Stepping back and looking at the big picture is always a good idea. What do those failed projects have in common? From my perspective, your projects seem to suffer from on the fly engineering (little planning), feature creep, and a whole lot of do-everything-at-once with little testing/prototyping. I would suggest planning - draw out what you want the final product to be, then break the task/project up into discrete "chunks" that can built, tested, etc., before moving on. Focus on the basic stuff first. You can add the bells and whistles later. If you have a solid plan, breaking it into manageable parts can make an overwhelming project doable. Have measurable milestones. Use what you know works from other projects. Document everything - successes AND failures, so you have a knowledge base to draw on. Don't rush to fail. Take breaks if you're stumped, work on something else and then come back to it. At least, that's what works for me...
IT might not be that hard with the Arduino.. Don't need Mega as the I/O uses 12 pins and a garden variety UNO has 14 digital and 6 Analog ! So maybe I will scrap the 4011 logic box and design and Aduino substitue!! Thats what doesn't work in the system: the 1980s designn of the LOGIC unit. I can replace the box with a UNO and a LCD. STAY TUNED!
Why not get it working with switches, as you said? Get the RF stuff working under manual control before you invest in another attempt. Once you have that, then you can automate in modules, instead of all at once.
I designed the switch box version: 2 toggle switches, 1 eight position rotary switch and one pushbutton switch (oh and one 14 pin dip socket.
and the guts Still need to wire it up. but it is a Direct substitute for the BLACK BOX LOGIC BOX! Of course there are NO ICs, NO RELAYS, NO RATS NEST OF WIRES, just a simple circuit that is absolutely Bullet proof! This will have to do until I get the Arduino version designed!
A little extra, yes. But, 2100 uF divided by 6 is 350 uF. Even with a "soft start", the charging surge will be impressive. More important, any HV fault will result in a truly impressive fault current. Better stock up on glitch resistors and meter protection diodes.