Here are useful links to resources and information on CANopen embedded programming in general but especially on STM32 microcontrollers.
CANopen Node project https://github.com/canopennode
CANopen Node code issues https://github.com/CANopenNode/CANopenNode/issues
CANopen stack on embedded devices https://github.com/embedded-office/canopen-stack
CANopen Node supported devices https://github.com/CANopenNode/CANopenNode/blob/master/doc/deviceSupport.md
CANopen Node on Linux https://github.com/CANopenNode/CANopenLinux
CANopen Node example code https://github.com/CANopenNode/CANopenNode/blob/v1.0/example/main.c
CANopen Node Tutorial and testing https://github.com/CANopenNode/CANopenDemo
CANopen Node port on STM32 https://github.com/w1ne/CANOpenNode-CubeMX-HAL
CANopen Node on STM32 https://github.com/CANopenNode/CanOpenSTM32
CANopen application layer poster https://www.can-cia.org/fileadmin/resources/documents/brochures/co_poster.pdf
CANopen for Python https://github.com/christiansandberg/canopen
CANopen NOde Object Distionary editor https://github.com/CANopenNode/CANopenEditor
CANopen quick reference sheet https://www.kollmorgen.com/sites/default/files/public_downloads/S300_S600_S700_CAN%20Protocol%20Quick%20Reference.pdf
CANopen for Python documentation https://canopen.readthedocs.io/en/latest/index.html
CANopen node documentation https://canopennode.github.io/CANopenSocket/index.html
CANopen node discussion on SourceForge (abandoned) https://sourceforge.net/p/canopennode/discussion/
CANopen PDO example https://github.com/CANopenNode/CANopenDemo/blob/master/tutorial/PDO.md
CANopen on Wikipedia https://en.wikipedia.org/wiki/CANopen
CANopen hands-on tutorial slides https://os.mbed.com/media/uploads/sam_grove/canopenhothandouts.pdf
CANopen Nanotec online manual https://en.nanotec.com/products/manual/PD4E_CANopen_EN/bus%2Fcan%2Fcan_stack.html
CANopen Node random project Microchip source code http://www.laukutikls.lv/sites/laukutikls.lv/files/raksti/20_pielikums_ronin.pdf
The Basic of CANopen white paper https://www.ni.com/en-us/innovations/white-papers/13/the-basics-of-canopen.html
CAN bit time calculator http://www.bittiming.can-wiki.info/
CANopen basic explanation on CANFestival basis (RUS) http://we.easyelectronics.ru/STM32/can-canopen-canfestival-stm32-chast-pervaya.html
CANopen practical explanation (RUS) https://i-flashdrive.ru/raznoe/canopen-protokol-obzor-protokola-canopen-arm.html#PDO
CANopen explanation (RUS) https://www.rlocman.ru/review/article.html?di=147763
CANopen explanation (RUS) https://www.rlocman.ru/review/article.html?di=147764
