Sauraen Posted December 7, 2013 Report Share Posted December 7, 2013 (edited) Hi TK, Is it supported to have a single shift register provide the row selection signals for multiple matrices that have the same number of rows and the same inverted_sel mode? From another thread, it looks like this is possible, but I just wanted to make sure before having a PCB milled! For example: DOUT_MATRIX n=1 rows=8 sr_dout_sel1=1 inverted_sel=1 sr_dout_r1=2 inverted_row=0 mirrored_row=0 DOUT_MATRIX n=2 rows=8 sr_dout_sel1=1 inverted_sel=1 sr_dout_r1=3 sr_dout_r2=4 inverted_row=0 mirrored_row=0 DIN_MATRIX n=3 rows=8 sr_dout_sel1=1 inverted_sel=1 sr_din1=1 sr_din2=2 inverted_row=0 mirrored_row=0 Thanks, Sauraen Edited December 7, 2013 by Sauraen Quote Link to comment Share on other sites More sharing options...
TK. Posted December 7, 2013 Report Share Posted December 7, 2013 Yes, it works even if the DOUT_MATRIX and DIN_MATRIX control different number of rows - they are always in sync and don't disturb each other. At least software-wise. Hardware-wise you have to expect less brightness on the LEDs if no dedicated sink drivers are used. Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Sauraen Posted December 7, 2013 Author Report Share Posted December 7, 2013 Thanks! I am using dedicated sink drivers, a Darlington array (Mouser 757-TD62083APGON), hence the inverted_sel=1. :) Thanks for having the DOUT boards support these too! Quote Link to comment Share on other sites More sharing options...
novski Posted December 8, 2013 Report Share Posted December 8, 2013 Hi Sauraen I compared the two spec Sheets of ULN2803 and TD62083APGON. I use the ULN2803... Thats very interesting because i coldn't find a difference beside price. Can you tell me why you selected it? - im just curious... At least in the Swiss Mouser Store the ULN2803A is cheaper... (i assume the prices can vary between countries.) http://ch.mouser.com/ProductDetail/STMicroelectronics/ULN2803A/?qs=sGAEpiMZZMvAvBNgSS9LqpP7ived4CP2 best regards novski Quote Link to comment Share on other sites More sharing options...
Sauraen Posted December 8, 2013 Author Report Share Posted December 8, 2013 I'm pretty sure I just went to transistor arrays, filtered by quantity = 8, ordered them by price, and picked the cheapest one that was in stock. According to my BOM spreadsheet it was $0.81 (~0.59 euro). But I don't think it matters which kind of sink drivers very much, I used a bunch of discrete MOSFETs in TO220 packages bolted to a heatsink in my ASIDITY project, and it works fine--but that was because there were around 750 LEDs in the matrix! Quote Link to comment Share on other sites More sharing options...
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