Adafruit's Trinket • Hacker News Board

Re: Adafruit's Trinket

#41

Post by jwatte » Sat, Sep 07, 2013, 3:59 PM UTC

IgorPartola wrote: post #4

Or for $10, you could get the TI MSP430 LaunchPad [1]. You can then pop off the DIP chip and mount it however you want. It is nice since the chips themselves are about $1 or so each (depending on which one you get). [1] http://www.ti.com/ww/en/launchpad/msp430_head.html

An ATTiny85 in DIP also runs unassisted. That's not the point of this board, though.

Re: Adafruit's Trinket

#42

Post by jwatte » Sat, Sep 07, 2013, 4:03 PM UTC

Why didn't they use the ATmega 8u2 with native USB? The small version is no bigger than the chip on this trinket. Eating 3 kB for the tinyUSB stack is annoying.

Also, they claim is has "hardware I2C" which is stretching the truth IMO. The USI doesn't let you write a fully interrupt driven I2C slave, it is a polled implementation leaving lots of support logic to software.

Re: Adafruit's Trinket

#43

Post by egfx » Sat, Sep 07, 2013, 6:31 PM UTC

Can I use this to plug into my cars usb and take over the touch screen display unit?

Re: Adafruit's Trinket

#44

Post by adaml_623 » Sat, Sep 07, 2013, 8:45 PM UTC

phunge wrote: post #5

Looks somewhat inspired by the teensy 2.0 (mini USB -- not micro!, bootloader button). This has a lower price point and an ATTiny instead of atmega32u4. I have a few teensys and find them to be really practical. Does the ATTiny implement USB or is it bit-banged?

Good question. The type USB implementation is important. There are lots of things you can't do well if the CPU is managing the USB connection in firmware at the same time as running the implementation.

Re: Adafruit's Trinket

#45

Post by danellis » Sun, Sep 08, 2013, 7:56 PM UTC

I got excited about this thinking I could use it to quickly prototype controlling a toaster oven over USB, but I'd have to add another software USB implementation like the bootloader's.

Re: Adafruit's Trinket

#46

Post by BuildTheRobots » Sun, Sep 08, 2013, 8:33 PM UTC

No one seems to have mentioned the Minimus[1] as an arduino compatible[2] alternative -they we're costing us £3 and have a lot more GPIO pins to play with[3]. The new version is powered by a ATMEGA 32U2 so it's got some grunt (and lets you play USB too).

[1] http://minimususb.com/ [2] https://github.com/pbrook/minimus-arduino/ [3] https://github.com/pbrook/minimus-arduino/wiki#pinouts