v0.3.0

Release Highlights

• Uses NCS v3.2.0 release.
• Added automatic data reception for sockets with AT#XRECVCFG.
• Added PPP shell sample for nRF54L15 and native_sim hosts.
• Removed TCP and UDP clients. Sockets and automatic data reception feature replace them.
• Removed support for nrf52840dk, nrf5340dk, nrf7002dk in the host samples.

What's Changed

• app: Use PDN ID Instead of CID for Socket Binding by @juhaylinen in #94
• doc: Fix #XGNSSDEL command description by @tokangas in #99
• app: Suppress POLLNVAL error when disconnecting from the MQTT broker by @juhaylinen in #100
• doc: app: Misc minor fixes by @trantanen in #97
• app: Update version generation cmake script by @juhaylinen in #98
• app: Remove fd_peer by @MarkusLassila in #104
• Manifest: Update nrf to v3.2.0-rc1 by @trantanen in #103
• app: Remove dependency to NCS PDN library by @juhaylinen in #91
• app: Update overlay file for memfault by @juhaylinen in #105
• doc: Improve nRF Cloud AT command documentation by @tokangas in #106
• samples: sm_at_client_shell: Remove nrf52840dk, nrf5340dk, nrf7002dk by @trantanen in #107
• samples: Add shell sample for PPP modem driver by @SeppoTakalo in #86
• app: Move small modules out of sub directories by @trantanen in #11
• doc: Updates to PPP shell sample by @divipillai in #109
• app: Add automatic data reception for sockets by @MarkusLassila in #102
• Manifest: Update nrf to v3.2.0-rc2 by @trantanen in #112
• github: workflows: build: Fix native_sim build for PPP shell sample by @trantanen in #110
• app: #XAPOLL parameter and functionality changes by @MarkusLassila in #114
• app: Fix datamode by @MarkusLassila in #116
• doc: Restructuring documentation by @trantanen in #113
• app: Remove TCP and UDP clients by @MarkusLassila in #115
• manifest: Update nrf to v3.2.0 by @trantanen in #118
• doc: Add UART configuration page by @SeppoTakalo in #117
• app: Socket option TLS_DTLS_FRAG_EXT by @trantanen in #108
• app: Fix echo with automatic reception and XAPOLL by @MarkusLassila in #119
• doc: Restructuring app doc by @trantanen in #121

New Contributors

• @tokangas made their first contribution in #99

Full Changelog: v0.2.0...v0.3.0

v0.2.0

Release Highlights

• DTR and Ring Indicator pins replace power and indicate pins.
• Refactoring of socket API. All commands now take a socket handle. Also adding support for hexadecimal sending and receiving.
• Changed default AT command terminator to CR.
• Optimized PPP/CMUX and Cellular Modem driver implementations to support proper power saving. A sample to be introduced in the next release.
• Added generated documentation.
• Removed support for nrf9160dk, nrf9161dk, nrf9131ek and thingy91 board targets.
• Removed the following features: Native TLS, TCP/UDP servers, HTTP client, FTP, GPIO, TWI/I2C

What's Changed

• app: PIPE interface to UART by @MarkusLassila in #6
• app: Remove use of minimal libc by @trantanen in #13
• DTR/RI UART by @MarkusLassila in #8
• github: Initial build workflow by @trantanen in #15
• doc: Initial version of migration guide by @trantanen in #14
• sm_host: Fix DTR/RI pin selection by @MarkusLassila in #16
• app: Rename AT#XGPS to AT#XGNSS by @juhaylinen in #7
• app: AT#XPOLL command removed by @trantanen in #17
• Fix DTR issues found in CI testing the ext mcu. by @MarkusLassila in #21
• manifest: update nrf by @trantanen in #19
• github: Fix nightly build workflow by @trantanen in #20
• doc: Add SM-addon documentation by @divipillai in #18
• sm_host_shell: Remove logging of data by @MarkusLassila in #22
• doc: Remove Kconfig links and reformat migration notes by @divipillai in #25
• doc: Add DTR/RI documentation by @MarkusLassila in #23
• doc: add zoomin workflows by @DematteisGiacomo in #27
• app: Update socket AT commands to use handle-based API by @juhaylinen in #26
• doc: Fixing Zoomin workflow + misc doc build fixes by @trantanen in #30
• app: Allow '_' in AT commands by @trantanen in #33
• manifest: Update NCS to v3.2.0-preview2 by @trantanen in #29
• treewide: Change AT command terminator to CR by @trantanen in #35
• app: New AT#XSEND and AT#XSENDTO command syntax by @juhaylinen in #31
• app: Don't start PPP without a request by @trantanen in #28
• app: New AT#XRECV and AT#XRECVFROM command syntax by @juhaylinen in #36
• app: Add echo for AT commands (ATE0/1) by @MarkusLassila in #32
• doc: Clarify need for */ns board targets by @mgolu in #39
• doc: Minor fixes to document headings by @divipillai in #41
• app: Remove support for nrf9160dk, nrf9161dk, nrf9131ek and thingy91 by @trantanen in #34
• app: Drop the interrupt support on UART by @SeppoTakalo in #42
• app: scripts: Try to recover CMUX if AT command fails by @SeppoTakalo in #45
• app: cmux: Drop URC when pipe is closed by @SeppoTakalo in #44
• app: Add HEX string support for AT-socket send and receive commands by @juhaylinen in #40
• app: Remove native TLS support by @MarkusLassila in #37
• app: Move to nRF sockets for socket AT-commands by @MarkusLassila in #47
• app: Replace poll thread for #XAPOLL with nRF callbacks by @MarkusLassila in #48
• app: Add data_len parameter to AT-socket receive commands by @juhaylinen in #50
• app: scripts: Stop PPPD before AT+CFUN=0 by @SeppoTakalo in #46
• Update nRF Connect SDK for CMUX changes by @SeppoTakalo in #53
• drivers: Fix event handling when stopping by @SeppoTakalo in #54
• app: uart: Fix potential race-condition by @SeppoTakalo in #55
• drivers: Send disabled event also when DTR is not asserted by @SeppoTakalo in #58
• workflow: Fix compliance to fail on Checkpatch warnings by @trantanen in #51
• app: Allow returning to AT command mode when CMUX is closed by @SeppoTakalo in #56
• app: ppp: Don't restart stopped PPP by @SeppoTakalo in #52
• app: Fix PPP start up by @SeppoTakalo in #63
• app: Add #XSENDNTF for when 8192 is set as flags by @MarkusLassila in #49
• app: Remove Zephyr modem driver specific Kconfigs by @SeppoTakalo in #57
• doc: app: Fix PPP examples by @SeppoTakalo in #61
• Change ri-gpios to active low by @MarkusLassila in #65
• samples: sm_host_shell: Add nrf54L15 DK by @MarkusLassila in #59
• samples: sm_host_shell: Fix the preliminary UART closure by @MarkusLassila in #67
• app: Add data_len parameter to AT-socket send commands by @juhaylinen in #64
• doc: Update AT socket command examples by @juhaylinen in #66
• lib: sm_host: Immediately timeout cmd when TX fails by @MarkusLassila in #69
• app: scripts: Try returning the UART to AT mode on failure by @SeppoTakalo in #68
• app: Remove TCP and UDP servers by @trantanen in #70
• app: Add CONFIG_SM_AT_ECHO_MAX_LEN to allow truncation of echo by @MarkusLassila in #72
• Remove #XFTP, #XTFPT, #XGPIO, #XTWI by @trantanen in #73
• app: Use sm_work_q instead of system work queue by @MarkusLassila in #74
• treewide: Small fixes for nRF54L15 DK by @trantanen in #75
• doc: Update README by @trantanen in #60
• App: Add CONFIG_SM_AT_BUF_SIZE to set the AT-command buffer size by @MarkusLassila in #77
• app: Fix a race condition when closing the pipe by @SeppoTakalo in #78
• app: scripts: Update PPP scripts to handle recovery by @SeppoTakalo in #79
• app: scripts: Wait for connection termination by @SeppoTakalo in #82
• manifest: Allow CI to override repositories by @SeppoTakalo in #81
• app: Remove Linux specific configuration overlays by @SeppoTakalo in #85
• app: Rename #XSLMVER to #XSMVER by @juhaylinen in #80
• github: workflow: Document build for PRs by @trantanen in #76
• app: List ATE0/1 in #XCLAC by @trantanen in #84
• app: Remove HTTP client by @trantanen in #87
• app: Remove AT_SO_TCP_SRV_SESSTIMEO by @trantanen in #88
• app: Fix #XBIND ignores CID of socket by @MarkusLassila in #92
• treewide: Rename sm_host to sm_at_client by @trantanen in #93
• treewide: Ignore error from UART RX already stopped by @MarkusLassila in #95
• app: Clarify error codes by @MarkusLassila in #89
• doc: More instructions to "Getting started" by @trantanen in #96

New Contributors

• @MarkusLassila made their first contribution in #6
• @juhaylinen made their first contribution in https://github.com/nrfconnect/ncs-serial-modem/pull/...

v0.1.0

The first draft release of the Serial Modem Add-On built on nRF Connect SDK snapshot taken on 25th Sep 2025.
The functionality and APIs of the Serial Modem are the same as in Serial LTE Modem from nRF Connect SDK v3.1.x. However, a lot of renaming has taken place.

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What's Changed

• Copy NCS SLM as a base by @trantanen in #1
• github: workflow: Add empty compliance and build workflows by @trantanen in #3
• treewide: SLM to SM renaming by @trantanen in #2
• Minor upmerge fixes by @trantanen in #5
• github: workflow: Content to compliance workflow by @trantanen in #4
• README: Initial info by @trantanen in #10
• manifest: Set sdk-nrf version for v0.1.0 release by @trantanen in #12

Full Changelog: https://github.com/nrfconnect/ncs-serial-modem/commits/v0.1.0