Hereeeeee weeeeeeeeeeeeee go, the WRONGCO Hamper Helper
When you walk into the room, the Hamper Helper will let you know if the hamper is full and you need to wash clothes, by flashing a sign and an audible annoying beeper..
No worry, if the laundry is stinky, the Hamper Helper will give an aromatic squirt of air freshener so you can put off washing clothes as long as you want.
The first task of the hamper helper control system is to detect a person nearby to the Hamper. No need to waste battery power if no one there to tend to it. That will be done with a PIR and a relay to power the system up. This control section to be done later.
The second task task of the Hamper Helper control is to detect if there is a pile of clothes stacking high in the hamper.
This is where this blog begins.
I have an inventory of VS1838 IR receivers in hand. The VS1838s are not especially well suited for this purpose, but then again, it'd be no fun if the design didnt have some Rube Goldberg flavor to it.
The VS1838 needs a 38kHz IR carrier, and per the spec sheet, the pulse train for detect marks and spaces in at most a 600 us and 900 usecs (1500 msec period) respectively.
If those conditions are met, and if emitter and receiver are strategically placed, the IR receiver can see a pulse train from an IR LED emitter, and if it doesnt , that means the clothes in the Hamper are blocking the beam.
Rather than tie up an Arduino just for clock pulses, 555 timers were used.
One 555 cycles at 1.5ms period (1.5 4m s measured), and feeds the reset line of a second 555 timer running at 38kHz as the modulator (37.2kHz measured).
I am sad to say I couldnt get it to work reliably, but it did kind of work at times. Its not clear if the reliability is due to the 555 timings being slightly off, the 40% duty cycle is not quite there, or some other thing with the circuit or my setup. The emitter signal was aimed to bounce off the ceiling back down to the VS1838.
I've thrown in the towel on this approach and have ordered phototransistors for another crazy Rube-ish scheme to interface an "electric eye" beam detection to the Arduino.
The 1500 msec , 666.7 Hz pulse train
The resultant modulated signal to the IR emitter
Photographic proof the IR emitter is firing
I hope you enjoy the blog
