Beat Posted October 2, 2012 Report Share Posted October 2, 2012 What do you expect, are the limits of one LPC17. How many LCD's can be driven by one LPC17? I want to use I2C-Displays if possible, price is not so important. Can I drive 128 Encoders with one LPC17. Where could be a problem? Is it possible to drive 128 LED-Rings also with the same LPC17? thanks Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted October 2, 2012 Report Share Posted October 2, 2012 What do you expect, are the limits of one LPC17. How many LCD's can be driven by one LPC17? I want to use I2C-Displays if possible, price is not so important. Can I drive 128 Encoders with one LPC17. Where could be a problem? Is it possible to drive 128 LED-Rings also with the same LPC17? thanks Which firmware will you be running? The only one for an LPC17-based controller is MidiIO128...the features, or, "limitations" are called out in it's wiki page. That would be a good place to start. Quote Link to comment Share on other sites More sharing options...
Beat Posted October 2, 2012 Author Report Share Posted October 2, 2012 Yes this wiki page I know. I want to start with this firmware and I know that there will be in maximum 64 Encoders per Core. But I think (and I read it in this forum somewhere) that the limit of this core is not yet reached with scanning of 64 Encoders. And in the wiki is written to connect 1 2x20 LCD. But I read in the forum somewhere, that someone has connected 5 LCD's. For my application, in the end I have to write a lot of code myself I know. But to collect some of the knowhow people already made, I started this thread. Quote Link to comment Share on other sites More sharing options...
smokestacksproductions Posted October 2, 2012 Report Share Posted October 2, 2012 Yes this wiki page I know. I want to start with this firmware and I know that there will be in maximum 64 Encoders per Core. But I think (and I read it in this forum somewhere) that the limit of this core is not yet reached with scanning of 64 Encoders. And in the wiki is written to connect 1 2x20 LCD. But I read in the forum somewhere, that someone has connected 5 LCD's. For my application, in the end I have to write a lot of code myself I know. But to collect some of the knowhow people already made, I started this thread. I think 64 encoders is a limitation that is proportional to the number of shift registers allowed. You can hook at least 8 lcd's though Quote Link to comment Share on other sites More sharing options...
Duggle Posted October 2, 2012 Report Share Posted October 2, 2012 (edited) It is definitely possible to connect a much larger number of shift registers than just 16 chips. The problem is not the speed of the microcontroller: in the blog article I have 30 chips connected (using as STM core 60% as fast as LPC17). This is by no means an upper limit either. The 16 chip limit is advised due to typical poor signal integrity of typical midibox wiring! e.g.putting a 100R resistor in series with the source driver can improve situation dramatically. keep the SCLK, SDATA, SRST the same length close to each other. (The SCLK is the important one, in terms of integrity problems)make the ground plane or ground return path run close to these signals to minimize the area of the created loop.use a source termination resistor of say 100R If you have a CRO you will be able to verify the affect of each of these measures, if not, just do it that way anyway. Edited October 2, 2012 by Duggle Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.