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Topic: Using TPIC6B595N or MAX7219 (Read 1 time) previous topic - next topic


From the schematic, your pin declarations are wrong.  

You have pins 5, 6 and 8 on the schematic and 7, 9, 10 and 11 in the sketch.

Just change your jumpers to match the code.


Yes, that's an error between computer design and real life :) but it is ok, the pins are as they are in the code... very good observation but that's not the issue..


Nov 30, 2012, 07:32 am Last Edit: Nov 30, 2012, 07:37 am by Stijn Reason: 1

The TPIC6B595 can only pull pins low. Current limit resistors to +5V drive the anodes high, the '595 outputs bring  the cathodes low to turn them on.


Sorry but I'm pretty new to electronics so this might be stupid... does this mean that I have to connect the positive side of my led to my 5v and my negative to my resistor and to the TPIC6B595N? I made a new sketch like this.

In any case, I'm basing my design on this link. My original question was if it would be better and possible to use 2 times the TPIC6B595N to build a matrix, if I understood correctly this is not possible?



Yes -
+5 - resistor - anode, cathode to TPIC6B595

Sure, can use two TPIC6B595.

One will control current into the anodes, one will sink current from the cathodes.
Connect the anode control between the resistor and the anode.

Connect 2nd TPIC6B595 between resistor & anode.

So, drive the anodes, letting them go hi/low as needed for a column with 8 outputs of one shift register.
WIth the other, pull the cathode low for that 1 column.

Anode current is then either going into the anodes, or into the anode shift register.
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