http://forums.leaflabs.com/topic.php?id=620 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:09:26 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=620#post-3493 Sat, 29 Jan 2011 18:21:14 +0000 gbulmer 3493@http://forums.leaflabs.com/ <p>yokurk - go anyway that feels right. BUT, time is irrecoverable.</p> <p>If you spend a month, a third of your available time, with nothing working, there will not be time available to "throw one away". The "throw one away" philosophy is about throwing something <em>working</em> away. It encourages engineers to get something that works, to act as a basis for learning and improvement. (I think this is often misunderstood) </p> <p>Spending a month learning how <em>not</em> to do something is somewhat valuable. But my experience of colleges (I used to teach undergraduate and post graduate Computer Science and Software Engineering) is you don't get the best marks for discovering and quantifying an approach which fails.</p> <p>On the other hand, if you have something that works in, say two-three weeks, then you have two and a half months to improve it. Think of this like an insurance policy; your chances of failure were significantly reduced.</p> <p>Put bluntly, if you came to me asking for a job, and you said "I really wanted to do something original, but I couldn't get anything to work until the last 20% of project time". I'd ask "how does it stack up against a cheap, well understood, off-the shelf solution?" If you don't know, I would assume you are not an engineer. I don't hire people to "be original", I hire people to be better than anyone else. That takes a lot more skill and intelligence than just trying to be original. Any fool can be original, it takes talent to be better.</p> <p>If instead you said "I wanted to do something original and better, so I built an off-the-shelf solution in a couple of weeks, tested it, found these inherent problems, fixed them, then built this much higher quality solution, which has these benefits (cheaper, fewer 'moving parts', simpler, more flexible, etc.) in the remaining 50% of the project time", then I'd be interested in hiring you. </p> <p>I have helped design recruitment and interviews, and screen and hire lots of folks. I was responsible for training hundreds of university graduates every year to be software engineers. </p> <p>One hard part of training was trying to get fresh graduates to understand that we needed better; merely different or novel doesn't matter if it is inferior. To do better they needed evidence, preferably based on reproducible measurement. Someone who happily spends months doing something 'original' without spending effort to properly understand what exists is not good to have around.</p> <p>Fresh graduates who understood this were relatively rare. Many could talk a good game, but had no evidence that they could do it. This seems like a superb opportunity to stand head and shoulders above the crowd. Somone who takes a low risk, high success path is going to stand out. </p> <p>Anyway, that's my $0.02</p> <p>PS - I should add, an (amusing to me) observation is two-three weeks will be spent on exactly the same thing if the "being original" approach doesn't work. I.e. you'll still be making a ladyada-style shield and testing it. Also, if you were going to go the extra mile, and submit a superb, evidence based, piece of work, where you compare the performance of your original solution against an off the shelf approach, you'd also build it too.</p> <p>I'd strongly recommend sketching out the "happy path", and "unhappy path" for 'submitting a superb project' use case. I think you will see things in a different light. </p> http://forums.leaflabs.com/topic.php?id=620#post-3471 Thu, 27 Jan 2011 15:19:08 +0000 okie 3471@http://forums.leaflabs.com/ <p>If you want to go barebones, it's certainly possible, but it isn't easy to get high-quality audio. But put something like this in your setup function to set the PWM to something reasonable for audio:</p> <p>// 72MHz/1024 =&gt; 70.3125 kHz PWM sampling rate<br /> // 2^10==1024 =&gt; 10-bit resolution<br /> Timer1.setPrescaleFactor(1024);</p> <p>Hook it up to an RC low-pass filter, maybe a coupling capacitor, and a speaker, and try out some sounds.</p> <p>Here's a project on guitar audio processing:</p> <p><a href="http://wiki.leaflabs.com/index.php?title=Guitar_Audio_Effects" rel="nofollow">http://wiki.leaflabs.com/index.php?title=Guitar_Audio_Effects</a></p> <p>The sound wasn't great, but it worked. I recommend an external DAC if you want higher quality audio. </p> http://forums.leaflabs.com/topic.php?id=620#post-3468 Thu, 27 Jan 2011 01:01:13 +0000 yokurk 3468@http://forums.leaflabs.com/ <p>thanks guys for your helpful comments.</p> <p>gbulmer i do agree with you that finishing the project at the earliest is our prime concern. But the thing is that i have completed the rest of the project ie. counters etc. already and still have about 3 months to work on the voice part.also i am interested in learning how this audio synthesis works .. so i prefer going without shield as far as possible. Also doing something original would help my resume maybe? However i do understand your concern about the feasibility of doing it without the shield. If i find no progress with the work in the next 1 month then i would definitely go to the shields as a final resort. i want to know if its possible to make substantial progress in creating audio from the maple directly. are there any libraries available for this? if there are no libraries i think it would be quite unrealistic to write them and go this way. At the same time porting arduino libraries for adafruit to maple may also need some work. </p> http://forums.leaflabs.com/topic.php?id=620#post-3465 Wed, 26 Jan 2011 19:46:43 +0000 x893 3465@http://forums.leaflabs.com/ <p>you're absolutly right </p> http://forums.leaflabs.com/topic.php?id=620#post-3464 Wed, 26 Jan 2011 18:28:11 +0000 gbulmer 3464@http://forums.leaflabs.com/ <p>Yes, I assume yokurk "would very much like to use other methods instead of using the ready-made shields."</p> <p>I assume the most critical part is to pass the college project, so starting with something that works, increases the chances.</p> <p>Options:<br /> 0. Buy ready made shield<br /> 1. Take WAV shield CAD, make PCB, source parts, follow LadyAda's instructions<br /> 2. Take the schematic, put it into PCB design application of ones choice, design PSB, etc.<br /> 3. Take the schematic, improve it, and design that</p> <p>All these still the problem of getting the FAT16 file system code working on Maple, and stuffing the WAV's into the audio output device quick enough, and in the right way, to get okay audio. It may well be that the real hard part is getting adequate quality audio to work.</p> <p>I deeply believe in 'plan to throw one away'. For that to be realistic, when something is important, (as opposed to just fun) my approach is get an an end-to-end solution early (first 40% of elapsed time is good). Then I can really understand the problem. Then I can make make things better based on real evidence.</p> <p>IMHO, Lots of folks start with the good intentions. They start with the objective of using an original or unusual approach. Sadly, they spend most of the project time with nothing that works, so they can't actually gather any evidence about what is important. Sometimes they get close to the deadline with nothing working, and end up making something which doesn't satisfy the requirements. At best they have no evidence, and can't prove they got any improvement on the 'dumb' or 'easy' solution. </p> http://forums.leaflabs.com/topic.php?id=620#post-3463 Wed, 26 Jan 2011 18:09:34 +0000 x893 3463@http://forums.leaflabs.com/ <p>Ops, my god - too many words for this simlest problem. why you can't use google and find tons of chip<br /> 1. recording up to 4 minutes with ability to say back<br /> 2. nothing deal with tts engine<br /> 3. why not use amy SD-DAC (may be with compress)<br /> this simple problems resolve with google at 3-5 minutes, not need maple hardly for this. maple make a big problem with maple, mini, maple and other. </p> http://forums.leaflabs.com/topic.php?id=620#post-3459 Wed, 26 Jan 2011 14:48:59 +0000 soundcyst 3459@http://forums.leaflabs.com/ <p>from yokurk's original post:</p> <blockquote><p>final option is to get an audio shield which i do not prefer. i would very much like to use other methods instead of using the ready-made shields.</p></blockquote> <p>presumably, he is referring to the adafruit wave shield? </p> http://forums.leaflabs.com/topic.php?id=620#post-3456 Tue, 25 Jan 2011 19:50:11 +0000 gbulmer 3456@http://forums.leaflabs.com/ <p>You might want to have a look at the Arduino WAV shield:<br /> <a href="http://www.adafruit.com/index.php?main_page=product_info&amp;cPath=17_21&amp;products_id=94" rel="nofollow">http://www.adafruit.com/index.php?main_page=product_info&amp;cPath=17_21&amp;products_id=94</a></p> <p>I haven't used it.<br /> I believe it has an okay quality analogue audio output, and an SD/MMC socket.<br /> An Arduino can play WAV files using it. WAV files are pretty easy to make, and for your application, there is plenty of record time on an SD card.</p> <p>You could use an Arduino, but you might want to figure out if your Maple could drive it, and try using it that way.</p> <p>Lady Ada provides enough information<br /> <a href="http://www.ladyada.net/make/waveshield/download.html" rel="nofollow">http://www.ladyada.net/make/waveshield/download.html</a><br /> you could make the shield from scratch </p> http://forums.leaflabs.com/topic.php?id=620#post-3455 Tue, 25 Jan 2011 18:53:15 +0000 soundcyst 3455@http://forums.leaflabs.com/ <p>you can read audio files from the sd over SPI, which is basically what the audio shield does.</p> <p>maple's fast enough to PWM the audio out though.. maybe not at 16 bits?</p> <p>reading wav files is easy. the header is pretty brief, and it's just sound pressure data..</p> <p>though the high density stm32 is a bit more fully featured for this application (in that it actually has a dac, and has SDIO).. </p> http://forums.leaflabs.com/topic.php?id=620#post-3452 Tue, 25 Jan 2011 08:03:13 +0000 yokurk 3452@http://forums.leaflabs.com/ <p>hi,</p> <p>i am doing my college project which is a counter system that will help reduce queues in registration desks etc. plan is to keep 3 separate counters and displays that will display the number which is given to a person who is waiting. apart from this i plan to call out the number using speakers to alert the person (in case he is not seeing the display).<br /> i have thought of 3 options for this voice. interface a mp3 player to the muc and select the playlist according to the number eg.if the number is 53 it will select the 53rd song which will call out "number 53". another idea is to use text to voice using chips which i dont think is very economical and is not exactly required for this case.third one is to use the maple to play an audio from a SD card(im not sure if this would work ,i know arduino is not very suited for this operation ,but i expect maple to do it?). final option is to get an audio shield which i do not prefer. i would very much like to use other methods instead of using the ready-made shields.</p> <p>i am new to maple and haven't yet used it to the full extent. so i think there would be other options that may be better. any help and ideas regarding this would be appreciated.</p> <p>cheers:) </p>