If your next project needs the ability to play MP3s but you don’t have a lot of room to spare in your enclosure, [Boris] has just the thing you need. His tiny embedded MP3 module supports playback of up to 65,536 songs or as many as you can fit on a 16GB microSD card, which isn’t bad in the least.
The module relies on a PIC24F for input and control, while a VS1011 handles all of the MP3 decoding responsibilities. He says that the module would be great for voice-enabled vending machines, telephone systems, cars, and more.
With such a wide range of possible applications, he decided that the module should be able to support several different input methods. The board can be controlled via a set of digital input buttons, which is perfect for direct human interaction, while it also supports serial control for scenarios where it is part of a larger embedded system.
Of course, we’ve seen tiny MP3 players like this before, but we like the fact that this module was designed to operate in standalone mode or as a component in a larger device. Of course all of the device’s schematics, code, and a BoM are available, allowing you to build your own if you are comfortable with SMD soldering.
Everything gets smaller as technology improves. [Rossum] reduced the space needed for an Atari 810 disk drive by building this tiny replacement. Of course it doesn’t use floppy disks, but takes a microSD card instead. And it doesn’t stand in the place of one floppy drive, but can emulate up to eight different drives. The best part is that [Rossum] went to the trouble of designing an enclosure and having it fabricated via 3D printing in order to look just like a doll house version of the original hardware. It uses an LPC1114 ARM Cortex-M0 microprocessor to translate data transmissions to and from the Atari hardware, storing it on the 8 GB card.
As usual, you’ll soon find the schematic, board artwork, and code up on his git repository soon.
[Dmitry Gr.] built a simple circuit to playback digital audio. At the center you can see an 8-pin PIC 12F1840 microcontroller. It’s pulling audio data from a microSD card which is read through a full-sized SD card adapter to which he soldered jumper wires for all of the necessary connections. There is one additional semiconductor, a FET which is used to drive the speaker seen to the left. Unregulated power is provided by a pair of AA batteries (four are seen in the picture above but only two are actually connected to the circuit). He’s planning to post his code package soon, but for now you’ll have to be satisfied with a couple of demo videos and a schematic. Both videos are embedded after the break, and we’ve also included a screenshot of the schematic which is shown in the second video.
This is very similar to the 1-Bit Symphony CD we saw almost a year ago in a links post. That one used a jewel case instead of the protoboard seen here, and had a headphone jack instead of the speaker.
Continue reading “Single-chip Digital Audio Player”
[Nick] over at Gadget Gangster has a new version of his prototyping hardware for Propeller microcontrollers, called the Propeller Platform USB. A little more than a year ago we looked at the last version which was larger, used a DIP processor, and came unassembled. The new version does come assembled because of the migration to surface mount components (which may take some of the fun out of it if you just love soldering kits). This not only reduces the board footprint, but makes room for more goodies. As the name implies, there’s now a mini-USB socket with a USB to UART bridge, a microSD card slot as been added, and the onboard EEPROM has been doubled. This is a nice hardware upgrade but the price has been upgraded by $25 as well. No worries, it’s open source so you can roll your own if you have the parts on hand.
OpenMoko, the company behind the FreeRunner open-source phone, released their latest product today: WikiReader. It’s a small mobile device for browsing Wikipedia. Rather than use a wireless network to pull data off of the web, it has local copy of the database on a 8GB microSD card. This approach has been used before, and it lets the WikiReader be compact and really cheap. It uses a Kindle-esque touch-screen display that allows it to run on 3 AAA’s for about a year. The device itself costs just $99, but you can choose to receive updates by snail mail for just $29/year. Alternatively, you can just download the +4GB file and dump it on the card.
Like the FreeRunner, this project is also open-source. The code isn’t available yet, but they say it will be released soon. With luck, the device will be really easy to hack.
[Hunter Davis] keeps rolling out the hacks for the Zipit. In the past he showed us how to run DOSbox, and then how to get NES emulation working on this tiny device. Now he’s got Linux kernel 2.6.29 running Fluxbox with mouse (newly added), audio, and WiFi functionality. Follow his step-by-step flashing instructions to load the kernel into the Zipit. Once flashed, a partitioned microSD card servers as the filesystem and swap.
Who needs a 10.1 inch screen or an Atom processor when you can get this 2.8″ QVGA beauty with an XScale processor for around $40?
SD cards add cheap persistent memory to your project, but the holder takes a lot of board space. A smaller option is the microSD flash format. MicroSD cards are compatible with regular SD cards, and most come with a free adapter. We looked at four holders for our mini web server. Which should you choose? Read about our experience below. Continue reading “Parts: MicroSD Memory Card Holders”