v2.1 Opto endstops salvage....is it possible?

Hi to all on the forum,

Is it possible to replace just the optical sensor on an opto PCB? i have just had one blow/fry and it looks as if the infrared emitter is dead. Checks with a multimeter return a '1' compared to '0' for pins on a functioning board. Resoldering joints does nothing to solve this either. I do not think its anything to do with the opto cable either as connecting this to another opto works fine.

As the remaining components are working on the board, is it possible to replace just the optical sensor?

I have tried to find something on ebay but there are a number of different options available, All of which have only 4 pins instead of the 'standard' 5.

Would any 4 pin sensors work as a drop in replacement or is it a '5 pin or nothing' deal?

I need to look into the different optos as they have a number of different values for things I'm not familiar with (Current Transfer Ratio, Fall Time, Forward Current, Forward Voltage, Rise Time, Collector Emitter Break Down Voltage, Collector Output Current)

Time to learn some terminology...

Thanks

Raj

Can you find this optical sensor somewhere? It's deprecated for several years now.

No, 4 pin ones aren't a drop in replacement. You'd need a new one, for example this one ( $4 ): [reprap.org]

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hi Traumflug,

I have found a seller of the deprecated opto, the price is more than theopto you've mentioned. I believe on the wiki page it mentions that with the correct wiring, this can be used with gen 3 electronics but it does not mention what amendments need to be made.

I'm having a look to find this out.

Thanks

Raj.

To connect an Gen7 Opto Endstop to a Gen3 electronics you need to get the wiring right, that's all. For example, modern opto endstops have GND on the center pin, the original Gen3 ones have it on one of the outer pins. Comparing the layouts of the Gen3 board with that of the opto endstop and using a voltage meter should help.

A similar procedure is described here: [reprap.org]

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hello again Traumflug,

Thanks for confirming that. I got as far as the wiring gnd,sig,vcc wires correctly it wanted to be extra sure there were no pull up resistor shenanigans involved as with mechanical endstops. As I said, I don't want to fry anything else.

Thank you very much for your help.

Raj.

Hi to all,

With regards to wiring up the gen6/7 style opto to a gen 3 stepper driver, there are some changes which are needed. See below.

The pins on the v2.1 endstop are VCC, Sig, GND.

For the Gen6/7 endstop[ the pins are Sig, GND, VDD.

Therefore you cannot plug in the replacement and go. In order to run the Gen6/7 opto, you will need to change the wires around on the current connector you are using or make a different connector. Whichever is easiest for you.

I have attached pictures from the wiki for reference.

Thanks

Raj