noobish question. can i add a pull-up resistor to resistor voltage divider?
Yes, but you shall alter the voltage. How much by depends on the comparative ratios of the pull up and the voltage divider itself.
For that reason, I would not recommend it. If you need a supply rail then use a regulator.
i have already a supply voltage(made it from +5v and few diodes connected in series). i need pull-ups for talking lines. the problem is that i cannot initialize my sd card and i checked almost everything, power suply seems ok, speed is 125kHz during initialisation, i give quite a bit of time for voltage stabilisation and CMD0, so now it's only pull-ups and mistakes in the code left.
i was thinking about diodes, but simple ones probably support only very low frequency. i mean if i use diodes, i can use pull-ups with them.
so is there a way besides buying a chip for level shifting?
i guess it's not worth the effort, i'll just buy a chip.
Somewhere I read that some newer SD cards rely on edge transition and therefore don't work well with a resistive level shifter.
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