MichaelMeissner
Senior Member+
I tend to like using Teensys to drive small number of WS2812B's for costumes. In the past, the LC was my favorite Teensy for this purpose due to the built-in level shifter for the A3/17 pin.
But recently I moved to using the Teensy 4. Both of my previous LC's had solder damage due to heavy usage, and I like the idea of the on/off pin to turn off the Teensy. Originally I was going to VIN, A3/17, and ground connected to a SN74LV1T125 to safely convert the voltage. But I discovered that turning off the Teensy's VIN pin is still active when the microprocessor goes to sleep (which makes sense when I think about it), which meant that the WS2812B's would be left on, unless I specifically turned them off before pressing the on/off button.
Now it turns out, the WS2812B's that I was using can run at 3.3v, so I just used the 3.3v power (which is cut off when the power shutdown occurs). But not all of my WS2812B's can run at 3.3v. So I was wondering if there was a chip similar to the SN74LV1T125, but instead of OE being set to ground to enable the conversion, I would want OE being set high. Then I could connect:
What I'm looking for is something in the same form factor (SSOP) as the SN74LV1T125 but OE is inverted. Sure, I could use an inverter chip along with the converter, or more likely just keep using 3.3v, and making sure each LED functions at 3.3v.
But recently I moved to using the Teensy 4. Both of my previous LC's had solder damage due to heavy usage, and I like the idea of the on/off pin to turn off the Teensy. Originally I was going to VIN, A3/17, and ground connected to a SN74LV1T125 to safely convert the voltage. But I discovered that turning off the Teensy's VIN pin is still active when the microprocessor goes to sleep (which makes sense when I think about it), which meant that the WS2812B's would be left on, unless I specifically turned them off before pressing the on/off button.
Now it turns out, the WS2812B's that I was using can run at 3.3v, so I just used the 3.3v power (which is cut off when the power shutdown occurs). But not all of my WS2812B's can run at 3.3v. So I was wondering if there was a chip similar to the SN74LV1T125, but instead of OE being set to ground to enable the conversion, I would want OE being set high. Then I could connect:
- Teensy VIN -> SN74LV<xxx> VCC + LED VCC
- Teensy 3.3v -> SN74LV<xxx> OE
- Teensy Ground -> SNL74LV<xxx> Ground + LED ground
- Teensy A3 pin -> SNL74LV<xxx> A
- Led DIN pin -> SNL74LV<xxx> T
What I'm looking for is something in the same form factor (SSOP) as the SN74LV1T125 but OE is inverted. Sure, I could use an inverter chip along with the converter, or more likely just keep using 3.3v, and making sure each LED functions at 3.3v.
