Thank you for your responses. One small correction regarding the size of the sd card. It's a 16 gb card on which I've created a 2gb partition.Here are the pictures of the module, the arduino's digital pins in use and a picture depicting 5v and 3.3v supply to sd card module going from arduino. http://imgur.com/a/dmR4YAnd I'm not sure about the level shifters/converts. Can you find that out by looking at the pictures?I can try out formatting using the tool that you gave a link to. is it causing problem?I haven't worked a lot on Arduinos but know a bit about electronics, any help will be greatly appreciated.
Thanks for the elaborate explanation. I can try it out on Monday after getting my hands on the hex buffer you suggested. Is there another workaround that I can try in the meanwhile? Otherwise I'll have to wait for two days. Guess I'm getting impatient but just asking if there's a possibility.Thanks anyway, you rock!
Someone said yesterday that I should use a 74HC4050, but when I looked at the CD4050 datasheet this seems well within it's specs, so I don't intend to change.
he 74HC4050 provides six non-inverting buffers with a modified input protection structure, which has no diode connected to Vcc. Input voltages of up to 15 V may therefore be used.
I think the problem is that early CD4050 parts had classic ESD protection with a diode to Vcc. The input voltage is limited to Vcc + 0.5. For Vcc of 3.3V the allowed input voltage is too low for a 5V system.These may appear to work OK by either dragging down input signals and/or raising 3.3V somewhat. The signals are reduced by at least some.Modern CD4050B parts have ESD without the diode to Vcc. Some old style parts and parts in the LV family still are around. See this.The 74HC4050 always works.
Ah, right, that explains it. But are there many early CD4050s still around?The ones I'm using are fairly recent, CD4050B, bought from a large dealer, (RS Components). They have a large turnover, so are unlikely to be selling early CD4050 versions of this chip. The datasheet says 15V max on the inputs, and also says that the input voltage can exceed the supply voltage. On top of that, in that same datasheet the internal schematic for the CD4050 shows a single input protection diode from ground to the input with a reverse-breakdown voltage of 30V.Still something to beware of though.In the other thread, I asked pito to elaborate, but he didn't seem to want to. I also asked for links to threads discussing why CD4050s shouldn't be used, but haven't had a reply yet. I guessed it must have been related to their current sink/source capabilities.The other option besides 74HC4050 and CD4050B would be CD4504B level converters. They're a dual-supply CMOS chip designed for the purpose.So, @umarshehzad, now that I'm better informed on this, if you use CD4050 chips for this, make sure they're the "B" version, (CD4050B), and not the earlier CD4050 (no "B").And @fat16lib, thank you for filling me in on this. (From now on I'll make sure I say CD4050B, not just CD4050.)This is from the CD4050B datasheet:-Price aside, the advantage of CD4050B chips is that they're much easier to get hold of. Not so many suppliers sell 74HC4050s.For example, here in Australia neither of our most common suppliers, Altronics or Jaycar, sell 74HC4050 but both sell CD4050B chips, or at least they did the last time I looked.
Hi,I've used a CD4050BE on MOSI SCK and CS pins and it has worked like a charm. You're a life saver.Thank you very much!
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