<nicksydney>
wpwrak: was looking at y-box schematics http://downloads.qi-hardware.com/people/werner/anelok/tmp/ybox-draft-20140116.pdf .. can you tell me please why the CON2 GND is connected to VBUS from CON3 and VBUS from CON2 connected to GND of CON3 .... I thought it should be GND - GND and VBUS to VBUS ? sorry bit lost here :)
<wpwrak>
urgh
<roh>
d- and d+ get swapped too
<roh>
the connector is pinned reverse or so
<wpwrak>
seems that some idiot forgot to flip the thing
<roh>
nice find nick
<nicksydney>
wpwrak: *whew* sorry I thought there is a reason behind the switching of those 2 as I'm still new in this kind of things so was not sure whether it's my understanding :)
<nicksydney>
roh: thanks
<roh>
thats what review is all about! :)
<roh>
somebody learns something, and somebody doesnt fry his usb device ;)
<wpwrak>
actually .. lemme check whether the schematics symbol is correct ...
<wpwrak>
the shield shouldn't float. not sure if just connecting all the shields is ideal but it can't be entirely wrong either
<wpwrak>
symbol looks right. so the routing is indeed wrong
<wpwrak>
nicksydney: thanks a lot ! that saved me some future headache :)
<wpwrak>
will fix it later. gotta run now.
<nicksydney>
wpwrak: no worries....thanks for sharing the schematics it helped me also to learn a number of things of connecting USBs together :)
<nicksydney>
wpwrak: for CC2543 how do you begin in determining what components to connect to which pin when you start designing this ? do you go through and read everything that is in the datasheet ? or there is something like a reference template that is provided by the chip vendor
<nicksydney>
I was thinking if we want to start designing something with a new chip reading through datasheet for someone like me is going to be a nightmare as surely I won't be able to understand all the detail technical specs that is listed inside the datasheet so interested to know what are the normal steps that you take
<nicksydney>
it's so cool..that the discrete components that TI normally used now sits nicely and pretty in 1 single 'small' chip http://ctrlv.in/284144
<nicksydney>
wpwrak: another question...looking through CC2543 datasheet pg 21 under the 'Application Information' section pin 18 is connect to GND while y-box is to 3v3 ... and pin 23 and 24 connect to 3v3 with 220pF and 100nF while datasheet connect pin 23,24 and 29 straight to power (2-3.6v) ?
<nicksydney>
sorry too many questions :)
<nicksydney>
boy oh boy..CC2543 is not cheap eh...digikey selling them for over $6/piece :(
<nicksydney>
DocScrutinizer05: just removed all the unnecessary parts that we don't need :)
<nicksydney>
DocScrutinizer05: Neo900 has got Barometer/thermometer ... is the thermometer can be use to measure body temperature too ?
<wpwrak>
nicksydney: (selecting cc2543 pins) well, first i have a look at what functions are in the chip. then i select the ones i need. e.g., UART in SPI mode for SPI and a timer output for the clock that goes to the KL25
<wpwrak>
then there are often various pins one can select for one function. so i try to pick something that looks low on conflicts and where the order of signals on both ends matches
<wpwrak>
this is just heuristics. sometimes i find that my choice wasn't all that great and i reassign them later on
<nicksydney>
what you mean by "looks low on conflicts and where the order of signals on both ends matches" ?
<wpwrak>
"low on conflicts" = not in an area where lots of things come together (if i have a choice)
<wpwrak>
"order of signals" = if chip 1 needs to talk to chip 2 and chip 1 has the signals A B C D in this fixed order but i can configure different orders for chip 2, then i should try to find something close to A B C D as well
<wpwrak>
else i have a lot of crossed signals
<nicksydney>
the signals A B C D you are referring to is SPI et al ?
<wpwrak>
(L252) yes, that's the matching/tuning circuit. their LC combination is a bit unusual. but i guess they know what they do :)
<wpwrak>
the values in the tuning/matching circuit depend on lots of hard to calculate factors. sometimes you don't need anything. so it's all trial and error. for the prototype, i don't plan on making a lot of RF optimization experiments. but i include space for the components in the circuit, so that it can be tuned if needed.
<wpwrak>
(pin 18) that looks like a bug in TI's schematics ;-)
<wpwrak>
(other pins) note the fine print in the data sheet: "Power Supply Decoupling Capacitors are Not Shown"
<nicksydney>
(pin 18)..how do you deduce it's a bug ? is it because the pin is labelled VDD so it should not be to GND ?
<wpwrak>
in anelok/anelok, run dsv ccsch
<wpwrak>
that's their reference circuit. that's the one i used as a basis for power. and it has pin 18 ad VDD,
<wpwrak>
like the data sheet does almost everywhere. but yes, it's a not very nice bug in ti's documentation.
<wpwrak>
(signals A B C D) yes. SPI has lots of them, and the order often has slight variations
<nicksydney>
(dsv) no data sheet found for "ccsch" ?
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<wpwrak>
nicksydney: (flip-chip) means it's damnably small ;-)
<wpwrak>
nicksydney: cut ... but the prices are evil
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<wpwrak>
#s/cut/cute/ # that was typed at resting caffeine levels ...
<nicksydney>
yeah the price is evil !
<nicksydney>
but nevertheless the idea is really interesting..wish someone will make it more cheaper say like $10 / piece
<wpwrak>
i guess there ought to be something on aliexpress ... ;-)
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<nicksydney>
wpwrak: nah nothing there has looked around :)
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<DocScrutinizer05>
nicksydney: no
<DocScrutinizer05>
it probably is even useless to probe ambient temperature
<nicksydney>
DocScrutinizer05: was thinking if we strip off all the unneeded features of Neo900 it can be used something like the cloudphone project...probably add some other stuff like heart-rate sensors, temp sensor :)
<nicksydney>
oh well it was just a thought :)
<DocScrutinizer05>
I don't like clouds
<wpwrak>
let's not forget penis size. this information is essential for targeted marketing :)