Altitude Posted June 17, 2013 Report Share Posted June 17, 2013 I have Illmenator's 16x4 BLM up and running and now am looking at adding it as a peripheral to my SEQV4 but I have run into a problem, the length of the leads I need for it to work is VERY short and the way I was planning on deploying it was to use a Mini DIN8 connector and cable. I can get it to work fine with a short length of ribbon cable but when I use a similar length DIN cable, the DOUT stuff works fine, but the buttons do not work reliably. I have the shield of the cable connected to ground. Would a viable solution to fix this be to buffer the serial output from the BLM? Would this work the same way as buffering a midi signal (hex inverter)? Any input would be appreciated.. Quote Link to comment Share on other sites More sharing options...
TK. Posted June 18, 2013 Report Share Posted June 18, 2013 You could use the same 74HCT541 based buffer circuit like known from the MBHP_CORE_LPC17 module: http://www.ucapps.de/mbhp/mbhp_core_lpc17.pdf Btw.: this chip would also allow you to buffer J19 for your AOUT module properly. Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Altitude Posted June 18, 2013 Author Report Share Posted June 18, 2013 (edited) perfect, already have some from the level shifter. so my premise is correct then, buffering the din should get me more length? That was the chip in the breakout box you had a pic of correct? Edited June 18, 2013 by Altitude Quote Link to comment Share on other sites More sharing options...
Altitude Posted June 19, 2013 Author Report Share Posted June 19, 2013 (edited) Can I get a quick opinion of this quick and easy board and schem? Edited June 19, 2013 by Altitude Quote Link to comment Share on other sites More sharing options...
TK. Posted June 23, 2013 Report Share Posted June 23, 2013 "BLM J9 SI" doesn't need to be buffered, remove this line. J8 and J9 RC and SC are both output pins, it seems that you handled one RC and one SC line as inputs instead - change this connection. I would propose to have a look into the MBHP_CORE_LPC17 schematic again, it's a very simple circuit! Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Altitude Posted June 24, 2013 Author Report Share Posted June 24, 2013 (edited) Thanks, that helps a lot. Have not even looked at the LPC schem (still on the STM core), Will revise Just so i have this clear in my head, SI is the input back to the core for the DIN, correct? This is my problem, the DOUT functionality works fine, the DIN stuff does not though so I figured that pin would need buffering Edited June 24, 2013 by Altitude Quote Link to comment Share on other sites More sharing options...
TK. Posted June 24, 2013 Report Share Posted June 24, 2013 SI is an uncritical signal, because it goes from a single 74HC165 output to a single input of the core, and it's already at 5V... SC and RC are the critical outputs from the core, because they go to multiple 74HC595 and 74HC165 pins Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Altitude Posted July 1, 2013 Author Report Share Posted July 1, 2013 (edited) Ok, This should be correct now: Edited July 1, 2013 by Altitude Quote Link to comment Share on other sites More sharing options...
Altitude Posted July 3, 2013 Author Report Share Posted July 3, 2013 (edited) success! I'll branch this thread with all the case and design files :smile:. Now its time so see how long I can go I suppose I should patch in J19 for a complete solution.. Edited July 3, 2013 by Altitude Quote Link to comment Share on other sites More sharing options...
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