Here is a video I took of the output signals from my RAMBo, hopefully helping with troubleshooting.
I still can’t seem to get the laser to turn off EXCEPT when I reversed the polarity of the TTL connection. However, doing that I can’t get the laser to turn on.
I seem to get the best signal using M42 P45 Sxxx
Using M3 Sxxx or M106 gives me a really dirty signal on the oscillascope for some reason.
Important details:
-12v laser with 5v TTL control (from China)
-Latest Marlin firmware from V1 (dual endstop)
-Channel 2 in the video is measuring between (-) on the MX2 rail and (-) on the power supply (ground)
Sorry, yep. I’m measuring 2 signals in the video.
-The yellow signal is measuring TTL (+) to TTL (-)
-The green signal is measuring TTL (-) to power supply (-)
I just wanted to make sure on the green signal that TTL (-) was actually connected to the power supply (+) which it appears to be.
Any clues as to why the laser wouldn’t turn off completely at S0? It’s definitely a lower power level but it still burns through cardboard.
If you have a resistor in the 1kOhm-10kOhm, you can connect it between the ttl(+) and gnd. It may be enough to “pull down” the voltage to ground when it is supposed to be off.
I am not sure why that is around 1V. If you disconnect the laser, and use your silly scope, does pin 45 stay around 1V still?