A couple of weeks ago we put up a post titled Addressing Microchip’s open source problem where we talked about some of their shortcomings as far as open source code goes, specifically the TCP/IP stack and the USB stack. The comments were predictably fairly negative. The interesting part here is that Microchip actually listened. If you read through all of the comments, you will get a bit of an inside look at what is going on internally at Microchip. At the very end, [Marc] from Microchip left a couple of comments outlining a pair of prizes for independently ported stacks for TCP/IP and USB. Microchip can’t fully open the ones that they have because of legal reasons so they need the help of the development community and they are putting up $1000 for each one to prove that they are serious. If you follow this link you will arrive at a page outlining the rules for the contest.
The gauntlet has been dropped! Do you have chops to pull this off and earn yourself a cool $1000?
[John Thomson] usually keeps his phone on vibrate when it’s in his pocket, and he often forgets to turn the ringer back on when setting it down to charge. This typically results in a bunch of missed calls in the meantime, so he had to devise a way to counteract his forgetfulness.
You might remember [John] from the Santa-pede contest we held last December. He wanted to try his hand at yet another competition, the Avnet Dog Days of Summer contest, so he scrambled to come up with a quick fix for his situation. He concocted a simple circuit based on [ChaN’s] design for a “Simple SD Audio Player with an 8-pin IC” that would alert him to incoming calls, even when his phone was on vibrate.
[John] used an ATtiny85, just as [ChaN] did, adding a speaker for sound output and a piezo sensor to detect his phone’s vibrations. When the piezo senses a bit of motion, the audio player kicks in, blaring a series of sounds that are sure to get [John’s] attention.
For his A-level electronic course work, [Andrew] decided to build a digital sound recorder that doesn’t use a microcontroller.
[Andrew]’s build captures audio from an on board microphone at 8000 samples/second. The audio is digitized into 8-bit sound data and sent to an SRAM. The recording and playback functions are controlled entirely by 4000-series logic chips. He admits the sound quality is pretty poor; this is mostly due to the 8kHz sample rate. In some circles, though, a terrible sample rate is seen as being pretty cool so we’re not going to say [Andrew]’s build is useless.
There’s some pretty smart design choices in [Andrew]’s build, like a cut off filter on the microphone set at 4000 Hz (the Nyquist frequency of his system). For the recording medium, he used an SRAM that can hold about half a megabyte of data. At 8000 samples/second, [Andrew]’s build can store a little more than 60 seconds of audio. The build may not be a logic chip computer, but there’s not any question in our mind that [Andrew] learned something. Check out [Andrew]’s 66-page coursework report here (PDF warning).