While I currently have mostly USB mini cables and devices the clear preference of mass produced consumer electronics is for USB micro for OTG etc.
Do you think it is sensible to scrap barrel jacks in favor of USB micro for power?
I might not do this right away as I have a back log of both barrel and mini USB jack parts. But it seems the way to go forward, just to stock one part Micro A/B jack for powering projects and input.
I have written a bluetooth application for Android that will be useful to people I think but it could use some other testing beyond what I can do in particular I only have one phone to try it on (no issues).
You would need a bluetooth radio capable of serial port profile (SPP) and a device that runs Android 2.1 or later.
I'd like a tester so that I can be sure the application works before wide release/publication, because I'd hate to have a world of hate from some bug I didn't catch dumped on it.
Just PM me if you are willing to help out! (If you know how to sideload an app and can connect your bluetooth SPP device to a terminal it should take about 5 mins beyond that to test the application).
Edit: PS the application will be open sourced when it is released in a month or so.
So I ordered some OLED display which I can't find an FPC ribbon connector for. 0.65 mm contact pitch on the ribbon with 15 positions...
Are the ribbons made Kapton or similar? That is what they look like to me. I am just wondering if soldering directly to the display ribbon is a good option.
Let's say the speed of sound in the object is 5000 m/s...
You strike a disc of material with 3 sensors that can transduce the sound.
The distance to the sensors is 10.1 cm, 9.9 cm and 10 cm. So the arrival time is 0.2 us per mm traveled.
When the sensor detects the sound it will produce an AC voltage which can trigger be triggered off of (compare + RC hold).
Basically the timing spec seems to be easy to meet, so with 3 sensors you should be able to resolve where you struck the disc to 1 mm accuracy. As long as you can sample 3 channels ever 200 ns. Agree? Good.
However these "sound" transducers need to have a size comparable to the resolution of the plate. Also they have to have a "rise time" that is fast enough to measure sound arrival. (You can think slew rate if you like, this might rule mics)
My question is what type of sensor (part number included if possible) do you think would be best?
You could do it optically with lasers and mirrors (very accurate but delicate). Maybe with shock sensors or accelerometers (piezos/mems; might not work for small shocks). Microphones (might not be small enough).
I am just wondering what everyone's favorite displays to use and where they get them from is.
I would love to find a good inexpensive source of VFDs but sadly no. I tend to just get LCDs from Sure or similar off eBay, for most of my display purposes.
I just wanted to let you guy's know that a limited number of my basicUART will be available on ~ March 26th. The cost will be 12 dollars. (Shipping 1 dollar to the US).
It was built as a USB UART for the Eridani board. It doesn't try to be a breakout board like the MCP2200 board Ian made, it just is to replace the FTDI Basic from Sparkfun.
There are a limited number available so I thought I would give you all first dibs (PM or comment first come first serve). I will admit they are a bit ugly as they were done without a stencil, but I check them all to make sure they work.
Verses the MCP2000 breakout, this board has 3.3 V I/O and rail power, uses a ceramic resonator to save money/reduce part count, does not break out the GPIOs...
I know a lot of folks use Eagle here including Ian I think, but hope some of you will give KiCAD a try.
It is a bit different than Eagle, but I like several things it does more than how Eagle works. More over there are no limits on how many schematic sheets you can have or how big the board can be. There is an autorouter that is web based that gives very nice results, and most SMD parts have footprints (modules) already so you mostly just need to give labels to parts.
When I was learning KiCAD I didn't really like the tutorials I found, so I wrote one... I don't know how much better it is than the existing ones but here it is:
I think it is a good idea. I have lots of parts from projects I keep around but probably won't use kind of thing. Trading without money exchange seems a good idea. Although matching is hard. Who knows just thought I would put it out there.
I know that MSP430 is known for its low power consumption, and I have read datasheets but in terms of practical implementation can anyone tell me if the MSP430 is far far better than the other micros or is the difference not all that dramatic?
There were a ton of great ideas. I wish I could give away more than 2 boards but I am afraid I cannot afford that. If you are one of the people I did not select I hope you will considering purchasing one if it suits your needs at: http://teholabs.com
The 2 free boards are going to: phirephly for his project to try to implement Codec2 on an ARM alextm for his SSH over USB project as a physical means to help secure his system
I have been thinking of this for a long time. XBEEs are great but there are a TON of applications where all you want is to flip a switch with RF.
It would be nice to have a transceiver rather than just a receiver (for state check and for acknowledge of packet etc).
The data rate could be 8 bps for all I care...
The cheapest radios I know of are SPI 900 MHz ones: SI4420 MRF49XA
Even with a 0.50 microcontroller that is a lot more than I think this should be.
Anyone know of a less expensive radio method, perhaps it doesn't have to be some FSK chip. Don't suggest the Hertz experiment. I want something that would pass muster with the FCC.
The 2.4 GHz radios have cheaper chip antennas but the ICs are more again for full FSK radios.
One project I keep thinking of working on is some simple VGA/DVI/HDMI output adapter for embedded systems.
The need for it is large. You can large LCD display for like 100 dollars but a tiny LCD often will cost you more. I bet lots of hackers have old smaller LCDs just laying around.
To make it cost effective it probably should use fast SDRAM or DDR with some FPGA or CPLD doing the logic for SPI. Basically I would have like some I/O pin set switch between what buffer to display and which to fill with data, plus a pin to say if it is command or data. You would need commands for switching refresh rates. I thought about trying this project with a pure microcontroller approach but the clock rate you need is rather high actually. There are some implementations out there that do low resolution for the hobby market but nothing high resolution.
Some chip out there might do it, after all digital cameras have HDMI on them now. I kind of think HDMI might be the way to go as it would open up all sorts of set top like devices that do all sorts of neat things for people in their home without a computer.
I just put the finishing touches on a development board for Luminary Micro's LM3S3651 chip. Luminary is now part of Ti. I love the peripheral library that comes with them it makes them really easy to use, particularly for ARM microcontrollers.
Basically I designed the board with USB Host or Dev applications in mind mainly. Mostly I wanted something that could do hosting of power hungry USB devices (like hard drives), but it is good for much more than that.
It is Cortex M3 128 KB Flash, 32 KB SRAM, 50 MHz, 29 GPIOs, SPI, UART, I2C etc.
Anyway I just wanted to start a thread for anyone who needs help using it. Though I wrote really comprehensive docs I think: http://teholabs.com/docs/eridani:overview
I go over setting up both serial and JTAG toolchains. I plan on full support for the BusBlaster when it is in good shape.
My next big project is probably going to be this idea, I am just interested in if anyone else here is interested in the concept.
The basic point is a modular very high quality music player for your home.
Basically the structure will be a Cortex M3 with a I2S interface to your choice of DAC backend.
The M3 micro will have a bunch of SDRAM for you to have for scratch decoding space in which is directly accessible in the memory map. For storage it will use FAT on a USB mass storage device. Say a 2.5" hard drive.
The uC I think I will use is a LM3S9B90 but I also might use a LM3S9790 for this project.
These have built in Ethernet but given the 12 MBit rate of USB Full-Speed to the mass storage I don't know if that is really the best transfer means, probably a pull the disc add files scheme is better.
The project may have a daughter board for the user interface/display to let people choose the display they want to use. This way if someone wants to do touch they could or what have you. My inclination is for VFD + a few buttons and a rotary encoder.
My codec priorities are: WAV FLAC OGG anything else
I don't think there will be MP3 support for licensing reasons, some sort of computer side transcode might be the best workaround for large MP3 collections, but as the point of this is HiFi hopefully the sources are better than average MP3s anyway...
The first DAC backend I have planned is WM8740 based.
