I came across an interesting website today while attempting to track down some information on some Modbus modules I'm ordering. Shenzhen LC Technology Company is the home of many of the Chinese modules you find on ebay, Banggood and AliExpress. And the site has clear, detailed documentation in many cases.
If you're contemplating ordering some type of module, you might start here first to see what's available and if the documentation is sufficient for your needs. If you see something you like, search for that module from the usual sources.
If you're contemplating ordering some type of module, you might start here first to see what's available and if the documentation is sufficient for your needs. If you see something you like, search for that module from the usual sources.