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funkathustra

Member Since: October 18, 2009

Country: United States

  • I totally agree. If you’re measuring AC line voltage currents, I wouldn’t recommend using this PCB – the layout is downright dangerous. Whoever designed this board has obviously never done any mains voltage designs before, as this violates every creepage/clearance rule I’ve ever seen.

  • It’s Linux, so of course you could do that – but since it’s an embedded platform, you’d typically just compile your custom app on your big, fast computer and deploy it with scp/sftp, debugging with gdb. Most IDEs make this operation seamless.

  • All modern ICs are 1.8V compliant, and generally have lower power consumption when operated at that voltage. It’s time to throw away your 1980s CD-series logic chips and move into this century.

  • It’s not a matter of speed, it’s a matter of interfacing. The processor doesn’t have a serial or parallel camera interface block on the chip, so you can’t interface an image sensor to it without an external FPGA/CPLD.

  • I totally don’t see any advantage of an SD card form-factor versus this. It’s about the same size, and what’s the difference between putting an SD connector on a board or a 70-pin Hirose, other than the fact that you get a ton more I/O with this option?

    I’m really glad they ditched the SD form factor.

  • While LiPo batteries have a voltage of roughly 2.5 to 4.2V, they drop off fairly quickly after they hit 3.5V, which means using this part in a 3.3V project will run the converter in the extremely inefficient (~75%) step-down region for most of the time. Consequently, I wouldn’t recommend using this part for 3.3V projects that are LiPo-powered.

    Most designs I’ve seen actually just use a buck converter to step-down the voltage – when the battery voltage drops below 3.3V, the converter will track the input voltage. This may seem counter-intuitive, since you don’t “squeeze out” all the juice in the battery – however, the increased efficiency of the buck solution means you get longer battery life overall.

    One article I read indicates at 300 mA output current, a buck converter got 9 more minutes of battery life than a buck-boost converter of similar configuration: http://www.eetimes.com/document.asp?doc_id=1273123&page_number=3

    Obviously, if you’re building something with ultracaps or other low-voltage stuff with UVLO disabled, this is a great part to use. And it definitely shines at 5V output – I’d just stay away from using it in a 3.3V configuration with LiPo batteries.

  • While LiPo batteries have a voltage of roughly 2.5 to 4.2V, they drop off fairly quickly after they hit 3.5V, which means using this part in a 3.3V project will run the converter in the extremely inefficient (~75%) step-down region for most of the time. Consequently, I wouldn’t recommend using this part for 3.3V projects that are LiPo-powered.

    Most designs I’ve seen actually just use a buck converter to step-down the voltage – when the battery voltage drops below 3.3V, the converter will track the input voltage. This may seem counter-intuitive, since you don’t “squeeze out” all the juice in the battery – however, the increased efficiency of the buck solution means you get longer battery life overall.

    One article I read indicates at 300 mA output current, a buck converter got 9 more minutes of battery life than a buck-boost converter of similar configuration: http://www.eetimes.com/document.asp?doc_id=1273123&page_number=3

    Obviously, if you’re building something with ultracaps or other low-voltage stuff with UVLO disabled, this is a great part to use. And it definitely shines at 5V output – I’d just stay away from using it in a 3.3V configuration with LiPo batteries.

  • Yay! Only 50% more expensive than from DigiKey!

  • The clock signal is obviously constant, but it’d have to be synchronized by looking at the sync pulse embedded in the component video signal. You’d also have to do some math somewhere to convert the color space of the component video signal (which is YPbPr) to RGB. And you’d still have to generate the HSYNC/VSYNC signals based on the front/back porch of the display.

    That’s a lot of work to go through to end up with something that’s not going to work nearly as well as an off-the-shelf 4.3" monitor with an analog input (something you can most certainly buy off eBay).

  • Total lost cause. Just buy a 4.3" LCD monitor with a composite input off eBay. This product is just a “dumb” LCD. You’ll need a controller configured specifically to drive this display with the proper front/back porch timings, pixel clock, and obviously resolution.

No public wish lists :(