Unfortunately buck, boost, and boost buck mode controllers don't series very well. The ground is common from in to out and will short the output if connected in series with a common supply for the input voltage. If you need greater output voltage then there is a pot to adjust the output keep in mind several things.... The input voltage must typically be 2 volts greater than the output for a buck mode converter.... If you have questions I will try but the data sheet and a little common sense should answer the bulk of your issues.
The devices can get hot so make provisions for that and ALL devices can fail and only a FOOL doesn't take that into account and a BIGGER fool is the one who takes no precautions whatso ever
This was the main reason I suggested using several devices and split the loads up Between the devices...
There was one poster that claimed that the devices fail with over current... I suggest he hasn't a concept of how to use them and I still think i will keep my keyboard quiet.
I am tired of spending time that I could use to do my own work trying to help people who know it all and are apparently just trolling for someone to take on someone...
To try to "Help" someone who can't read the free information provided hare is unforgivable and the Last Expert who shared his ineptitude was the final straw.
To take a switcher and load it to the max without reading the relevant information on the website that sold it to him (free too) is frankly unbelievable. To wire the Arduino to the same power supply as a High Current load is it's own just desserts and to do so with anything but a star ground system is not the smartest either... one ground fails and suddenly... You think Crosstalk...
There are quite enough engineers of good ability and knowledge (or at least there are enough to try to tell me that I have no idea of what I am saying) here to more than Ably take my place.
This whole endeavor is too time consuming for the occaisonal thank you.
The only thing I can figure out is that my knowledge is just out of date and rather than have some "Expert" try to tell me that what works for me is no good and will damage someones project is beyond me. If you or anyone here wants my opinion... PM me. I am here to advise people with what I know and now it's tine for the REAL experts to take up where I am happily leaving off.
Unlike the Experts I WILL back up what I advise and I TEST anything I advise and anything I advise was something that worked over the 40 year period I was actively in this business or is something I am doing today. I am old and tired and quite tired of trying to make a difference here. There is always some sophomore engineer who knows more about everthing except how to keep his mouth shut.
Robert Khayyam Sr