Cooper Bills and Anish Borkar, two EE students at Cornell, have created The Handy Lab Buddy, a multifunction device, based around an ATMega 644, that measures voltages, logic levels and frequencies, and then “speaks” the results via a wavetable. They write:
The Handy Lab Buddy is a tool every ECE should have. The four features of this tool include a talking voltmeter, logic probe, voltage averager, and frequency measurer. As a cheap and accurate device that outputs whatever being measured through speakers, it’s one of its kind and an essential tool for lab work.
The “voltage averager” feature is particularly interesting. It takes multiple voltage samples, and then outputs the average, as well as the min and max levels, over the speaker.
If you want to do this project yourself, they provide the schematic and code on the website. Alternatively, you could try something similar with an Arduino and a WaveShield.
WaveRP is an Arduino library for recording and playing Wave files with the Adafruit Wave Shield. It records 8-bit mono files at 4,000 to 44,100 samples per second. Use of the Wave record/play library, WaveRP, requires the following: Arduino with a 5 volt 328 processor. Low noise power source such as a nine volt DC adapter or battery. Adafruit Wave Shield (version 1.1 is best but 1.0 works) Microphone preamp. A circuit for a simple preamp is included in the documentation. Microphone, PC type with 3.5 mm plug. See the documentation for details. SD/SDHC formatted with 32KB allocation units.
The Wave Shield!
Adding quality audio to an electronic project is surprisingly difficult. Here is a shield for Arduinos that solves this problem. It can play up to 22KHz, 12bit uncompressed audio files of any length. It’s low cost, available as an easy-to-make kit. It has an onboard DAC, filter and op-amp for high quality output. Audio files are read off of an SD/MMC card, which are available at nearly any store. Volume can be controlled with the onboard thumbwheel potentiometer.
This shield is a kit, and comes with all parts you need to build it. Arduino, SD card, tools, speaker and headphones are not included. It is fairly easy to construct andanyone with a successful soldering project under their belt should be able to build it.
The shield comes with an Arduino library for easy use; simply drag uncompressed wave files onto the SD card and plug it in. Then use the library to play audio when buttons are pressed, or when a sensor goes off, or when serial data is received, etc. Audio is played asynchronously as an interrupt, so the Arduino can perform tasks while the audio is playing.
Can play any uncompressed 22KHz, 16bit, mono Wave (.wav) files of any size. While it isnt CD quality, it is certainly good enough to play music, have spoken word, or audio effects. Check out the demo video/audio at the webpage
Output is mono, into L and R channels, standard 3.5mm headphone jack and a connection for a speaker that is switched on when the headphones are unplugged
Files are read off of a FAT16-formatted SD/MMC card
Included library and examples makes playing audio easy
Please note that the library rather bulky, requiring 10K of flash and more than 1/2 K of RAM for buffering audio. It works fine using an ATmega168-based Arduino (or compatible) but for more complex projects I strongly recommend upgrading to an ATmega328!
More information, including design notes, schematics, library, examples, etc is at the Wave Shield webpage
Latest Wave shield kit, works with more SD cards and with older NG Arduinos! Unassembled
2 GB SD card (brand may change, but we test one of each kind to verify it works well)
Speaker – 3″ diameter (77mm), 8 ohm impedence, good response between 200Hz to 10KHz (10KHz is the max frequency the Wave shield can make). The speaker is rated for 1W so if you want you can even stick a small amp between the shield and the speaker to boost up the volume
Big news! The Arduino starter pack kits from Adafruit have new wires included! These wires are an improvement from the previously included 2 feet of solid core wire. The new wires are flexible stranded core, come in 7 colors and various lengths. The ends have molded tips so they are easy to grip and strong points – perfect for breadboarding and other jumpering needs. We include a bundle of 75 wires with 50 short (100mm/6″), 5 medium, 5 long and 5 xtra long jumpers. Pick up an Arduino starter pack kit today!
I’ve got the MeggySynth synchronized with an Arduino Waveshield, which has been preloaded with some slices of the Amen break. The MeggySynth is communicating via serial port with the Waveshield, and is triggering samples to be played on the Waveshield. The pattern is stored on the Meggy itself, since the Waveshield is sorely lacking in free ROM/RAM. Synchronization is still a little wonky. But I kind of like the stuttering sound. Other samples (like simple kicks and snares) sound better, but less interesting.
Adding quality audio to an electronic project is surprisingly difficult. Here is a shield for Arduinos that solves this problem. It can play up to 22KHz, 12bit uncompressed audio files of any length. It’s low cost, available as an easy-to-make kit. It has an onboard DAC, filter and op-amp for high quality output. Audio files are read off of an SD/MMC card, which are available at nearly any store. Volume can be controlled with the onboard thumbwheel potentiometer.
This shield is a kit, and comes with all parts you need to build it. Arduino, SD card, tools, speaker and headphones are not included. It is fairly easy to construct and anyone with a successful soldering project under their belt should be able to build it.
The shield comes with an Arduino library for easy use; simply drag uncompressed wave files onto the SD card and plug it in. Then use the library to play audio when buttons are pressed, or when a sensor goes off, or when serial data is received, etc. Audio is played asynchronously as an interrupt, so the Arduino can perform tasks while the audio is playing.
Can play any uncompressed 22KHz, 16bit, mono Wave (.wav) files of any size. While it isnt CD quality, it is certainly good enough to play music, have spoken word, or audio effects. Check out the demo video/audio at the webpage
Output is mono, into L and R channels, standard 3.5mm headphone jack and a connection for a speaker that is switched on when the headphones are unplugged
Files are read off of a FAT16-formatted SD/MMC card
Included library and examples makes playing audio easy
Please note that the library is rather bulky, requiring 10K of flash and more than 1/2 K of RAM for buffering audio. It works fine using an ATmega168-based Arduino (or compatible) but for more complex projects I strongly recommend upgrading to an ATmega328!
More information, including design notes, schematics, library, examples, etc is at the Wave Shield webpage.
Foofers (the Dragon?) makes scaley costumes and has designed a “rar-box” based on a Arduino + Wave shield to play special effects. When the button-pad is pressed, different sounds are played through a speaker fitted into the mask. A bit late for his halloween, but a good idea for any costume that could use some extra-yiffy-spiffyness. Check out video and details on his livejournal
Running out of space in your big Arduino project? Good news! Finally, after months of backorders, one can now buy the latest improvement to the ‘ATmega8′ line of chips: the ATmega328’s.
The ‘328 has 32K of flash, and 2K of SRAM. Basically its got the capacity of an ATmega32 but in a slimmer package. These chips are notable for their ability to drop-in replace the ATmega168. So that means if you have an Arduino or compatible clone, it is a easy 2 minute swap.
If you have an Adafruit wave shield or GPS/datalogging shield, and you’re annoyed that the FAT16 libraries eats up so much flash and RAM, upgrading will definitely fix the problem.
I’ve merged my previous updates to the Arduino bootloader to the most recent release and also fixed 2 annoying bugs that have prevailed this long. (1. the missing signature bytes when using the bootloader directly and 2. the broken EEPROM code). Download the ‘328-compatible bootloader files here.
Printable catalog (PDF)
