Hi all,
I'm using one of these bi-directional logic level converters to interface a Teensy 3.5 with the MOSFETs on a RAMPS (originally D8, D9 and D10 on the mega2560): https://www.sparkfun.com/products/12009
Everything works really well once my sketch gets going / the pins are configured, however, when I first power-up or reset the Teensy all 3 MOSFETs turn on briefly until the sketch starts. This is obviously not at all desirable, so I've tried using 10K pull-down resistors on the low voltage side logic pins leading from the Teensy, but it made no difference.
I was considering trying pull-down resistors on the high-voltage side logic pins leading to the MOSFETs, but I thought that might make the "bi-directional" properties of this converter board stop working... So I figured I'd ask here for opinions.
The RAMPS board is being powered with +3.3v for +3.3v and +5v and everything else works as expected (when I get closer to finishing, I'll be running an LCD of its own +5v supply) with the steppers moving smoothly and fast so I'm pretty happy with the way it's working except for this one issue.
Any help appreciated,
Jason.
I'm using one of these bi-directional logic level converters to interface a Teensy 3.5 with the MOSFETs on a RAMPS (originally D8, D9 and D10 on the mega2560): https://www.sparkfun.com/products/12009
Everything works really well once my sketch gets going / the pins are configured, however, when I first power-up or reset the Teensy all 3 MOSFETs turn on briefly until the sketch starts. This is obviously not at all desirable, so I've tried using 10K pull-down resistors on the low voltage side logic pins leading from the Teensy, but it made no difference.
I was considering trying pull-down resistors on the high-voltage side logic pins leading to the MOSFETs, but I thought that might make the "bi-directional" properties of this converter board stop working... So I figured I'd ask here for opinions.
The RAMPS board is being powered with +3.3v for +3.3v and +5v and everything else works as expected (when I get closer to finishing, I'll be running an LCD of its own +5v supply) with the steppers moving smoothly and fast so I'm pretty happy with the way it's working except for this one issue.
Any help appreciated,
Jason.
