DollaTek 5Pcs Rotary Encoder Module Rotating Potentiometer Knob Cap Digital Control Module

This is an interesting device which needs playing with.Unfortunately, as with most Chinese devices, it comes with no paperwork nor identifying marks on the part. This means that it can not be verified. The sales description is vague about whether it is a mechanical (mechanical switched quadrature signal) device or an optical (the detection of the quadrature signal signal is developed via an optical means). The description alludes to it being an optical device, which is what I was looking for to avoid contact bounce. I haven't put it on an oscilloscope yet to determine whether it has contact bounce... yet. Without any physical markings on either the board (other than silk screened pin outs) any actual documentation can not be found on the web. I might suggest doing a destructive (physically disassembling the switch) to verify whether the switch meets specifications. It does come with the knob, shaft nut and washer for mounting the unit (a plus), but again, without documentation, it's hard to determine any physicals (especially for drilling holes for mounting). It does include a center push switch which is a short throw and reasonably robust enough to not accidentally push and cause contact, a plus. The silkscreen markings are good, but awkward to determine. I wish that the manufacturer would have put the power pins together rather than on opposite ends of the header (a minor ding), protecting against inverting the power/data connector and possibly causing damage to the unit or microprocessor. Because of this flaw, I might suggest isolating the board with a Quadrature decoder or at least an opto-isolator or some other discrete device to isolate the device from the microprocessor (an added and really unnecessary expense) . Or maybe taking up a little more space on the board by placing an open pin as a key. The quadrature signals are clearly marked on the silkscreen with "S1" and "S2", and the push button switch with "key" on both sides of the PC board. (A Plus) On the other hand I'd prefer that the silk screen legends would have used the standard markings of "A", "B" and "SW" or some other indicator than "Key". This piece, on the surface, looks to be a good, inexpensive unit, for playing with as an optical quadrature switch. I wouldn't let the detractors I listed, other than the lack of documentation, deter one from playing with the unit. As a part in a marketable device... the biggest detractors are the power/data header from a repair/replacement stand point as mentioned earlier, the lack of manufacturer part numbers on the switch, and serious lack of documentation. I'm still playing with the unit, and update this review at a later date.

These are mechanical rotary encoders, with a light clicking action. They include resistor/capacitor/resistor debounce circuitry on the pcb which helps tremendously. Pinout is on the pcb: GND (0V), Key (Switch), S1 & S2 (rotary encoder), 5V (or 3.3V). Note that the voltage is more to do with the debounce circuit than the component rating.Closest schematic for the debounce circuit I can find is attached.Push switch is connected between Gnd and the Key terminal.There is a fair bit of white powdery flux residue on the boards - easily cleaned off with isopropanol.Supplied with washers and nuts, and push-on splined knobs.

le flux de soudure n'as même pas été nettoyé !livré avec rondelles et écrous

Prodotto discreto arrivato nei tempi previsti. Abbastanza semplice da usare, ha però un grosso limite: gli scatti meccanici presenti durante la rotazione fanno si che fra un gradino e l'altro ci siano 4 impulsi, quindi rende obbligatorio fare un'elaborazione hw/sw apposita se si vuole avere un impulso a scatto....Mancano nel sacchetto i dadi/rondelle per fissaggio a pannello.

Cosa mi è piaciuto non lo so, ho aperto la busta e dentro ho trovato questi encoder con delle incrostazioni sul lato delle saldature, non so se è acido o altro, adesso vediamo cosa risponde il venditore!!Massimo