(PG21 onward)

Very informative and super helpful to have all of the specifications and sample files in one document. This is really taking shape.
I have a few suggestions:
---On the hardware side you are getting really indepth and this is helpful to those who may already have some arduino experience but are now interested to try uiflow. However the code examples you are using for the units are more for beginners and I think starting off the book with some very basic code concepts like setup, loops, delay, etc would really help support those samples. At the same time you also might want to have some examples of more complex code to show those experienced users just how capable uiflow can be.
--- I really like that you describe i2c, digital, analog, and uart units. I think it would be great to have an visual index of all units and divide it up, like the periodic table, according to those categories and then have a chapter on each of the 4 types.
-- Start off the unit chapter by showing how a unit is selected and loaded into uiflow and how it adds new blocks according to the selection. This goes over the general workflow of using a unit. I think this can help prevent you from having to explain how to load each specific unit and focus in on what the unit does.

Thank you for taking the time to read through and give feed back.
This is why I'm sharing the WIP's so that I can improve the work.
The code samples are designed to be basic in the first few chapters.
Chapters 4, 5 and 6 are designed to be slightly more in depth and chapters 7 and 8 designed to be advanced projects.
There is also a Contributors section that contains members projects.
The periodic table of parts is an interesting idea and something I want to do but fitting it in the book is difficult. I will work on the idea and release it as an additional file Maybe an A3 poster that can be brought.
Covering the hardware side of the core and stick units is a bit of a rabbit hole as the datasheets on the components are nearly 500 pages of information and tables (a growing list of these datasheets has beed added to the back of the book.

Thank you again and if you have any more idea's please let me know.

Another update - http://www.ajb2k3.co.uk/UIFlowhandbook.pdf

still trying to work out how to build a MQTT broker.

Thanks, that are a few graphical issues to sort out but the base is getting there.
It's formatted to be printed at A4 for "Finger" binding.
Any ideas or requests?
I'm just trying to get an MQTT broker running to test the new MQTT functions.