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31  Development / Other Software Development / Re: Class for both DHT11 and DHT 22 (temperature & humidity) on: October 09, 2012, 08:45:47 am
One suggestion for the code is to replace or augment the read11 and read22 routines by one unique read routine that would detect which one it is and return 11 or 22 in chk.

I'm not sure it is _so_ easy, but for example, having both [2] and [4] zero with a DHT22 should almost never happen, right ?

They are the lsB if I get it right, so humidity has to be 25.6, 51.2 or 76.8 for byte[4] to be zero.
Then in that case temperature has to be precisely 25.6 etc.
Pretty unusual.

To be even more confident, there could be a "confidence" variable based on previous measurements:
increase/decrease  a uint8_t counter for every non/zero value with saturation @ +127/-128, so DHT11 goes from zero @reset to -128 and DHT22 to +127.

Another thing is to replace the double by an int in tenths of degrees. So for DHT11 it would return array[0]*10;
32  Using Arduino / Project Guidance / Re: Anybody?! Started with Contiki or other 6lowpan on: October 07, 2012, 05:10:29 pm
Apparently no one is interested... No surprise, IPv6 is just not critical in home projects.

I'd guess that less than 1% of Arduinos have Ethernet or any conection to Internet. So why would you go for IPv6 at all ? Lots of efforts, and benefit zero
33  Using Arduino / Project Guidance / Re: W5100 vs ENC28J60 on: October 05, 2012, 04:48:03 am
Wow, zero download on my file ! Impressive how people are uninterested in ENC28J60 cheap Ethernet for Arduino !!!
34  Using Arduino / Networking, Protocols, and Devices / Re: Arduino Fio as SPI slave with ANT+ nRF24AP2 on: September 28, 2012, 09:45:42 am
I also abandoned SPI ideas early, especially since on my board is was already used at both sides (one Ethernet and one RF). Since the D0-D1 Serial is used for monitoring, you may want to use SoftwareSerial, apparently in 1.0 it have become better and standard library. I plan to do that, but didn't yet start that part of my project, so feedback is welcome.
35  Using Arduino / Networking, Protocols, and Devices / Re: Ethernet Shield ENC28J60 with Uno Rev3 on: September 28, 2012, 09:38:08 am
Support and development for the "old" Ethernet libraries for ENC28J60 were stopped more than one year ago. The best library (1.0 compatible) to use now is EtherCard from jcw (on Github).
36  International / Français / Re: Client TCP et ENC28J60 on: September 26, 2012, 06:21:36 am
Pas de progrès en vue pour la documentation d'Ethercard ?
37  Using Arduino / Project Guidance / Re: Arduino on an AVR Net Io with ENC28J60->Parsing GET Requests on: September 24, 2012, 10:33:39 pm
Hi Floo,

Your English is not so bad, don't worry about it, it's much better than to use another language and exclude the majority of the community (IMHO)

I didn't take much time to look at your example, but did you post your code or jcw's example here ?

Because I see the usual   ether.packetLoop() but nothing like any parsing of the response !
38  Using Arduino / Networking, Protocols, and Devices / Re: Ethercard library documentation... how to open, write, read and close a TCP SKT? on: September 24, 2012, 10:12:18 pm
In the Github repository, there is a specific (small) discussion about that.

Previously, the TCP client connections were always closed after the first packet was received from the server. If I understand correctly, multiple packet connections are not "supported" (but possible)

Line 623 in tcpip.cpp closes the connection by setting "tcp_client_statete = 4" (I believe the double "te" is a typo).

It was commented out recently in order to allow multiple packets to be received. But I have no exact idea of how you should evolve the tcp_client_state from 3 to 4 to 5.
39  Using Arduino / Project Guidance / Re: Multi-tasking: sending email, counting pulses, record/storing data on: September 19, 2012, 05:35:21 am
You shouldn't need to use two arduinos for that, since it supports interrupts.
40  Using Arduino / Project Guidance / Re: W5100 vs ENC28J60 on: September 19, 2012, 05:11:28 am

Unfortunately your links only include very few information. For example, there is no clear diagram with connector pinouts.
The 5100 board includes a 5V-3V3 regulator, but can it be used with a 3V3 supply as well ?
Nice to see you added a "useful links" page, but maybe you should populate it with something (like a link back to here ;-)

Could you also make a check on the consumption of the boards as said in the 28J60 review ?  Regarding this review, I'm surprised that michael had DHCP issues, for me (using a DINo) it worked at the first try.

@All, I relaised that this post does not get high on search because some keywords aren't present by accident. For example Ethernet Ethernet Ethernet !

I would also like to add some nuances to the other posts in this thread. While the 28J60 indeed does require a bigger load on the CPU (no TCP in HW for example), this could also have advantages : for example, it is possible to support 6lowPAN in the future  smiley-kitty

Also, DHCP is supported standard in EtherCard library, it's just a matter of choosing  static or not.
41  Development / Other Software Development / Re: What's the point of Firmata? on: September 17, 2012, 02:38:01 am
Firmata is part of the standard libraries. It is not loaded to the arduinos, but available in the IDE without extra download.

The idea is to use a MIDI-like protocol to remotely control an Arduino. The program on the PC sends something like "NOTE 3 ON", and the
output D3 goes ON. Other controllers allow to use PWM and ADC as well.

Not many people are using it, and prefer to put the intelligence in the Arduino instead of making PC programs.
It's just there (like SD, Ethernet or LiquidCrystal) if you want to use it.
42  Using Arduino / Project Guidance / Re: How to transmit data underwater? on: September 17, 2012, 02:11:52 am
I second dc42, this is "not for novice". To send data to your stuff underwater, you need as much power as you can (real RMS watts), the transducer you show could be used. Or a big woofer inside a big floating box. Rotation etc. won't help, in water it's omnidirectional. Think of submarines' sonars.

No FM between kHz here though, we are in the sonic frequencies ! This means switching the frequency between 500Hz-2kHz-maybe 40kHz. You could use the Arduino PWM for generating that. But already there, the attenuation of water will differ, hence the reach.

And then at the other side, you need to recognise the sound /demodulate. Relatively simple electronics ... for who knows it.
Look at AFSK on Wikipedia for example.

So, maybe the easiest way to do that is to use ... DTMF. Then you can send 4 bits (a nibble or half-byte) at the same time (0-F) using one of the sounds, and
there are DTMF decoder chips that will do the decoding for you.

See for example for a decoder with schematics.

Of course, this is only for one direction ! For bidirectional, you have to duplicate all circuits and go half-duplex.
43  Using Arduino / Project Guidance / Re: Gunshot Detector on: September 17, 2012, 01:46:41 am
Gunshots have no specific frequency, it is "noise", i.e. many different unrelated (not harmonic) frequencies. So FFT etc. is likely to be difficult.

Detecting a gunshot with a microphone will be easy (threshold)
You _could_ try recognising different types of shots by "correlating" some series of ADC captures, assuming that the distance
mike-gun won't screw everything by saturating the microphone...

In any case, an Arduino can't usually run at speeds high enough for simple audio processing. For example, it can't even play MP3.
Go for a fast 32-bit at least (PIC or ARM)
44  Using Arduino / Project Guidance / Re: Reading FM on: September 17, 2012, 01:38:40 am
Well this AGW packet engine incorporates some audio to data decoder. So basically you either need to reverse engineer that and code it again, or interface with it if it has an API.

It's a bit surprising that there is some audio in the chain though. You use the audio input of the PC ?

I'd rather consider to leave that audio decoding system alone and replace the receiver by a better documented 433 receiver to either an arduino or USB, if you know the format/protocol of teh messages. If not, replace the sender as well by another 433 sending device (paired with the receiver).
45  Using Arduino / Project Guidance / Re: Wirelessly transmitting images from camera through wifi to computer on: September 17, 2012, 01:30:53 am
The big issue with this kind of setting is that arduino etc are poor little 8-bit chip, which means your solution is feasible but would be terribly slow.

Since you talk about high quality photographs, I presume you have Megabytes for each picture. Disregarding the need for some error correction mechanism on serial, you'd need 4 hours to transmit a 200MB file over a 115k serial line...

A wild idea from my side is to contact the people at and ask them if they could do what you want. Not sure if it is feasible, but that would be a smarter 32-bit chip in an SD form factor fitting directly inside your camera, and sending bluetooth. No ugly wires, power supplies etc. The imp is still in preprod AFAIK, but should be the best solution.
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