i2c expander and LEDs

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hello all, trying control 16 led's using sfe pcf8575c.  able test chip using example  http://www.youtube.com/watch?v=uxpuzbev_ic&lcor=1&email=comment_reply_received&lc=wxsmukaibiuxghbb-mqg2gdv_r_3zm5zym77mm2pvxs&lch=email_reply&feature=email  in leds turned high/low in sequence lsb msb. wired 8575c breakout board shown in example leds very dim. can see them flickering know code , wiring works. believe issue chip
quote
pcf8575 in source mode can't provide enough current.
and wiring in
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"sink" mode (5v -> led -> pcf8575 pin)
. can provide more current leds. read somewhere perhaps pnp transistor. tried putting 330ohm resistor on each led pin (i.e 8575 i/o pins) did little help. ideas?

http://www.ti.com/lit/ds/symlink/pcf8575.pdf
from datasheet, looks part sinks current, not sources it.
i you'd want send 0 pin want turn on, resistor 5v anode, , cathode pin.


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