Reprap Compatible Opto End Stops

RepRap compatible Opto End-stop using an Opto End stop with a 0.5mm beam slightly smaller than the HB102 beam width of 0.8mm.
The opening of the interrupter is 5mm allowing for a 3mm black perspex interrupter tag designed for use on Huxley Seedling but can be used on All RepRaps.
The output of all three versions is an Open collector active High signal.
Active high means a 1 is made when the end-stop is triggered.
The goal of this project was to design
- A small low cost PCB < £1.00 for 3 bare PCBS.
- Low cost of components.
- With a smaller beam to break.
- Wider opening for a 3mm interrupter and little more clearance.
- Three circuit build configurations. ECO, standard, and Illuminated.
- Reprap Standard mounting centres. (holes)
- PCB size is 25.5mm x 10mm metric or 1.004″ x 0.394″ in Imperial
All hardware & software development work is carried out under the GNU General Public License. Any products developed from these projects are covered by Creative Commons Licensing – Attribution – Non-Commercial. All drawings of product designs are covered by UK Copyright Law unless stated otherwise.
Master CCT of the PCB

- ECO
- Standard
- Illuminated.
More information can be found in the following sections or to find out more about making the three schematics yourself can be found on my Wiki
ECO Schematic

(easy to build Discreet components)
The Led is on all the time for setting up your end-stops.
Once the RepRap is set-up the link can be removed as you do not need to see the led going off/on.
In the same way your scanner or paper printer has not got a Led on its end stops.
An open collector drive gives better noise immunity.
(however adding a 10K surface mount pull up resistor is an option.)
Standard Schematic

(more difficult to build Discreet components with one Surface mount resistor)
The Led is off all the time and is only activated when the end stop is triggered.
This gives the same function as most of the other RepRap end stops.
Illuminated Schematic

(difficult to build Discreet components with two Surface mount resistors)
The Led lights only when the end stop is triggered.
Its function can also be enabled and disabled by the link.
An open collector drive gives better noise immunity.