Teensy++ $24 AVR board, USB, 63/4/2KiB flash/RAM/EEPROM, 46 I/O, 8 analo., 9 PWM | Hacker News Reader

O, 8 analo., 9 PWM

pjrc.com

84 pointsralph19 comments

A very nice development. I like the AT90USB162 for its native USB interface (no serial unless you build it). I find this makes the code for host communication cleaner as it dispenses with serial parsing and all the error handling that comes with it. The lack of analog inputs hurts on the '162. Even for nominally digital applications, I find it handy to use the analog inputs for things like instrumenting currents and secondary voltages.

For the folks mystified by Arduino popularity this may be your preferred solution (lower cost, more capability). My personal opinion is that Arduino is not popular because of the hardware or software, but because of the culture. It is deliberately kept accessible to people that don't know fancy words like "data direction register". You can look at the examples, do a little copy and paste, make some breadboard connections and build that special little object that you thought should exist.

Absolutely right. The culture of helping out, code sharing and support cottage industries are making the Arduino a winner.

It's predecessor, the Teensy, has been discussed before; http://news.ycombinator.com/item?id=457740 But this is the Teensy++, despite having the same URL, hence me fudging the lameness filter. You get quite a bit more for a small price increase so it's well worth another look.

Got the first one. Really fun to play with. (Using it to build robots that drive around and communicate over an accoustic network)

I'd love to hear more about your acoustic networking if you've got time to tell.

Basically, I didn't want to spend money on wireless network chips and figured I could use the speaker+mic I was using for distance measurements for sending small bits of data too. It currently uses TDMA with 1 second time slots subdivided into 8 bits with sound being 1, and silence 0. The stunning 1 byte/s is good enough for me at this point. Embarassingly, they're still wired together to synchronize time. I'm mostly working on processing the sound to reduce interference (especially the motor noise). They can make a pretty reasonable guess at frequency, but it is getting hard to fit in the Teensy's memory. Maybe I'll get the new one.

As cool as it is to be sending data over sound, its only $25 for some of the cheaper wireless modules over at sparkfun: http://www.sparkfun.com/commerce/categories.php?c=16 That would be impossibly more practical, and you wouldn't really have to have them wired together to sync them. You could have a master transmitter that sends out a sync bit that everyone syncs with (or something...).

That's pretty sweet.

For synchronization, you could use a pattern of start/stop bits as used by RS232. It would take a few bytes to get synchronized, but it would probably work.

Can someone give me a sense of some projects you can do with a Teensy? I've never played around with programming chips like this before but sounds pretty cool from the comments.

It's difficult to give a scope of the possibilities. An autonomous 'remote control' car has been mentioned above. Other types of robots. Musical instruments. Burglar alarms.

Take a look at the exhibition section of the arduino forum: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?board=projects Also the projects from the "Designing with Microcontrollers" class at Cornell University: http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects...

Just ordered mine, don't have any specific plans for it just yet, just tought it might come in handy during summer-boredom. And at that price, incl shipping (to Norway!), it really was a no-brainer;)

But I do have a question that I couldn't find an answer for on their page, can it run without being connected to a computer? Can i just mount it with a 5V battery and send it on my verry own Mars-mission?o0

Given that I just ordered it I havent googled it that much, but do anyone have any blogs/communities they can recommend for reading/getting help/getting ideas/brainstorming?

Answer is yes. I often run it on my phone charger which has a mini-usb plug. All it needs is 5V.

I totally just bought one for the autonomous "RC"-car (it won't be RC when i'm done) that I'm gonna build this summer. Its gonna have gps and every sensor I can think of. Thanks god its summer.

Anyone writing their software for these things in a language other than C? I have tried cross-compiling various Schemes to run on these, but am not having much luck. (Scheme implementations seem to do a lot of weird things...)

I have not tried ECL yet, though, which might be easier... and I like CL better than Scheme.

Oh man, PJRC is so awesome. My first microcontroller ever was a PJRC 8051 development board.

Is the USB stack developed or do you have to write it for your standalone config?

They provide a bunch of ready-made apps that make the thing act as a keyboard, mouse and some other devices. I haven't looked at it in detail, but I got the impression that they've taken care of the nitty gritty bits of USB and let you do the fun stuff.

There is also an extremely well developed open source stack: http://www.fourwalledcubicle.com/LUFA.php

Are those 9 PWM outputs or inputs? Probably outputs. I need 8 PWM inputs, with an accuracy of 1/5th of a degree.

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