat, 28 Mar 2026 06:52:16 GMT
Hello Abhijith,
I am using an nRF52833 custom board with SDK version 2.9.0. I am encountering an issue where error code -28 appears in the RTT logs.
I have uploaded the ZIP file, but I have not yet tried using the BIN file.
I will share the RTT logs separately for your reference. Could you please review and help identify the cause of this issue?
RF Connect, 2026-03-28
Handheld_Ota (C3:CC:AC:9C:D2:13)
V 11:35:35.364 Connecting to C3:CC:AC:9C:D2:13...
D 11:35:35.364 gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE, preferred PHY = LE 1M)
D 11:35:39.596 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
D 11:35:39.596 [Callback] Connection state changed with status: 0 and new state: CONNECTED (2)
I 11:35:39.596 Connected to C3:CC:AC:9C:D2:13
V 11:35:39.621 Discovering services...
D 11:35:39.621 gatt.discoverServices()
D 11:35:39.792 [Broadcast] Action received: android.bluetooth.device.action.BOND_STATE_CHANGED, bond state changed to: BONDING (11)
D 11:35:39.824 [Broadcast] Action received: android.bluetooth.device.extra.PAIRING_VARIANT, pairing variant: CONSENT
I 11:35:40.028 Connection parameters updated (interval: 7.5ms, latency: 0, timeout: 5000ms)
D 11:35:40.329 [Callback] Services discovered with status: 0
I 11:35:40.329 Services discovered
V 11:35:40.349 Generic Attribute (0x1801)
- Service Changed [I] (0x2A05)
   Client Characteristic Configuration (0x2902)
Generic Access (0x1800)
- Device Name [R] (0x2A00)
- Appearance [R] (0x2A01)
Unknown Service (0000b000-4375-7274-204d-6667204c4c43)
- Unknown Characteristic [N] (0000b001-1212-efde-1523-785feabcd123)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [R] (0000b002-1212-efde-1523-785feabcd123)
- Unknown Characteristic [R W] (0000b003-1212-efde-1523-785feabcd123)
   Characteristic User Description (0x2901)
- Unknown Characteristic [W] (0000b004-1212-efde-1523-785feabcd123)
SMP Service (8d53dc1d-1db7-4cd3-868b-8a527460aa84)
- SMP Characteristic [N WNR] (da2e7828-fbce-4e01-ae9e-261174997c48)
   Client Characteristic Configuration (0x2902)
D 11:35:40.349 gatt.setCharacteristicNotification(00002a05-0000-1000-8000-00805f9b34fb, true)
D 11:35:40.351 gatt.setCharacteristicNotification(0000b001-1212-efde-1523-785feabcd123, true)
I 11:35:40.432 Connection parameters updated (interval: 45.0ms, latency: 0, timeout: 5000ms)
D 11:35:44.354 [Broadcast] Action received: android.bluetooth.device.action.BOND_STATE_CHANGED, bond state changed to: NONE (10), reason: REMOVED (9)
I 11:35:44.354 Bonding failed, reason: REMOVED (9)
D 11:35:44.388 [Callback] Connection state changed with status: 5 and new state: DISCONNECTED (0)
E 11:35:44.388 Error 5 (0x5): UNKNOWN (5)
I 11:35:44.388 Disconnected
D 11:35:44.462 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
D 11:35:46.206 gatt.close()
D 11:35:46.212 wait(200)
V 11:35:46.413 Connecting to C3:CC:AC:9C:D2:13...
D 11:35:46.413 gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE, preferred PHY = LE 1M)
D 11:35:47.551 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
D 11:35:47.557 [Callback] Connection state changed with status: 0 and new state: CONNECTED (2)
I 11:35:47.557 Connected to C3:CC:AC:9C:D2:13
V 11:35:47.559 Discovering services...
D 11:35:47.559 gatt.discoverServices()
D 11:35:47.762 [Broadcast] Action received: android.bluetooth.device.action.BOND_STATE_CHANGED, bond state changed to: BONDING (11)
D 11:35:47.807 [Broadcast] Action received: android.bluetooth.device.extra.PAIRING_VARIANT, pairing variant: CONSENT
I 11:35:47.990 Connection parameters updated (interval: 7.5ms, latency: 0, timeout: 5000ms)
D 11:35:48.307 [Callback] Services discovered with status: 0
I 11:35:48.307 Services discovered
V 11:35:48.316 Generic Attribute (0x1801)
- Service Changed [I] (0x2A05)
   Client Characteristic Configuration (0x2902)
Generic Access (0x1800)
- Device Name [R] (0x2A00)
- Appearance [R] (0x2A01)
Unknown Service (0000b000-4375-7274-204d-6667204c4c43)
- Unknown Characteristic [N] (0000b001-1212-efde-1523-785feabcd123)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [R] (0000b002-1212-efde-1523-785feabcd123)
- Unknown Characteristic [R W] (0000b003-1212-efde-1523-785feabcd123)
   Characteristic User Description (0x2901)
- Unknown Characteristic [W] (0000b004-1212-efde-1523-785feabcd123)
SMP Service (8d53dc1d-1db7-4cd3-868b-8a527460aa84)
- SMP Characteristic [N WNR] (da2e7828-fbce-4e01-ae9e-261174997c48)
   Client Characteristic Configuration (0x2902)
D 11:35:48.317 gatt.setCharacteristicNotification(00002a05-0000-1000-8000-00805f9b34fb, true)
D 11:35:48.317 gatt.setCharacteristicNotification(0000b001-1212-efde-1523-785feabcd123, true)
I 11:35:48.394 Connection parameters updated (interval: 45.0ms, latency: 0, timeout: 5000ms)
D 11:35:49.509 [Broadcast] Action received: android.bluetooth.device.extra.PAIRING_VARIANT, pairing variant: PIN
D 11:36:00.864 [Broadcast] Action received: android.bluetooth.device.action.BOND_STATE_CHANGED, bond state changed to: BONDED (12)
I 11:36:00.864 Device bonded
V 11:36:01.512 [McuMgr] Connecting...
D 11:36:01.530 [McuMgr] gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE, LE 1M)
D 11:36:01.594 [McuMgr] [Callback] Connection state changed with status: 0 and new state: 2 (CONNECTED)
I 11:36:01.607 [McuMgr] Connected to C3:CC:AC:9C:D2:13
D 11:36:01.616 [McuMgr] wait(1600)
V 11:36:03.226 [McuMgr] Discovering services...
D 11:36:03.238 [McuMgr] gatt.discoverServices()
I 11:36:03.268 [McuMgr] Services discovered
V 11:36:03.281 [McuMgr] Primary service found
V 11:36:03.307 [McuMgr] Requesting new MTU...
D 11:36:03.322 [McuMgr] gatt.requestMtu(498)
I 11:36:03.431 [McuMgr] MTU changed to: 247
D 11:36:03.453 [McuMgr] gatt.setCharacteristicNotification(da2e7828-fbce-4e01-ae9e-261174997c48, true)
V 11:36:03.473 [McuMgr] Enabling notifications for da2e7828-fbce-4e01-ae9e-261174997c48
D 11:36:03.484 [McuMgr] descriptor.setValue(0x01-00)
D 11:36:03.496 [McuMgr] gatt.writeDescriptor(00002902-0000-1000-8000-00805f9b34fb)
I 11:36:03.562 [McuMgr] Data written to descr. 00002902-0000-1000-8000-00805f9b34fb
I 11:36:03.572 [McuMgr] Notifications enabled
V 11:36:03.589 [McuMgr] Waiting for value change...
V 11:36:03.600 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:36:03.611 [McuMgr] characteristic.setValue(0x000000010000FF06A0)
D 11:36:03.621 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:36:03.632 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:36:03.647 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:36:03.743 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 01-00-00-19-00-00-FF-06-BF-68-62-75-66-5F-73-69-7A-65-19-09-AB-69-62-75-66-5F-63-6F-75-6E-74-04-FF
I 11:36:03.754 [McuMgr] Wait for value changed complete
A 11:36:03.777 [McuMgr] Received Header (Version: 0, Op: 1, Flags: 0, Len: 25, Group: 0, Seq: 255, Command: 6) CBOR {"buf_size":2475,"buf_count":4}
I 11:36:03.803 [McuMgr] SMP reassembly supported with buffer size: 2475 bytes and count: 4
V 11:36:03.817 [McuMgr] Requesting connection priority: HIGH (11.25–15ms, 0, 5s)...
D 11:36:03.826 [McuMgr] gatt.requestConnectionPriority(HIGH)
A 11:36:03.839 [McuMgr] Sending (9 bytes) Header (Version: 1, Op: 0, Flags: 0, Len: 1, Group: 0, Seq: 0, Command: 8) CBOR {}
V 11:36:04.035 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:36:04.052 [McuMgr] characteristic.setValue(0x0800000100000008A0)
D 11:36:04.064 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:36:04.077 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:36:04.092 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:36:04.146 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 09-00-00-15-00-00-00-08-BF-6A-62-6F-6F-74-6C-6F-61-64-65-72-67-4D-43-55-62-6F-6F-74-FF
A 11:36:04.158 [McuMgr] Received Header (Version: 1, Op: 1, Flags: 0, Len: 21, Group: 0, Seq: 0, Command: 8) CBOR {"bootloader":"MCUboot"}
A 11:36:04.200 [McuMgr] Sending (20 bytes) Header (Version: 1, Op: 0, Flags: 0, Len: 12, Group: 0, Seq: 1, Command: 8) CBOR {"query":"mode"}
V 11:36:04.210 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:36:04.220 [McuMgr] characteristic.setValue(0x0800000C00000108A1657175657279646D6F6465)
D 11:36:04.230 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:36:04.238 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:36:04.249 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:36:04.281 Connection parameters updated (interval: 15.0ms, latency: 0, timeout: 5000ms)
I 11:36:04.290 [McuMgr] Connection parameters updated (interval: 15.0ms, latency: 0, timeout: 5000ms)
I 11:36:04.302 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 09-00-00-08-00-00-01-08-BF-64-6D-6F-64-65-03-FF
A 11:36:04.314 [McuMgr] Received Header (Version: 1, Op: 1, Flags: 0, Len: 8, Group: 0, Seq: 1, Command: 8) CBOR {"mode":3}
A 11:36:04.333 [McuMgr] Sending (9 bytes) Header (Version: 1, Op: 0, Flags: 0, Len: 1, Group: 1, Seq: 2, Command: 0) CBOR {}
V 11:36:04.341 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:36:04.348 [McuMgr] characteristic.setValue(0x0800000100010200A0)
D 11:36:04.354 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:36:04.364 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:36:04.385 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:36:04.415 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 09-00-00-88-00-01-02-00-BF-66-69-6D-61-67-65-73-9F-BF-64-73-6C-6F-74-00-67-76-65-72-73-69-6F-6E-67-32-2E-30-2E-35-2E-39-64-68-61-73-68-58-20-A0-44-86-C8-BD-51-83-20-8E-6C-20-B9-A1-69-40-84-9C-65-5D-A8-B1-07-FF-42-E2-1E-02-81-09-98-27-5F-68-62-6F-6F-74-61-62-6C-65-F5-67-70-65-6E-64-69-6E-67-F4-69-63-6F-6E-66-69-72-6D-65-64-F5-66-61-63-74-69-76-65-F5-69-70-65-72-6D-61-6E-65-6E-74-F4-FF-FF-6B-73-70-6C-69-74-53-74-61-74-75-73-00-FF
A 11:36:04.424 [McuMgr] Received Header (Version: 1, Op: 1, Flags: 0, Len: 136, Group: 1, Seq: 2, Command: 0) CBOR {"images":[{"slot":0,"version":"2.0.5.9","hash":"oESGyL1RgyCObCC5oWlAhJxlXaixB/9C4h4CgQmYJ18=","bootable":true,"pending":false,"confirmed":true,"active":true,"permanent":false}],"splitStatus":0}
V 11:36:04.462 [McuMgr] Uploading firmware...
D 11:36:09.569 [Callback] Connection state changed with status: 8 and new state: DISCONNECTED (0)
E 11:36:09.569 Error 8 (0x8): GATT CONN TIMEOUT
I 11:36:09.569 Disconnected
W 11:36:09.596 [McuMgr] Error: (0x8): GATT CONN TIMEOUT
D 11:36:09.621 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
W 11:36:14.665 [McuMgr] Error: (0x85): GATT ERROR
W 11:36:20.421 [McuMgr] Error: (0x85): GATT ERROR
W 11:36:26.174 [McuMgr] Error: (0x85): GATT ERROR
D 11:36:27.690 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
W 11:36:35.472 [McuMgr] Error: (0x8): GATT CONN TIMEOUT
D 11:36:35.520 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
W 11:36:40.565 [McuMgr] Error: (0x85): GATT ERROR
W 11:36:46.320 [McuMgr] Error: (0x85): GATT ERROR
W 11:36:52.073 [McuMgr] Error: (0x85): GATT ERROR
D 11:36:53.575 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
W 11:37:01.351 [McuMgr] Error: (0x8): GATT CONN TIMEOUT
D 11:37:01.386 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
W 11:37:06.433 [McuMgr] Error: (0x85): GATT ERROR
W 11:37:12.202 [McuMgr] Error: (0x85): GATT ERROR
W 11:37:17.950 [McuMgr] Error: (0x85): GATT ERROR
D 11:37:19.446 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
A 11:37:34.330 [McuMgr] 174355 bytes sent in 64216 ms (2.72 kB/s)
V 11:37:34.347 [McuMgr] New state: TEST
A 11:37:34.392 [McuMgr] Sending (57 bytes) Header (Version: 1, Op: 2, Flags: 0, Len: 49, Group: 1, Seq: 67, Command: 0) CBOR {"confirm":false,"hash":"JML6yWUZSUcruxziBcZ06giagdLA+JjMv3BBZLIDLR0="}
V 11:37:34.402 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:37:34.410 [McuMgr] characteristic.setValue(0x0A00003100014300A267636F6E6669726DF46468617368582024C2FAC9651949472BBB1CE205C674EA089A81D2C0F898CCBF704164B2032D1D)
D 11:37:34.418 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:37:34.426 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:37:34.435 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:37:34.513 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 0B-00-00-F8-00-01-43-00-BF-66-69-6D-61-67-65-73-9F-BF-64-73-6C-6F-74-00-67-76-65-72-73-69-6F-6E-67-32-2E-30-2E-35-2E-39-64-68-61-73-68-58-20-A0-44-86-C8-BD-51-83-20-8E-6C-20-B9-A1-69-40-84-9C-65-5D-A8-B1-07-FF-42-E2-1E-02-81-09-98-27-5F-68-62-6F-6F-74-61-62-6C-65-F5-67-70-65-6E-64-69-6E-67-F4-69-63-6F-6E-66-69-72-6D-65-64-F5-66-61-63-74-69-76-65-F5-69-70-65-72-6D-61-6E-65-6E-74-F4-FF-BF-64-73-6C-6F-74-01-67-76-65-72-73-69-6F-6E-67-31-2E-30-2E-30-2E-35-64-68-61-73-68-58-20-24-C2-FA-C9-65-19-49-47-2B-BB-1C-E2-05-C6-74-EA-08-9A-81-D2-C0-F8-98-CC-BF-70-41-64-B2-03-2D-1D-68-62-6F-6F-74-61-62-6C-65-F5-67-70-65-6E-64-69-6E-67-F5-69-63-6F-6E-66-69-72-6D-65-64-F4-66-61-63-74-69-76-65-F4-69-70-65-72-6D-61-6E-65-6E-74-F4-FF-FF-6B-73
I 11:37:34.527 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 70-6C-69-74-53-74-61-74-75-73-00-FF
A 11:37:34.537 [McuMgr] Received Header (Version: 1, Op: 3, Flags: 0, Len: 248, Group: 1, Seq: 67, Command: 0) CBOR {"images":[{"slot":0,"version":"2.0.5.9","hash":"oESGyL1RgyCObCC5oWlAhJxlXaixB/9C4h4CgQmYJ18=","bootable":true,"pending":false,"confirmed":true,"active":true,"permanent":false},{"slot":1,"version":"1.0.0.5","hash":"JML6yWUZSUcruxziBcZ06giagdLA+JjMv3BBZLIDLR0=","bootable":true,"pending":true,"confirmed":false,"active":false,"permanent":false}],"splitStatus":0}
V 11:37:34.572 [McuMgr] New state: RESET
A 11:37:34.591 [McuMgr] Sending (9 bytes) Header (Version: 1, Op: 2, Flags: 0, Len: 1, Group: 0, Seq: 68, Command: 5) CBOR {}
V 11:37:34.599 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:37:34.608 [McuMgr] characteristic.setValue(0x0A00000100004405A0)
D 11:37:34.627 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:37:34.634 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:37:34.657 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:37:34.775 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 0B-00-00-02-00-00-44-05-BF-FF
A 11:37:34.789 [McuMgr] Received Header (Version: 1, Op: 3, Flags: 0, Len: 2, Group: 0, Seq: 68, Command: 5) CBOR {}
D 11:37:39.976 [McuMgr] [Callback] Connection state changed with status: 8 and new state: 0 (DISCONNECTED)
W 11:37:40.012 [McuMgr] Error: (0x8): GATT CONN TIMEOUT
I 11:37:40.025 [McuMgr] Disconnected
D 11:37:40.053 [McuMgr] gatt.close()
D 11:37:40.087 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
V 11:37:44.821 [McuMgr] Connecting...
D 11:37:44.834 [McuMgr] gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE, LE 1M)
V 11:37:44.854 [McuMgr] New state: CONFIRM
D 11:37:45.047 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED
D 11:37:45.071 [McuMgr] [Callback] Connection state changed with status: 0 and new state: 2 (CONNECTED)
I 11:37:45.093 [McuMgr] Connected to C3:CC:AC:9C:D2:13
D 11:37:45.105 [McuMgr] wait(1600)
V 11:37:46.715 [McuMgr] Discovering services...
D 11:37:46.731 [McuMgr] gatt.discoverServices()
I 11:37:46.747 [McuMgr] Services discovered
V 11:37:46.756 [McuMgr] Primary service found
V 11:37:46.764 [McuMgr] Requesting new MTU...
D 11:37:46.773 [McuMgr] gatt.requestMtu(498)
I 11:37:46.836 [McuMgr] MTU changed to: 247
D 11:37:46.848 [McuMgr] gatt.setCharacteristicNotification(da2e7828-fbce-4e01-ae9e-261174997c48, true)
V 11:37:46.860 [McuMgr] Enabling notifications for da2e7828-fbce-4e01-ae9e-261174997c48
D 11:37:46.869 [McuMgr] descriptor.setValue(0x01-00)
D 11:37:46.877 [McuMgr] gatt.writeDescriptor(00002902-0000-1000-8000-00805f9b34fb)
I 11:37:46.971 [McuMgr] Data written to descr. 00002902-0000-1000-8000-00805f9b34fb
I 11:37:46.983 [McuMgr] Notifications enabled
V 11:37:46.995 [McuMgr] Waiting for value change...
V 11:37:47.007 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:37:47.015 [McuMgr] characteristic.setValue(0x000000010000FF06A0)
D 11:37:47.023 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:37:47.030 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:37:47.041 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:37:47.107 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 01-00-00-19-00-00-FF-06-BF-68-62-75-66-5F-73-69-7A-65-19-09-AB-69-62-75-66-5F-63-6F-75-6E-74-04-FF
I 11:37:47.119 [McuMgr] Wait for value changed complete
A 11:37:47.129 [McuMgr] Received Header (Version: 0, Op: 1, Flags: 0, Len: 25, Group: 0, Seq: 255, Command: 6) CBOR {"buf_size":2475,"buf_count":4}
I 11:37:47.145 [McuMgr] SMP reassembly supported with buffer size: 2475 bytes and count: 4
A 11:37:47.157 [McuMgr] Sending (57 bytes) Header (Version: 1, Op: 2, Flags: 0, Len: 49, Group: 1, Seq: 0, Command: 0) CBOR {"confirm":true,"hash":"JML6yWUZSUcruxziBcZ06giagdLA+JjMv3BBZLIDLR0="}
V 11:37:47.167 [McuMgr] Writing characteristic da2e7828-fbce-4e01-ae9e-261174997c48 (WRITE COMMAND)
D 11:37:47.176 [McuMgr] characteristic.setValue(0x0A00003100010000A267636F6E6669726DF56468617368582024C2FAC9651949472BBB1CE205C674EA089A81D2C0F898CCBF704164B2032D1D)
D 11:37:47.186 [McuMgr] characteristic.setWriteType(WRITE COMMAND)
D 11:37:47.194 [McuMgr] gatt.writeCharacteristic(da2e7828-fbce-4e01-ae9e-261174997c48)
I 11:37:47.205 [McuMgr] Data written to da2e7828-fbce-4e01-ae9e-261174997c48
I 11:37:47.288 [McuMgr] Notification received from da2e7828-fbce-4e01-ae9e-261174997c48, value: (0x) 0B-00-00-14-00-01-00-00-BF-63-65-72-72-BF-65-67-72-6F-75-70-01-62-72-63-18-1C-FF-FF
A 11:37:47.303 [McuMgr] Received Header (Version: 1, Op: 3, Flags: 0, Len: 20, Group: 1, Seq: 0, Command: 0) CBOR {"err":{"group":1,"rc":28}}
V 11:37:47.337 [McuMgr] Disconnecting...
D 11:37:47.346 [McuMgr] gatt.disconnect()
D 11:37:47.371 [McuMgr] [Callback] Connection state changed with status: 0 and new state: 0 (DISCONNECTED)
I 11:37:47.379 [McuMgr] Disconnected
D 11:37:47.390 [McuMgr] gatt.close()
D 11:37:47.412 gatt.close()
D 11:37:47.418 wait(200)
V 11:37:47.619 Connecting to C3:CC:AC:9C:D2:13...
D 11:37:47.619 gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE, preferred PHY = LE 1M)
D 11:37:47.641 [Callback] Connection state changed with status: 0 and new state: CONNECTED (2)
I 11:37:47.641 Connected to C3:CC:AC:9C:D2:13
D 11:37:47.642 wait(1600ms)
V 11:37:49.243 Discovering services...
D 11:37:49.243 gatt.discoverServices()
D 11:37:49.249 [Callback] Services discovered with status: 0
I 11:37:49.249 Services discovered
V 11:37:49.264 Generic Attribute (0x1801)
- Service Changed [I] (0x2A05)
   Client Characteristic Configuration (0x2902)
Generic Access (0x1800)
- Device Name [R] (0x2A00)
- Appearance [R] (0x2A01)
Unknown Service (0000b000-4375-7274-204d-6667204c4c43)
- Unknown Characteristic [N] (0000b001-1212-efde-1523-785feabcd123)
   Client Characteristic Configuration (0x2902)
- Unknown Characteristic [R] (0000b002-1212-efde-1523-785feabcd123)
- Unknown Characteristic [R W] (0000b003-1212-efde-1523-785feabcd123)
   Characteristic User Description (0x2901)
- Unknown Characteristic [W] (0000b004-1212-efde-1523-785feabcd123)
SMP Service (8d53dc1d-1db7-4cd3-868b-8a527460aa84)
- SMP Characteristic [N WNR] (da2e7828-fbce-4e01-ae9e-261174997c48)
   Client Characteristic Configuration (0x2902)
D 11:37:49.264 gatt.setCharacteristicNotification(00002a05-0000-1000-8000-00805f9b34fb, true)
D 11:37:49.267 gatt.setCharacteristicNotification(0000b001-1212-efde-1523-785feabcd123, true)
RE: OTA zip upload issue.

Menon — Wed, 25 Mar 2026 09:55:05 GMT
Hello,
Which nRF device are you using here? Are you working with a DK or a custom board? Please share the SDK version as well.
I see that you have enabled logs via RTT. Could you share those as well? They might provide more details about the issue you are seeing. I also recommend enabling the MCUboot logs, as this may provide more details.
Does this happen only with the ZIP file? Have you tried using a .bin file instead? Also, what happens when you try using the Device Manager application?
Kind Regards,
Abhijith