The LCDuino-1 I/O processor
Oct 11, 2009 at 2:51 AM Post #121 of 403
I like playing around with the code for these kind of things, but this would be too much of a distraction during school ...I'll have to wait till winter break =)

It would be nice to have an on board regulator so that power could be easily tapped from an amp's power supply.
 
Oct 11, 2009 at 3:07 AM Post #122 of 403
Quote:

Originally Posted by rds /img/forum/go_quote.gif
It would be nice to have an on board regulator so that power could be easily tapped from an amp's power supply.


that's one application for the proto holes. we made sure they were big enough to fit 7805 style flat leads thru.

example:

3969440999_87f9c24163.jpg


that was 9vdc in and after the 7805, it went right to the +5v line on the board.

not everyone needs it but if you do, the proto holes are your friend
wink.gif


on that photo, the orange electrolytic is over analog-0 input. that LCDuino board was controlling my espresso machine and the sensor comes via an LM35 temperature chip. that line gets smoothed by the cap and so I don't have to worry about multi-reading the value to smooth it out, the cap does that for me. there was *just* enough room to fit the cap in between the analog pin and a nearby ground pad
wink.gif
 
Oct 11, 2009 at 7:53 AM Post #124 of 403
some more software progress: some early success with a universal learning receive mode, for IR. there's even a 'gui' where you can go thru the functional keys, one by one, and assign YOUR own ir codes to them. the results are saved in eeprom and used at each power-up.

to get into this mode, you press a special soft-reset button at power-on time or any time the welcome logo appears. then it cycles you thru the various buttons (keypad keys, arrow keys, etc) and asks you to press the key that is displayed on the lcd. you press them, it asks the next until they are all assigned. that's it; then it takes you out of setup and into 'use' mode. you can re-do setup at any time (power-up and hold the soft-reset button or invoke the welcome banner and hit soft-reset button).

until now, you had to edit the source code to define keys. now, there's a GUI in the LCDuino code, itself.
 
Oct 11, 2009 at 8:00 AM Post #125 of 403
This has really got my interest. I am envisaging an input selector, vol control, and bias meter for my new tube amp i am working on. Good work chaps.
 
Oct 11, 2009 at 8:16 AM Post #126 of 403
Hmm a bias meter... Very interesting, but can it be reasonably accurate down to small adjustments? Maybe using a motorized trimpot rotator? hehe. Or are we simply talking about simple DC measurement? I wouldn't want the meter constantly measuring the bias however.
 
Oct 11, 2009 at 9:21 AM Post #127 of 403
I was thinking just to monitor, not active bias.

What sort of resolution do we have? I use 10ohm 'test' resistors in the cathodes of my el34 amp, so only need accuracy down to 1E^-2 or so.

Just thinking out looud really. I will probably buy one and have a play.
 
Oct 11, 2009 at 2:54 PM Post #128 of 403
the internal a/d's have 10bit (1024) resolution, from 0-5v.

you'd want to front-end the ard cpu with a buffer of SOME kind, I would think.

what would be really cool is to get hold of some DMM chips that read voltage (well) and output an i2c stream or even serial. I have some old DMMs that have rs232 serial out on any of their measure ranges.
 
Oct 12, 2009 at 3:55 AM Post #129 of 403
This looks like an awesome project and coincides nicely with my desire to create a similar device. I got an Arduino board a few weeks ago and have been playing with it, getting familiar with the environment. I like it a lot.

What I'd like to do is make a preamplifier, controlled with the Arduino via buttons and eventually a remote. I'll be starting some prototyping this afternoon and have some shift registers (595 for output, 4021 for input) and 3-wire LCD using the LCD3Wire library and 4094 shift register.

My goal is to have:
- 4 inputs - 1 analog, 3 digital - as inputs to the preamp, the digital inputs going through a DAC (external at the moment, through my LD DAC_1, but eventually through an internal or external Opus DAC). Digital inputs would be USB (with USB > SPDIF), coax, optical (with TOS > SPDIF), input selector would switch between the SPDIF inputs and send that through to the DAC which sends back the analog signal via a 'loop input'.
- PGA volume control with a rotary encoder, with the Arduino saving volume level / mute state in eeprom.
- Multiple outputs (2 or 3) with the option to bypass the PGA and have line level output on each output.
- e24 (or similar) power control that has mains output to plug amps into so that I can power off the preamp (by button or remote) and power is cut to the amps as well.

Is any of the code you have been working on available? It would really help me and I could contribute what improvements I can as well.
I could also help with prototyping if you need extra boards built and tested.
 
Oct 12, 2009 at 8:53 AM Post #130 of 403
elliot42, the current firmware is still being massaged for the prototype team, we will make the source available. The prototype team is already full, we have no more boards at this time. Please wait for the production version,
 
Oct 12, 2009 at 5:00 PM Post #131 of 403
Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif
some more software progress: some early success with a universal learning receive mode, for IR. there's even a 'gui' where you can go thru the functional keys, one by one, and assign YOUR own ir codes to them. the results are saved in eeprom and used at each power-up.

to get into this mode, you press a special soft-reset button at power-on time or any time the welcome logo appears. then it cycles you thru the various buttons (keypad keys, arrow keys, etc) and asks you to press the key that is displayed on the lcd. you press them, it asks the next until they are all assigned. that's it; then it takes you out of setup and into 'use' mode. you can re-do setup at any time (power-up and hold the soft-reset button or invoke the welcome banner and hit soft-reset button).

until now, you had to edit the source code to define keys. now, there's a GUI in the LCDuino code, itself.



That's pretty impressive. I thinks this is a first for Arduino S/W. How much memory does this code take?
 
Oct 13, 2009 at 4:13 AM Post #132 of 403
Oct 13, 2009 at 4:21 AM Post #133 of 403
if that IR transmitter is like most of the others, I think it would work.

there's no RF receive on the arduino, but that remote you listed seem to have either a local or remote ir blaster.

NEC and sony style protocols (a lot use NEC) are working well. philips rc5/rc6 still needs more work but should run eventually (they're tricker than the other types since they don't send the same keycode on every press of the same key. that complicates things).
 
Oct 13, 2009 at 7:12 AM Post #134 of 403
You know, with the code you're writing it sounds like it wouldn't be all that hard to make a the LCDuino into a universal remote with a screen like the fancy logitech ones.
 
Oct 15, 2009 at 11:03 AM Post #135 of 403
First things first, I want to thank Ti and LinuxWorks sincerely for taking on this project, it makes this hobby soooo much more interesting than it already is!

Secondly I wanted to ask if it could be done, and if how, to install a LCDuino into a chassis with a Sigma22 and messure like 4 rails of voltages and output them on a 16x2 or a 20x4 LCD.

Greetz Ava and the most of luck with the LCDuino!
 

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