This portable sample player packs quite a punch. [Lee] wanted a nice portable way to take his samples with him, but refused to water-down the features just because it is portable. He set of goal of playing between 3-8 simultaneous notes from a large assortment of stored samples.
Sample space was the first design consideration, and it’s hard to beat the price per megabyte of an SD card. After some calculations he concluded that it is possible to pull these samples off the card quickly enough to achieve his simultaneous note goal at CD quality frequencies, but only if there is little or no latency when reading from the card. This means [Lee] needed a fast processor so he chose the LPC1769 which is an ARM Cortex-M3 processor which can run at 120 MHz.
The project box includes room for a volume knob to control the output from the in-build headphone amplifier. There’s also a rotary encoder for selecting sample sets. But we’re a bit confused on this part as the device is MIDI controlled. [Lee] is the creator of the electronic Moolodeon, which itself has MIDI out and will be used as a controller for this project.
Looks like the Lightweight USB Framework for AVRs (LUFA) has just been ported for ARM microcontrollers. NXP recently released a package for their LPC Cortex M3 family of ARM controllers. You won’t find a reference to LUFA on their nxpUSBlib description page (which we think is kind of sad), but if you grab a copy of the beta code the Version.h header file shows that it is indeed a port of the project. This is further backed up by the LUFA creator, [Dean Camera], who consulted with the NXP team doing the work.
The package provides an open-source USB stack that you can use in your projects as a USB host or USB device. We’re advocates of open source packages like this one as it makes it much easier for hobbyists to get help using the tools, and it allows the community to give back through bug fixes and feature additions.
We’ve highlighted a few LUFA projects, like this keyboard remapper and this AVR programmer. We’re looking to seeing the first set of NXP LUFA projects roll through!
Some hard work has gone into making it possible to develop for the STM32 Discovery board using a Linux system. The board boasts an ARM Cortex-M3 processor, which can be programmed via the mini-USB port on the side. But the company only supports development through their IDE’s which don’t run natively on Linux. The stlink project aims to solve this, providing a toolchain, and making it possible to flash the microcontroller via the USB connection.
The github project linked above also includes a tutorial to get you started (pdf). In addition to a walk through on compiling the software packages, it includes a simple blink program that you can use to test out your hardware. GDB, the familiar open-source debugger, is used to flash the chip. This is a bare-bones tutorial so if you end up posting about your experiences using this toolchain with the Discovery boards we’d love to hear about it.
The team at Leaf Labs just released a new library to demonstrate the VGA capabilities of their Maple dev board. Although it’s only a 16 by 18 pixel image, it shows a lot of development over past video implementations on the Maple.
The Maple is a great little Ardunio-compatible board with a strangely familiar IDE. We’ve covered the Maple before. Instead of the somewhat limited AVR, the Maple uses an ARM running at 72MHz, making applications requiring some horsepower or strict timing a lot easier.
We’ve seen a few projects use the increased power, like a guitar effects shield. It’s possible the Maple could be made into a game console that would blow the Uzebox out of the water, but we’re wondering what hackaday readers would use this dev board for.
Watch the video after the jump to see how far the Maple’s VGA capability has come after only a few months, or check out Leaf Lab’s Maple libraries.
Continue reading “VGA out on a Maple board”
As a project for an embedded systems class, [Alan] recently built himself a sunrise-simulating alarm clock. You are probably familiar with these sorts of timepieces – they gradually light up the room to awaken the sleeping individual rather than jarring them awake with a buzzer or the radio. Since many commercial units with this feature are sold for $70 and up, his goal was to replicate the functionality at a fraction of the cost, using only open source components.
An Arm Cortex M3 processor runs the show, displaying the time via a pair of 8×8 LED matrix panels on the front of the device. The clock is programmed to gently wake up its user by simulating a sunrise over a period of 5, 15, 30, 45, or 60 minutes. If the user has not woken up before the sunrise simulation is complete, the clock resorts to a traditional piezo alarm to rouse the heavy sleeper.
The project is nicely done, and after looking at his bill of materials it seems to be far cheaper than many sunrise alarm clocks you will find in stores.
Quadrocopters are all the rage lately, and while we have seen our fair share of large devices, [Arnaud Taffanel, Tobias Antonsson, and Marcus Eliasson] have been dutifully working to buck that trend. Their CrazyFlie is a miniature quadrocopter that uses its PCB as the main structure of the device.
Since the goal was to use a PCB as its frame, the copter’s footprint from the edge of one motor to the other is a modest 8cm, and it weighs in at a measly 20 grams! The entire platform runs on a Cortex-M3 CPU that takes input from an accelerometer and pair of gyroscopes to help keep its balance. Wireless communications are handled via a 2.4Ghz radio transmitter, and the quadrocopter’s power is supplied by a tiny 110 mAh LIPO battery pack scavenged from an R/C plane.
All of the control and telemetry is handled by a PC, which relays control messages it receives from the pilot’s game pad to the CrazyFlie. We’d love to see if they could retain this small footprint if everything was handled by the quadrocopter itself. Either way, this thing rocks – we most definitely want one!
Stick around to see a quick video of their mini quadrocopter in action, and be sure to check out our coverage of U. Penn’s quadrocopter creations if you are interested in seeing more.
Continue reading “Mini quadrocopter is Crazy awesome”
In case you missed it, Texas Instruments sells a little robot called the Evalbot as a development platform for ARM Cortex-M3 microcontrollers. Since its release we’ve seen a few hacks on the hardware; the image above is a proof of concept for developing for the device under Linux. We have criticized TI in the past for not natively supporting Linux with their IDEs. We’re not sure how it will play out, but they have added new software package options to go along with the hardware. You’ll notice on their PR page that there is now an option to use CodeSourcery. It is a trial of the full version, but at least it is a step in the GNU direction from their previous offering.
The Hackaday team has been talking off and on with TI about the hardware. We’re happy to say that they’ve been listening to the Internet community about their likes and dislikes; following various online groups that have sprouted up to talk about Evalbot projects. It sounds like they’re thinking about hosting a contest using the hardware. So maybe you want to get your hands on one so that you can familiarize yourself and hit the ground running if/when that contest starts. You’re in luck, we can help save you a few bucks.
The first time that Texas Instruments tried out a $125-off coupon code the deal got away from them. It had been meant for attendees of the ESC Boston conference. They honored the deals that went through before the proverbial run-on-the-bank got shut down. This time around they’re using serialized deal codes to limit the number of give-aways. We’ve got 200 of them just waiting for our loyal readers to use. One code will let you purchase one Evalbot for just $25 (instead of $150).
Please take a moment to decide if you actually want (and will use) one of these robots, and decide if you are willing to shell out the $25 to order it. You see, we don’t want this deal going to waste.
If you decide this is for you, send an email requesting a code to:We’re all out! We’ll dish out the deal on a first-emailed-first-served basis. We will update this post when all 200 have been claimed.
We will not tolerate anyone gaming the system and so we reserve the right to disqualify any email submission for any reason in an attempt to maintain some semblance of fairness. Also… if you’re planning to pick this up just to resell it for cash you’re a loser.
[update: Those who emailed us requesting a code should begin receiving replies this evening or tomorrow.]
[Update 2: here is the specific bot you should be trying to buy. ]