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Topic: Teensy 3.0 (Read 39791 times) previous topic - next topic

el_supremo

The Teensy 3.0 I ordered is on its way. In the meantime I have some questions.

- is there a forum for the Teensy 3.0 or is this thread the best place to ask questions?
- I notice in the Beta5 IDE Tools menu that you can choose one of three CPU speeds - e.g. to overclock at 96MHz. Is this selection all you need to do or do you also have to make some sort of hardware change?
- I'd like to play around with the ARM's DSP instructions. Is there any support to allow use of them in a sketch or do I have to get my hands dirty with assembler?

Thanks
Pete

westfw

Quote
there is a huge difference in performance between SD cards


Have you seen the conversation about many formatting utilities not formatting SD cards "correctly" ?

http://www.adafruit.com/forums/viewtopic.php?f=31&t=20861&start=0

John Beale

Quote
Sadly, the Raspberry Pi has a bootloader bug that makes it incompatible with some cards.


Somewhat off topic, but just FWIW, the R-Pi has been reported to show about 20 MB/sec both reading and writing to a "SanDisk Extreme SDHC  4GB class 10" according to http://elinux.org/RPi_Performance#SD_card  
Somewhere around June/July 2012 there were some bug-fixes to the SD card I/O routine firmware in the R-Pi, which improved compatibility with several different types of cards.  Most cards perform slower than the above example.

John Beale


- I notice in the Beta5 IDE Tools menu that you can choose one of three CPU speeds - e.g. to overclock at 96MHz. Is this selection all you need to do or do you also have to make some sort of hardware change?


My experiments indicate that the menu selection alone does in fact change the clock speed, nothing else required. See for example http://dangerousprototypes.com/forum/viewtopic.php?f=2&t=4606#p45080

el_supremo

Thanks very much John.

Pete

fat16lib

#110
Oct 23, 2012, 04:56 am Last Edit: Oct 23, 2012, 05:03 am by fat16lib Reason: 1
The main difference is that industrial cards use SLC flash and consumer cards use MLC flash.

SLC flash tends to perform better in embedded applications.  For example wear leveling remaps occurs more frequently for MLC flash since each cell has a lower maximum number of write cycles.

A comment on bus speed. 

The Teensy uses 1-bit wide SPI at 24 MHz.

Common Version 2.0 SD and SDHC cards support the 4-bit SD bus at 50 MHz.  This is about eight times the bandwidth that Teensy has.

fat16lib  , integration of the chibios to the teensy sounds very interesting. Thanks for the work.

How compatible do you think it will be with other arduino libraries ? And what's the estimated latency, generally speaking ?

fat16lib  , another  question:

How compatible is the chibios library to standard arduinos(atmega 328/1280/2560) ?  and what's the latency ?

Nantonos



It's in stock in the Netherlands now.

http://www.pieterfloris.nl/shop/category.php?id_category=45


Ordered.


It arrived this afternoon, along with a Teensy 2.0 which I briefly tried and will use as a USB MIDI output for my controller project. Have not yet tried the 3.0, about to do that now.

MauJabur

#114
Oct 25, 2012, 04:43 pm Last Edit: Oct 25, 2012, 05:11 pm by MauJabur Reason: 1
Hi!

I successfully connected teensy 3.0 to the WIZ812 Adaptor Kit (edit: via breadboard, of course) and WIZ812 Ethernet Module!



I can use DHCP and ran several of the server examples.

There's a problem for now, and I'm still looking into it, but if somebody else has something to add, it would be good!

The problem is that it can't connect to websites, as in DnsWebClient. I don't know yet if it's not resolving the DNS or if it's another issue...

here's my results:

localIP: 192.168.1.113
subnetMask: 255.255.255.0
gatewayIP: 192.168.1.1
dnsServerIP: 200.162.196.29
connecting...

UPDATE: It's not resolving DNS names, I used IPAddress serverName2(74,125, 234, 243) for google and it went through! I'll check my DNS server now...

UPDATE 2: It was my DNS server (but it works on my win7 machine...) Now I'm using openDNS and it works...

localIP: 192.168.1.113
subnetMask: 255.255.255.0
gatewayIP: 192.168.1.1
dnsServerIP: 208.67.222.222
connecting...
connected
HTTP/1.0 200 OK

cyclegadget


I have this SD card breakout board in the color red. https://www.sparkfun.com/products/544

I want to hook it to the Teensy 3.0, I think I can hook it directly to the SPI pins without any added resistors or such. Can anyone tell me if that is correct or if I need additional parts?


Thanks,
Mark
Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

fat16lib

Yes you can connect it directly.

cyclegadget


Yes you can connect it directly.


Thanks, I will report hopefully tomorrow on my results!
Good links: Eagle tutorial= http://www.youtube.com/playlist?list=PLDE1858BD83D19C70
General Arduion tutorials = http://tronixstuff.wordpress.com
http://www.gammon.com.au/forum/bbshowpost.php?bbtopic_id=123

el_supremo

I tried a benchmark of my own using a function which computes the bearing between two locations specified as lat/long. It produces essentially the same kind of timing as seen before.
In summary, compared to a Duemilanove (=2009) the result of calling the function 10000 times is:
2009 @ 16MHz 12.57secs
T3    @ 48MHz   8.30 secs
T3    @ 96MHz   7.82 secs

The interesting thing I noted was the difference in the size of the code.
The Duemilanove code is 4764 bytes whereas the T3 code is 19984 bytes! I presume that the T3 is hauling in different libraries but it seems to be a bit excessive. OTOH it is 19984 bytes of a 131,072 byte maximum so there's plenty of room to spare :-)

Pete

Coding Badly

I tried a benchmark of my own using a function which computes the bearing between two locations specified as lat/long.


Using float or double?

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