Build: Lowrider 2
Controller: Ryan custom Rambo 1.4a
Laser: NEJE “30W” laser
Firmware: Latest Marlin DualLR
Power Supply: Meanwell 12VDC 29A
After reading multiple posts, the latest in April, it appears that one can choose not to use the included power adapter board and wire ground and 12VDC directly to the laser and wire TTL from pin 45 on the Rambo directly to the laser. Could someone please confirm that? I am using the same power supply for the Rambo, the laser and a Raspberry Pi. There was some talk about floating voltages and ground and separate power supplies, but I did not understand. Is using the same Vcc and GND okay?
On temperature wiring, I have read dozens of posts. The NEJE LED board apparently provides 200 baud communication. I’ve read several posts about using that, but I don’t have that board and am hesitant to add more to my Lowrider 2. I’ve already made it complex enough. Without any board, it looks like the NEJE laser’s pin 4 is a 10K thermistor. I found a diagram for reading the value. My first thought was to add an MCP3001 A/D converter wired to the Raspberry Pi’s SPI pins. Things were getting way too complicated, so I junked that idea. What about using the temperature inputs on the Rambo for a 3D printer’s hot end or bed? Is that possible? Would there need to be some addition circuitry? A pot to bring it to the normally used 100K thermistor? Not being a EE, I am guessing. The thermistor curve would be different. Does the Marlin firmware have a built in Steinhart-Hart equation to which you could provide the 3 values for estimation/interpolation? Which wires would need to be connected to which Rambo pins? Would the Marlin’s gcode allow you to read the temperature? Same as a 3D printer? Thank you!
