Back
[11:31:00] <_ami_> i am making a joystick game pad using v-usb interface. I am using attiny85. Since ports are less so i am thinking of using shift registers instead for reading inputs from gamepad.
[11:31:26] <_ami_> reading from shift registers won't be that slow?
[11:31:39] <_ami_> has anybody experimented before?
[11:32:53] <Casper> shift is slower than direct reading, but it depend on what speed you read it
[11:33:05] <Casper> it may be quite insignificant
[11:33:38] <Casper> I beleive the nes did used a shift register
[11:34:03] <Casper> or atleast.. it was simmilar (serial communication))))))))))
[11:35:34] <LeoNerd> _ami_: You might like to use an I²C chip like the PCF8574
[11:35:58] <LeoNerd> I²C only needs two IO pins, whereas SPI would need -atleast- 3 and in practice I've never found an SPI-compatible shift register for -reading- parallel inputs
[11:36:15] <LeoNerd> But really, you want to use something like a 16U2 or U4. Plenty of GPIO pins and talks USB natively
[11:40:38] <skz81> _ami_1, for a joystick i guess I will do with no problem ! I²C can go up to 400KHz IIRC. If you send your data on USB @40Hz, it is more than needed I guess :)
[11:41:25] <skz81> <LeoNerd> But really, you want to use something like >> Maybe he choosed the hard way to learn something ?
[11:54:34] <_ami_1> thanks guys! :)
[11:58:09] <_ami_1> 74HC165 should work fine?
[11:58:42] <LeoNerd> Nop
[11:59:16] <LeoNerd> '165 isn't SPI'able for two reasons. 1: its MISO line doesn't hiZ - though in a single-slave scenario that likely doesn't matter; 2: it doesn't have a convenient SS line
[12:00:09] <LeoNerd> You -can- turn it SPI-capable if you add some buffer chips and whatnot around it, but by that point it would be easier/nicer/cheaper/smaller to start from a sensible MCU in the first place
[12:00:27] <_ami_1> ok, made a note of it.
[12:00:32] <_ami_1> thank you.
[12:51:56] <xa0z> theBear, I've bought Tom's USB programmers in the past, but this one isn't one of his.
[13:31:27] <theBear> the umm, i thought i was helping someone specifically looking for details of his, but so long as you happy
[13:31:46] <theBear> or not, that's not on my perogative-list today
[14:45:12] <inkjetunito> good evening
[14:46:40] <inkjetunito> on a tiny85, are the cpu clock and i/o effectively running at the same frequency?
[14:46:47] <inkjetunito> *i/o clock
[15:02:57] <LeoNerd> Yes
[15:08:53] <inkjetunito> ty
[15:56:03] <liwakura> i recently bought some atmega328-PU
[15:56:14] <liwakura> whats their difference to the atmega328-P ?
[15:56:59] <liwakura> *atmega328p bs atmega328-pu
[15:58:56] <LeoNerd> Nothing
[15:59:03] <LeoNerd> The final letter gives the package format
[15:59:18] <liwakura> package like DIP-28 or sth?
[15:59:21] <LeoNerd> The chip wafer inside the package is an ATmega328P; the trailing U says what package it's in
[15:59:35] <LeoNerd> Yah.. I /think/ the U is a QFP32 but I'd have to doublecheck on the datasheet
[16:00:51] <liwakura> i have atmega328p in a QFP32 (arduino nano)
[16:01:05] <liwakura> and the atmega328-pu is an DIP with 28 pins
[16:01:17] <liwakura> still confused about the dash positioning
[16:01:32] <liwakura> wait
[16:01:38] <LeoNerd> Is this on eBay?
[16:01:42] <liwakura> the DIP-28 says atmega328P-PU
[16:01:50] <liwakura> no, i have them physically here
[16:02:19] <LeoNerd> Ohright...
[16:02:34] <LeoNerd> I remember now... the 328-PU is the DIP28-packaged version of the 328 (noP) wafer
[16:02:42] <LeoNerd> The 328P-PU is a 328P wafer
[16:02:49] <LeoNerd> /that/ P stands for "picoPower"
[16:03:05] <liwakura> ah
[16:03:19] <liwakura> and the other P with the U just stands for the DIP28 ?
[16:04:00] <LeoNerd> So it seems
[16:04:09] <liwakura> okay
[16:04:16] <LeoNerd> The other letter to be aware of is the letter 'A'
[16:04:27] <liwakura> what does it do?
[16:04:55] <LeoNerd> Again the dash matters; there's minor variations like the tiny84 vs. tiny84A (which are really just process changes, alters some timing parameters, power usage, but generally same chip); vs the -AU package specifier
[16:05:17] <liwakura> lets ignore the package specifiers from now on
[16:05:22] <liwakura> what does the A do?
[16:05:28] <LeoNerd> It's a version stepping
[16:05:40] <LeoNerd> tiny84A is a small update to the tiny84, etc etc...
[16:05:40] <liwakura> i head that the B enabled PORTE on the two analog-only pins
[16:05:47] <liwakura> *heard
[16:05:56] <LeoNerd> Well, that's specifically the mega328PB, yes.
[16:06:13] <LeoNerd> In general, a trailing A or (as it now seems) B on an AVR part number just means a version stepping
[16:06:20] <LeoNerd> Exactly what that means will depend on the chip itself
[16:08:42] <liwakura> nice to know.
[17:16:22] <Lambda-Aurigae> well, it's official. Atmel newsletter is now advertising shit for microchip.
[17:16:43] <Tom_itx> there goes the neighborhood
[19:22:55] <inflex> aw feck
[19:23:16] <inflex> at least the AVRs should run for a few more years.
[19:23:23] <inflex> (Tiny and mega series)
[19:25:25] <Lambda-Aurigae> tinyPIC and megaPIC!
[20:45:23] <rue_house> yea, I'm learning how to use arms
[20:45:25] <rue_house> stm32
[23:15:48] <_ami_> which are the companies which uses AVR in their products?
[23:16:19] <Casper> lots of them do, like your xbox controller
[23:16:59] <_ami_> aha, nice, good to know that. i used xbox before so it feels good that avr is used there. :)
[23:17:55] <_ami_> so job opportunities are there in market for AVR programmers
[23:18:41] <Casper> currently, the future is bluried, atmel got bought by microchip (which make PIC), so it is possible that they kill the avr line...
[23:19:52] <_ami_> oh boy!
[23:20:31] <_ami_> i knew abt atmel bought by microchip but hopeful that avr will not be killed.
[23:20:42] <_ami_> but you never know
[23:22:13] <Casper> if they are bright, they would try to make a mix of the 2, and make a greater product...
[23:22:29] <Casper> ... but you know how it goes: buy the competitor, kill the line..
[23:22:54] <_ami_> :/