I was surfing on Tindie tonight, and came across this which I think is what you were asking for:
https://www.tindie.com/products/land_boards/rpio-tiny-2/ On Dec 31, 2015 11:01 AM, "Andy Tefft" <[email protected]> wrote: > Thanks for the quick feedback, guys. > > I'll probably breadboard up a transistor for now, and a little converter > like that can permanently go inline in my connecting cable even though I > only need a single channel. It would be cool if someone made a breakout > board for the pi that had an optional level converter on every (or even > several) gpio output, that would be really useful for prototyping. > > > On Wed, Dec 30, 2015 at 5:29 PM, David Forbes <[email protected]> > wrote: > >> Andy, >> >> You can use an NPN transistor (2N3904 or 2N222A or whatever) and a couple >> resistors to boost the Pi signal to 5V. Pi output through a 10K resistor to >> Base, Emitter to Gnd, counter fed from Collector, Collector also tied to 5V >> through a 1K resistor. Should work up to about 1 MHz. >> >> >> On 12/30/15 2:54 PM, Andy Tefft wrote: >> >>> >>> Initial quick tests are good with one exception - I had just connected an >>> AVR output to one of the pins on the reset button on the counter and the >>> AVR was able to toggle that output and reset the counter (pretty sure I >>> was >>> powering the AVR with 5V). This same trick does not work with the pi, >>> presumably due to its puny little 3.3v-level outputs. Anyone have a >>> standard, simple go-to for interfacing between old TTL circuitry and a pi >>> or something like it? >>> >>> >> >> -- >> David Forbes, Tucson AZ >> >> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send an email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/56845AE1.5070000%40dakotacom.net >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/CAM1F4kQzz%3DgMV0qcO26Je3DwkMbbGjxtC%2BD7Kwfpr04eX7tPsA%40mail.gmail.com > <https://groups.google.com/d/msgid/neonixie-l/CAM1F4kQzz%3DgMV0qcO26Je3DwkMbbGjxtC%2BD7Kwfpr04eX7tPsA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAJrqPH8Nss3eoYPBk3Yv6Mf%2BKAFvjfSSmFg8iyg5hem38upX%2BA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
