A smart controller for a powered chair or bed

Wow. That sounds morbid, doesn't it? How about "The project is nearly finished'?

I worked out the remaining software glitches, so now the device's operation is nearly flawless!

I am not necessarily tooting my own horn since I really use it (the chair, not the horn).

The long-awaited video will be coming as soon as I convince my wife to show-off her modeling abilities. Trust me, you do not want ME to demonstrate it!!

The Pin.PULL_UP settings are now Pin.PULL_DOWN, and not really needed.

 Why?

Because by default, the controller (button) contacts are normally-closed to ground, thus eliminating the need of a PULL_DOWN resistor. The normally-open side is +5VDC.

Yeah but...

 There is always a caveat: The above reigns true IF a controller is plugged in. If not, the inputs will "float" in an incalculable state. That would be bad, am I right? (The answer is yes)

The bottom line: 

PICO's internal Pin.PULL_DOWN setting will work just fine for unconnected controllers.

I came across some hindrances when moving from the "Proof of Concept" to "Prototype" stage.

Or better said, from the “plastic case” to an “aluminum case” stage.

Aluminum is a conductor, plastic is not.

Consequently, well, you get it.

Enough said.

Oh, and by the way, the 5-pin DIN connector, when used for a factory powered chair/recliner/bed (and unlike its shared MIDI use), the case is very-much used. If you read any of my previous logs, in hindsight this is precisely why I fried my original Raspberry PI.

Why didn't I learn?

I'm almost a month early getting version 2 (the prototype) built. Videos of it in operation will be added within the week.

Making progress..,.

Next: Driling holes in the end-panels (16 of 'em)

At this point, I’m moving the project out of my ugly ‘proof of concept’ stage and into the prototype stage. This new stage boasts a modern design with its appearance looking much more professional. 

For the hardware, the current grey plastic case that looks so horrible is being replaced with a smaller, black anodized aluminum case with chromed LED holders, and an external USB connector. 

Software improvements include allowing better control, self-learning timing, and much more.

The new prototype version is currently being developed, and I’ll be posting pictures as milestones are reached. Remember, I’m the sole person doing every aspect of hardware development, software updates, testing, and documentation. So please be patient with me! My goal is to have the prototype completed by 6/30/2023. 

It turns out the PICO's internal pull-up/pull-down resistors are somewhat undependable/unpredictable  for anything but unconnected GPIO pins, as expained at https://forums.raspberrypi.com/viewtopic.php?f=144&t=315020

I'm adding external resistors, plus a secret surprise!!

The Raspberry PICO HW works out fine. By adding a 2-channel relay board, which is optically connect and directly controlled, the unit makes sense. Although the OS switch from Python to microPython had a learning curve, it was small. 

Oh, the HW... 

H = pre-soldered header pins

W = WiFi included

...and only $15? Heck yeah

After kicking myself for blowing up the PI  and wallowing in self-pity, I did a little research, eventually running across the Raspberry PICO. Cheap, small... it's perfect for this application. It also actually revealed to me that the Raspberry PI was way overkill for this anyway!

That, or maybe I'm just trying to justify trashing my PI? 

No, it's not that since my verty thoughtful son-in-law Justin bought it for me a a gift. 

Yeah, now I feel like sh*t.

It turns out, if you shove 24vcd down one of Raspberry PI 's GPIO pins, it pretty much trashes it, making it unrecoverable. In short, throw it away.