* updated wifi_eventmon to store events in LUA_REGISTRYINDEX
* updated wifi_eventmon debug comments
* Updated wifi.c to remove c_free()
In wifi_ap_listclient(app/modules/wifi.c), c_free() was replaced with
wifi_softap_free_station_info()
* Removed unnecessary line of code from app/modules/wifi_eventmon.c
* pmsleep refactor
* Shortened swtmr disabled message
* Added swtimer debug module option to user_modules.h.
* Added comments to user_config.h.
* Fixed error in documentation for node.sleep()
* remove blank sntp.c that got added in during rebase onto dev(6218b92)
* Added #ifdefs around SWTIMER_REG_CB to prevent inclusion of disabled
code
Added `node.egc.meminfo()` to expose LVM usage (to make the regular
`node.egc.ON_MEM_LIMIT` option usable).
Extended the `node.egc.ON_MEM_LIMIT` option to also take negative limits,
in which case that's taken as a request to keep a certain amount of heap
available for non-Lua use.
ds18b20 decimals do not take into account the sign bit. Since the original calculation was not so readable, rewritten in readable way that also fixes the bug. Same code as PR against master.
Initial commit for
https://github.com/nodemcu/nodemcu-firmware/issues/2225 .
Replay patches from Espressif's repository at
https://github.com/espressif/ESP8266_NONOS_SDK between tags v2.1.0 and
v2.2.0:
0001-sync-from-ccca00f2.patch
Superseded by existing changes, but lines reordered in app/driver/key.c
to minimize divergences.
0002-sync-from-3f38ad5a.patch
Upstream files only
0003-Update-links.patch
Not meaningful to NodeMCU
0004-sync-from-01990ad0.patch
0005-sync-from-cdf6877d.patch
Upstream files only
0006-sync-from-f29e744c.patch
Upstream files only, user_interface.h override non-conflicting
0009-feat-lwip-Move-lwip-source-code-to-third_party-folde.patch
Merged change to lwip/app/espconn_udp.c; rest is just moves or
appears to not apply.
0010-feat-mbedtls-Add-mbedtls-source-code-in-third_party-.patch
Does not apply; we use our own mbedtls
0011-added-C-support.patch
Merged to Makefile
0012-feat-mbedtls-Rebuild-libmbedtls.patch
Already applied
0013-fix-at-Fix-some-bugs-of-AT.patch
Upstream files only
0014-feat-err_t-Redefine-err_t-to-s32_t.patch
Merged to app/include/arch/cc.h and ./app/include/lwip/app/espconn.h;
the rest is upstream files.
0015-fix-wpa-Fix-wpa-wpa2-ptk-gtk-reinstallation-vulnerab.patch
0016-fix-wifi-Remove-group-key-entry-before-connecting-to.patch
0017-feat-lib-Remove-time-function-in-libmain.patch
Upstream files only
0018-feat-espconn-Modification-for-espconn.patch
Merged to app/include/lwip/app/espconn.h,
app/include/lwip/app/espconn_tcp.h, app/lwip/app/espconn.c,
app/lwip/app/espconn_tcp.c
0019-feat-at-Use-new-espconn_recv-to-fix-tcp-server-issue.patch
0020-feat-examples-Update-mqtt-demo-and-auto-bin-generate.patch
Upstream files only
0021-wifi-Add-scan-threshold-and-dwell-time.patch
0022-feat-wifi-Add-country-code-API.patch
0023-feat-wifi-Record-more-information-of-scanned-ap.patch
Upstream files only, user_interface.h override non-conflicting
0024-fix-example-Fix-IoT_Demo-user-sector-error.patch
Upstream files only
0025-fix-lwip-Fix-sequence-number-error-of-RST-ACK.patch
Merged app/lwip/core/tcp_in.c
0026-fix-mbedtls-Fix-memory-leak.patch
Merged app/mbedtls/app/lwIPSocket.c
0027-fix-mbedtls-Fix-call-send-callback-function-failed.patch
Merged app/mbedtls/app/espconn_mbedtls.c
0028-feat-Add-USE_OPTIMIZE_PRINTF-in-third_party-Makefile.patch
Merged app/Makefile
0029-fix-api-Fix-ets_delay_us-declaration.patch
Upstream files only, osapi.h override non-conflicting
0030-fix-wifi-Remove-max_tx_power-in-wifi_country_t-in-li.patch
0031-fix-wifi-Fix-softAP-wrong-behavior-after-call-system.patch
0032-fix-wifi-bugfix-of-scan-fail-after-connected-if-max-.patch
0033-feat-at-Enable-scan-time-scan-type-and-add-scan-resu.patch
0034-feat-at-Add-command-AT-CWCOUNTRY.patch
0035-fix-at-Fix-that-AT-CIPSTART-causes-busy-if-the-serve.patch
Upstream files only
0036-feat-mbedtls-Speed-up-mbedtls-handshake-process.patch
Merged app/mbedtls/app/espconn_mbedtls.c
0037-fix-api-Fix-os_calloc-declaration.patch
Merged app/include/lwip/mem.h; sdk-overrides/include/mem.h
non-conflicting.
0038-fix-mbedtls-Fix-disconnect-callback-function-never-b.patch
Merged app/mbedtls/app/espconn_mbedtls.c; minor revision to logic in
6576af959b. Whitespace fixes.
0039-feat-at-Add-country-code-start-channel-in-AT-CWCOUNT.patch
0040-fix-net80211-Fix-Null-pointer-in-ieee80211_rfid_locp.patch
Upstream files only
0041-feat-wifi-Add-new-esp_init_data_default-v08-bin.patch
Upstream files only, but impacts Makefile
0042-fix-mbedtls-Fix-load-cert-fail-when-the-private-key-.patch
Merged app/mbedtls/app/espconn_mbedtls.c
0043-fix-wifi-The-start-channel-can-be-any-valid-channel.patch
0044-fix-wifi-Fix-scan-do-not-start-after-connect.patch
0045-feat-wifi-Add-keep-connection-for-station-to-keep-co.patch
0046-feat-at-Update-AT-version-to-1.6.0.0.patch
0047-fix-at-Fix-GSLP-too-long-time.patch
0048-fix-at-Fix-the-message-is-incorrect-when-creating-UD.patch
0049-feat-at-Add-AT-CIPSERVERMAXCONN.patch
Upstream files only
0050-feat-system-Add-softap-distributes-station-ip-event.patch
Upstream files only, user_interface.h override non-conflicting
0051-feat-example-Use-libmbedtls.a-instead-of-libssl.a-in.patch
Upstream files only
0052-feat-mesh-Remove-mesh-support.patch
Upstream files only, but go ahead and remove comment from
ld/nodemcu.ld.
0053-fix-example-Fix-forget-to-add-integer-parameter-when.patch
Upstream files only
0054-fix-mbedtls-Fix-reconnect_callback-is-not-triggered-.patch
Merged app/mbedtls/app/espconn_mbedtls.c
0055-feat-at-Add-AT-SYSMSG-to-enable-some-report-informat.patch
0056-fix-at-Fix-the-incorrect-link-id-when-client-connect.patch
0057-fix-at-Fix-the-bug-that-it-should-be-error-when-the-.patch
0058-fix-smartconfig-Fix-the-smartconfig-scan-time-issue.patch
0059-fix-lwip-Fix-the-bug-of-lwip-output.patch
Upstream files only
0060-fix-lwip-Fix-the-length-of-TCP-data-in-one-packet-is.patch
0061-fix-lwip-Fix-send-TCP-data-with-two-or-more-pbuf.patch
Merged app/lwip/core/tcp_out.c
0062-fix-wifi-Fix-assert-happen-when-smartconfig-start-th.patch
Upstream files only
0063-fix-mbedtls-Fix-memory-leak-when-ESP8266-as-SSL-TLS-.patch
Merged app/mbedtls/app/espconn_mbedtls.c
0064-fix-mbedtls-Fix-already-freed-and-exception-bug-when.patch
Merged app/mbedtls/app/lwIPSocket.c
0065-fix-at-Fix-bug-that-there-is-no-result-when-sending-.patch
0066-feat-example-Add-AT-bin-version.patch
0067-feat-version-Update-version-to-2.2.0-and-add-version.patch
0068-feat-bin-Update-AT-bin-for-SDK-2.2.0.patch
Upstream files only
Apply local changes to build:
app/include/lwip/app/espconn.h pulls changes (and license decl) from
upstream SDK. Makefile is altered to use this file ahead of the
SDK's.
Remove lwip's sntp support, since it was never really wired in anyway.
See https://github.com/nodemcu/nodemcu-firmware/issues/2042 for more
information. Patch Makefile to strip time.o, the consumer of lwip's
sntp functionality, from libmain.a, resulting in much
easier-to-understand error messages.
This has consequences for mbedtls. The simplest thing to do, which is,
impressively, not a change in behavior, is to completely disable TLS
certificate time validation; a later patch can optionally couple this to
RTCTIME support.
Similarly, it happens that the sqlite3 import was calling time(), but
this was not going to work out well for it. Just stub it out to always
return unix timestamp 0, as would have happened anyway.
Changes unprocessed:
0007-sync-from-080c37e1.patch
0008-feat-lib-Compile-some-libraries-with-ffunction-secti.patch
These two make changes to the linker script; perhaps
they are worth porting over, but I have not done so
here.
This is build-tested (ADC, BIT, COLOR_UTILS, CRON, CRYPTO, DHT, ENCODER,
FILE, GPIO, HTTP, I2C, MQTT, NET, NODE, OW, PCM, PERF, PWM, RTCFIFO,
RTCMEM, RTCTIME, SNTP, SPI, SQLITE3, STRUCT, TLS, TMR, UART, WIFI,
WS2812, WS2812_EFFECTS) and boots, but only limited run-time testing has
been performed. Testing done does, however, include having made a few
TLS connections through the HTTP module, so things are not hopelessly
broken, at the very least.
* mbedtls 2.7.0 (mbedtls-2.7.0-0-g32605dc8)
Wholesale import, with a few changes from earlier preserved through.
Ideally we would soon get to the point of having no divergences from
upstream.
* tls: add function to adjust mbedTLS debug level
* Fix some subtle timing issues with gpio.pulse
* Add the pulse:update method
* Allow getstate to work on stopped pulsers
* Make gpio.mode(, gpio.OUTPUT) actually set the output mode
* Added some more documentation
Disable the error callback of mqtt.client:connect() after a successful connection.
This will prevent this function to be called after a future disconnection.
Instead the "offline" function is called.
in float build, uV and sign are included in mV
in int build, uV and mV are absolute, sign is -1, 0, 1
added rounding of uV values
added optional test function
* ads1015 is supported, up to 4 devices can be connected at the same time
* removed debug, updated documentation
* changed to oop API
* added __gc to handle active timer cleanup
* reworked argument validation and error reporting
* stack is no longer messed up after __del
* ws2812 effects and color utils modules added
* Added documentation for new modules to mkdocs.yml
* changed mode option to string, documentation, default modules fixed
* updated user_modules.h
* add final sqlite3 patch
* remove unused defines, join caching code with esp vfs code to reduce exported symbols and shrink final file size
* Modules should by default be disabled and in alphabetical order
* Add support of counting of interrupts
* Update the timestamp when interrupt happens during dispatch. Also
clear out interrupts when setting up a new callback
That file is supposed to only be included once because it does things
like declare static globals. As it stands, cron doesn't believe time is
ticking.
Fixes#2080
* Improve RTC timekeeping -- includes clock rate tracking
* Improved division by 1M
* Fix crash in sntp
* Disable RTC debug
* Get the offset correct
* Add comments on where the mysterious numbers came from
* Fix a crash with auto repeat mode and errors on repeat
- Move jsonsl build to regular library build rather than #include the .c file
- Provide wrappers for malloc/calloc/free to fix undefined symbol warnings.
* Add event callbacks to wifi.sta.config() and wifi.ap.config() and more
Added option to register event callbacks during configuration of both
station and AP.
Added option to register event callbacks to `wifi.sta.connect()` and
`wifi.sta.disconnect()`
* Add note about event registration to wifi module documentation
Other minor changes to wifi documentation are also included
* Add more detail to documentation for wifi.sta.config()
The following functions were removed:
- `wifi.sta.eventMonReg()`
- `wifi.sta.eventMonStart()`
- `wifi.sta.eventMonStop()`
The corresponding documentation has also been removed
This PR addresses issue #1893
Documentation for the old(argument) style of station configuration was
removed in a previous PR, so I added a deprecation message to inform
developer of the upcoming removal of the feature.
* Fix the error callback from not being called sometimes
* Moved the setting of the reconnect status to after the connack is recevied
* Increase the irom0_seg size
* Updated the documentation
* Make it clearer that autoreconnect is deprecated
* Update wifi event monitor documentation
Added a note to `wifi.eventmon.register()` and `wifi.sta.eventmonreg()`
* Add deprecation note to `wifi.sta.eventMonReg()`
* Add wifi.sta.clearconfig(). Adjust password validation to match 2.0.0 SDK rules (no min length enforced, i.e. for WEP)
* Updat comments about WEP key not having a minimum
* Documentation: add note about node.restore() to wifi.sta.clearconfig() docs, and add SDK verbiage to describe what node.restore() impacts.
* Normaliz if statements
* Convert leading tabs to leading spaces for consistency
* Fix bug in sntp where callback was run at interrupt level. Also add
the nodemcu pool servers as the default.
* Add comments on where the mysterious numbers came from
* Fix a crash with auto repeat mode and errors on repeat
* Rewrite net.dns.resolve on LWIP
* Move IGMP (net multicast) to LWIP
* Cleanup net module
* Move secure connection operations to tls module
* Net module on LWIP
* Server timeout parameter
* TCP hold
* Fixes in documentation
* Documentation fixes
* Note TLS module depends on net
* Add TLS module to user_modules.h
* Callback on connect event
* Fix depends net module on tls module
* Fix unhold exponential time issue
* Check the return code of the read function when doing crypto.fhash so that we don't pass negative lengths to the hashing functions
* Fix various assert failures in the LVM arising from rotables. No functional change
* Add the gpio interrupt time to the callback (and pass it from the interrupt handler)
* Get the PC right in the perf module
* Make the headers static in the websocket module
* Fix the documentation
* Switch off interrupts before rtctime dsleep.
* Deal with the fact that MCU keeps running after being told to enter deep sleep
(It can keep running for quite a few instructions at times (and none at
all at others), and it appears that trying to cache additional code from
SPI flash while trying to go to sleep fails miserably at both....)
* Ensure flash is not active when going into deep sleep.
- Bug fixes and improvements
- FIX: Ensure that station is enabled before doing network scan (this seems to be the cause of #1578)
- FIX: Check if state == NULL on enduser_setup.stop()
- IMPROVEMENT: Look for both enduser_setup.html.gz and enduser_setup.html as valid filenames, for semantic reasons
- IMPROVEMENT: Show a generic status message on HTML page if failure occurred before user even submitted data (i.e., would have come from previously stored config when the STA was started by EUS)
Looks good to me. Thank you.
Also:
- allow for '\0's in received messages
* add client:config for setting websocket headers
Also:
- headers are case-insensitive now
* fix docs
* fix typo
* remove unnecessary luaL_argcheck calls
* replace os_sprintf with simple string copy
Squashed commits included:
Bug fixes and final implementation
- Added Content-Length: 0 to all headers
- Endpoint name checks not using trailing space so cache-busting techniques can be used (i.e., append a nonce to the URL)
- Track when connecting so APList scan doesn't take place during (which changes the channel)
- More debugging output added to assist in tracking down some issues
Added /status.json endpoint for phone apps/XHR to get JSON response
Station Status caching for wifi channel workaround + AJAX/CORS
- During checkstation poll, cache the last station status
- Shut down the station if status = 2,3,4 and channel is different than SoftAP
- Add Access-Control-Allow-Origin: * to endpoint responses used by a service
- Add a /setwifi GET endpoint for phone apps/XHR to use (same parameters as /update endpoint). Returns a JSON response containing chip id and status code.
- Add handler for OPTIONS verb (needed for CORS support)
Wi-Fi Channel Issue Workaround
- Do a site survey upon startup, set SoftAP channel to the strongest rssi's channel
- Compare successful station connect channel to SoftAP's. If different, then defer the Lua success callback to the end. Shut down Station and start the SoftAP back up with original channel.
- After the 10 second shutdown timer fires, check to see if success callback was already called. If not, then call it while starting the Station back up.
HTTP Response and DNS enhancements
- If DNS's UDP buffer fills up, keep going as non-fatal. It's UDP and not guaranteed anyways. I've seen this occur when connecting a PC to the SoftAP and every open program tries to phone home at the same time, overwhelming the EUS DNS server.
- Support for detecting/handling pre-gzipped `enduser_setup.html` (and `http_html_backup`) payload. Nice for keeping the size of the `state->http_payload_data` as small as possible (also makes minimization not as critical)
- Corrected misuse of HTTP 401 response status (changed one occurrence to 400/Bad Request, and changed another to 405/Method Not Allowed)
* Normalized formatting (tabs-to-spaces)
* Added documentation
* Corrected misuse of strlen for binary (gzip) data.
* Added NULL check after malloc
* Removed inline documentation for several functions and update comments
Since documentation is now part of the repository, the inline
documentation just adds to the already huge wifi.c
* Wifi module: add new functionality, update documentation
Functions Added:
wifi.getdefaultmode(): returns default wifi opmode
wifi.sta.apchange(): select alternate cached AP
wifi.sta.apinfo(): get cached AP list
wifi.sta.aplimit(): set cached AP limit
wifi.sta.getapindex(): get index of currently configured AP
wifi.sta.getdefaultconfig(): get default station configuration
wifi.ap.getdefaultconfig(): get default AP configuration
functions modified:
wifi.setmode: saving mode to flash is now optional
wifi.sta.config: now accepts table as an argument and save config to
flash is now optional
wifi.sta.getconfig: added option to return table
wifi.ap.config: save config to flash is now optional
wifi.ap.getconfig: added option to return table
Documentation changes:
- Modified documentation to reflect above changes
- Removed unnecessary inline documentation from `wifi.c`
- Updated documentation for `wifi.sta.disconnect`to address issue #1480
- Fixed inaccurate documentation for function `wifi.sleeptype`
- Added more details to `wifi.nullmodesleep()`
* Move function `wifi.sleeptype()` to `wifi.sta.sleeptype()`
* Fixed problem where wifi.x.getconfig() returned invalid strings when
ssid or password were set to maximum length.
* fix error in documentation for `wifi.sta.getapindex`
* Renamed some wifi functions
wifi.sta.apinfo -> getapinfo
wifi.sta.aplimit -> setaplimit
wifi.sta.apchange -> changeap
also organized the wifi_station_map array
* Add load/dump/mix/power operations on the buffer object
* Calculate the pixel value in mix and then clip to the range.
* Fixed the two wrong userdata types
* Added a couple more useful methods
* Add support for shifting a piece of the buffer.
* Fix a minor bug with offset shifts
* remove luaL_buffer from file_g_read()
- avoid memory leak when function gets terminated by lua_error
- skip scanning for end_char when reading until EOF
* attempt to free memory in any case
* Initial version of gdbstub support
* Add DEBUG argument to Makefile to add more debug data and turn off -Os
* Add the output redirection handling
* Added documentation
* Cleaned up the english a bit
* Make gdboutput actually trap all the output
* Review comments
* Add FatFs
* enable BUILD_FATFS for all-module build
* push vfs into rest of firmware
* align maximum filename length
* increase timeout for acmd41 during card initialization
* switch from DOS to Unix path semantics chdrive() is substituted by chdir()
* update to fatfs R.012a incl. patches 1-6
* add callback for rtc provisioning in file
* update docs
* added fadeIn, faceOut and shift to ws2812 module
* improvements to rotate, unified fade method
shift renamed to rotate and usage of more efficient memory operations.
fadeIn and fadeOut unified into fade method with optional parameter for direction.
* rename method to "shift" with optional mode parameter
Fixes#1164 and thus also #1150, #1149, #1147 and #898.
* Move to latest version of SPIFFS
* Add SPIFFS porting layer for NodeMCU
* Add option to delete output if it doesn't fit
* Change FLASHSIZE to be in bits by default: default 4mb 32mb
* Add SPIFFS_MAX_FILESYSTEM_SIZE override
* Add notes on SPIFFS_FIXED_LOCATION
* Add 1M boundary
* Include the current version of the LICENSE
- Stop fighting against the SDK in terms of owning/writing the init_data block.
NodeMCU included a default init_data block because originally the SDK did
not, but by now it's not needed.
- Expose a way to reconfigure the ADC mode from Lua land. With most people
using the cloud builder and not able to change the #define for byte 107
this has been a pain point.
- Less confusion about which init_data has been used. Lua code can now simply
state what mode it wants the ADC to be in, and not worry about the rest of
the init_data complexities such as the init_data changing location due to
flashing with wrong flash_size setting, or doing/not doing a chip-erase
before loading new NodeMCU firmware.
* Change upper limit for timer in `tmr_register` and `tmr_interval` to reflect new limit in SDK 1.5.3.
* Change documentation for `tmr.alarm()`, `tmr.interval()` and `tmr.register()` to match source.
* Improve error reporting to be more descriptive.
* Fix bug on first write
Pin is 'HIGH' at reset, so we need to pull it down and generate a
reset.
* Move init code to flash section, not needed to be in iram.
* Remove pin choice in API
* Remove lock in ws2812_buffer_write
* Remove naked malloc
* Drop ws2812_writergb
* Drop support of ws2812.buffers to ws2812_writegrb should use ws2812.buffers:write
* Add support for <>3 colors per leds strips (RGBW)
* Remove ICACHE_FLASH_ATTR
* Add static const on _uartData to avoid initialization penalty
* Provide an error code to SNTP error callback.
* Switch SNTP to use ephemeral port.
In case we're being hit by ISP-level thou-shall-not-run-NTP silliness.
Merging as suggested by @TerryE (and squashing at the same time. Turns out that this feature is enabled for this repo).
* Squashed commit of the following:
commit f985f10d9d2ee035f5a6ee6245c60d9904d98cc1
Author: philip <philip@gladstonefamily.net>
Date: Sun Mar 27 21:52:46 2016 -0400
Better mdns code
commit 6ee49ee106
Author: philip <philip@gladstonefamily.net>
Date: Fri Mar 25 23:25:11 2016 -0400
Update the docs
commit 7e455541c6
Author: philip <philip@gladstonefamily.net>
Date: Thu Mar 24 21:58:16 2016 -0400
Add retries and buffer checking to mdns
Get the length right
Now it seems to work
* Might work for combined mode
* Fix crash
* Simplified various bits of code. Changed the LUA interface
Added checking (to some degree) incoming quyery types
Move the defaults to the right place
Added reference to the RFC`
Implement SDK event monitor
Move wifi status event monitor code into seperate file
(app/modules/wifi_eventmon.c)
Modify wifi lua callback registration code.
Add Functions wifi.ap.deauth and wifi.sta.getrssi
Rework wifi event monitor to use tasking interface
fix for Lua coroutine compatibility issue
Made changes Suggested by TerryE
Also, moved code that sets the default host name out of
luaopen_wifi_init and into a separate function and added a post_task_low
entry in it's place.
Replaced some if test then return error lines with
luaL_argcheck
Add check for malloc null return in wifi.eventmon
to catch out of memory errors
Due to the hard-close, the status message did not get sent out reliably.
Connection closing logic now reworked to be nicer, while still avoiding
the problem of lots of connections lingering in fin_wait.
Shutting down an espconn server safely is impossible, and currently would
include at least one use-after-free. Even with that patched, at best this
would change things from impossible to "very tricky".
The native LWIP API does not have those issues, and is still quite easy
to work with.
A single bug is fixed, a few features are added and overall the codebase has been worked through.
- Added support for calls to /generate_204 that let's android know that the internet is accessible.
- Added 10 second delay to the shutdown call to allow a final status update to be fetched by the client.
- Added iframe to html to avoid having a form submission change the page.
- Added support for dynamic /status responses.
- Improved HTML appearance by removing AP-list button.
- Improved CSS to center form, even when list of access points have loaded.
- Improved debug prints to contain line numbers and not require lua_State*.
- Fixed broken failure check when calling wifi_station_connect().
- Fixed unguarded malloc().
TerryE
Arnim Läuger
dnc40085
dnc40085
philip
Johny Mattsson
petur
Philip Gladstone
Nathaniel Wesley Filardo
Nathaniel Wesley Filardo
Frank Exoo
Pawel Jasinski
Konrad Hübner
Luiz Felipe Silva
Carlos Bastos Filho
Lukáš Voborský
Mark Deneen
Suraj151
fetchbot
Johny Mattsson
Metin KOC
tjhowse
Marcel Stör
Yury Popov
Jason Follas
ffedoroff
kicer
Mariusz Kryński
Luís Fonseca
Thomas Soëte
Jason Schmidlapp
Sebastian
Robert Foss
Robert Foss
Marcel Stör
Bernd Meyer