View Full Version : Paul - Audio question

02-01-2013, 12:33 PM
You mentioned possible audio for the Teensy3 (http://forum.pjrc.com/threads/15876-Thinking-of-getting-Teensy3-for-my-project)

Do you have any idea what the dimensions will be? Size of the Teensy? Bigger/Smaller? Will there be something in 3 - 6 months? Anything I can buy now since the post can take a month? :) Willing to be beta tester

Hopefully it can be I2C, because of the LCD using SPI and I have read it takes a bit of work to get multiple SPI devices working on the same bus

02-01-2013, 04:58 PM
Check out this thread:


02-02-2013, 12:02 PM
I think I found the board the guys talk about

Do you recommend I get that board?

02-02-2013, 12:21 PM
It's cheap and small! Some things I've noticed:
- The input jack is wired to the microphone input. The line inputs are not connected (they're not even broken out to pads on the board). So if you need line-input, this is not very convenient.
- The output jack is wired to the headphone output. The line outputs are not connected (ditto). Headphone out is useful since it has an on-board programmable volume control. But again, if you want to follow this with your own line-out at fixed gain, that won't be very easy.
- For me, the headphones are very quiet.

But it's $20.
For double that, you could try the Open Music Labs codec shield, which uses the same codec: https://www.sparkfun.com/products/11290
I'm interested to hear any suggestions of other codec breakout boards below ~$50!

02-02-2013, 12:46 PM
I think I will order one end of the month. I just need to play gun shooting sounds for laser tag. I will use 8 ohm speakers I can't afford the space that a shield needs. The proto board seems to be about the size of the 1.8'' adafrut LCD

02-27-2013, 02:06 PM
seconded .. any news on a/the audio codec shield? all the existing ones seem to be a tad too bulky a/o not overly flexible, as hpyle mentioned - would be nice in fact getting rid of pcb mount jacks altogether, or keeping them optional, which would make it slightly easier to condition inputs and outputs as one pleases (not all audio works on mic or line levels, after all. also of advantage when it comes to putting things into a nice box or behind a panel)

02-28-2013, 05:58 AM
Another kickstarter for Paul?

I will order 10 so long if they can be the size of the teensy :)

02-28-2013, 10:17 AM
One of the biggest challenges is choosing which type of connectors to use, for such a small form factor.

Obviously there should be at least 1 3.5mm "headphone" style jack. What about amplified output? Mic or line level Input?

02-28-2013, 11:13 AM
Maybe use the same principles that Arduino use and create components

Component 1
Has form factor of the Teensy 3. It should have pin outs like the Teensy so that it is possible to solder any type of jack onto it if you want a jack or just solder wires to it. It should be possible to access the headphone and the normal line out. It should have the same kind of PCB design as the Teensy so that someone can solder headers onto it if they want. It needs to have volume control that can be configured programmatically

Component 2
Plugs into the component 1 and it has gives amplification, but maybe it can rather be part of the main component (component 1). For me, I need something that is tiny that can run this speaker http://www.altronics.com.au/index.asp?area=item&id=C0604B that I can use in my laser tag guns

Component 3
Can plug into component 1 or component 3 and it gives you a headphone jack

I can give you an indication of the size of my "brain" that I am going to build
This battery might still be a bit too long, but this is what I am basing my design on
So my "brain" box will be the length of the battery and I need to be able to fit everything in that length
- LCD screen
- NFC reader
- Teensy
- Sound card
- Radioblock

I can maybe get away with a card the size of the Adafruit LCD http://www.adafruit.com/products/358 as long as it is as flat as possible

Others probably have the same limitations and that is why the Teensy is so great to use

02-28-2013, 01:42 PM
For just playing sounds for a gun, you might want to look at the ISD1820 chips. These provide 8-20 seconds of a single sound. and are often used in the musical greeting cards. You can either get the raw chip, which you would wire into a proto board or pcb, or you can get one with pins, etc. that you could hook to your teensy. I bought the following, but I haven't done more than test it playing a simple sound using a simple unpowered speaker I got at Radio Shack: http://www.ebay.com/itm/ISD1820-Voice-Board-Voice-Module-Sound-Recording-Module-/221180636859?pt=LH_DefaultDomain_0&hash=item337f64aebb

If you want to play multiple sounds, you can get WTV020-SD-16P chips that have a micro SD card to hold the sounds. This chip is the basis of many of the Arduino sound shields. A common complaint is these units are real picky about the size and quality of the micro SD cards. http://www.ebay.com/itm/WTV020-SD-16P-U-Disk-Audio-Player-SD-Card-Voice-Module-MP3-Voice-Module-/221152563949?pt=LH_DefaultDomain_0&hash=item337db852ed

Over on the Arduino forum, I first found about the WTV020-SD-16P from this post which includes a basic library. The original author used it to create a light saber with sounds. I haven't looked into details yet, but I suspect the programming is either i2c or spi. I don't think it used asm, so you might be able to use it on the teensy 3.0 unchanged. http://arduino.cc/forum/index.php/topic,117009.0.html

For basic sounds without speaker, you could use a passive beeper or buzzer, assuming Paul has ported the Tone library to the Teensy (beeper makes a single click and turning it on/off rapidly can produce a tone, while buzzer emits a continuous sound once triggered until it is canceled). The ones I bought are 5v that I used with the Arduino, and I don't think I've tried it on the Teeny yet, but you should be able to find 3.3v versions. http://yourduino.com/sunshop2/index.php?l=product_detail&p=211

On my steampunk camera setup (see my icon picture), I have a telegraph key to fire that camera, and I added telegraph sounds using the beeper on the Arduino. Like you, I like the form factor of the Teensy, and I have been planning to move it to the Teensy. I want to upgrade to using recordings of more complex sounds, but so far, I haven't been focused enough to get to the sound portion yet.

I have found 2.5mm and 3.5mm stereo connectors for mounting on panels at my local electronics store (even Radio Shack has them if you search through the cabinets at the back), but these aren't as convenient to mount on proto boards. I made a little wood frame to hold it, but after a search I found a Shogyo component that I just ordered that provides a 2.5mm connector for PCB mount (SJ-0252-3RT)t: http://www.shogyo.com/pdf/sj-0252-3rt.pdf

If you wanted the more standard 3.5mm connector, you can get breakouts like: http://www.ebay.com/itm/300655692210?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

If you want the ability to remove/connect devices, besides the 2.5mm/3.5mm phono connector, you can get RJ-11 (US phone cable) for 6 wires or RJ-45 (ethernet) for 8 wires connectors. In addition, I've gotten a bunch of wafer headers from dipmicro, that are a little tedious to make, but it allows me to make a wire connection of a particular size: http://www.dipmicro.com/store/SET-HDR


02-28-2013, 11:14 PM
hi ... good to see this still seems alive.

definitely a small / teensy-esque form factor sounds nice. as to i/o, amplification and buffering, my 2 cents would be, the more flexible the better. after all, people planning to bother with that kind of thing are likely to have special needs... some might want AC, others DC coupled i/o. others line, mic or other ranges (10 V pp is common with a lot of audio gear, for example, but that might already prove a bit tricky if the op amps were powered from the Vin). don't know whether that's feasible to cater for all those wishes, but it probably would mostly be a matter of having people solder on resistors around the op amps themselves, with values as required.

03-01-2013, 11:28 AM
Thank you. I ordered a couple and will see how it goes