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1  Using Arduino / Sensors / Re: Dodgy LM35 Sensor? on: September 03, 2014, 02:37:31 pm
the Arduino calculation if ok for that voltage, the lm35 must be bad, don't you have another one to test ?
2  Using Arduino / Project Guidance / Re: Arduino IDE to Atmel Studio - Possible???? on: August 27, 2014, 05:44:14 pm
did you try visual micro ? I think it works with atmel studio. You can compile arduino projects without any modification.
3  Using Arduino / Sensors / Re: dht11 values returning on: August 24, 2014, 09:57:48 am
actually, dht11 can be read every 1s (http://www.micro4you.com/files/sensor/DHT11.pdf),
2s is for dht22, but that is definitely what causes bad readings.
4  Topics / Home Automation and Networked Objects / Re: detecting new device on the network with an ethernet shield on: July 23, 2014, 02:50:45 am
hello,
issue 1 : do you really need tcp ? maybe you could just use UDP unlike xPL xAP protocols.
issue 2 : you need a mac address, to run Ethernet shield, why not use it.
issue 3 :
 - have it in code
 - spi eeprom
 - if you don't need to keep it against reboots you might generate it randomly.
5  Using Arduino / Networking, Protocols, and Devices / Re: NRF24L01 2.4Ghz 3.3v on 5V? on: May 13, 2014, 05:53:56 pm
In table 1 of the datasheet it is clearly stated VDD Power +1.9V - +3.6
Only input voltage is 5V tolerance, and in this case you're even limited to 3.3V max for VDD.
It might work with 5v VDD, but the device could fry early.

Some devices implementation include a 3.3v regulator, if you really need to plug it on 5v
6  Using Arduino / Networking, Protocols, and Devices / Re: nrf24L01+ strange behaviour on: April 09, 2014, 12:19:18 pm
please note that the problem is with gcopeland fork, original manicbug version had 500ms which is far higher than the max message send duration (a bit less than 30ms on my calculations) .
Anyway the timeout is there only to deal with local communication problem with the device which should never append.
But in gcopeland version timeout is too  small and reduce actual retries count.
7  Using Arduino / Networking, Protocols, and Devices / Re: DMX-512 over 433MHz WIRELESS cheap radio on: April 09, 2014, 10:35:37 am
I'm playing with nRF24L01+ now, it's said to be 2Mbps but that's air bit-rate without overheads, retries,... I actually achieve 140Kbps at 10m of usable payload..

Maybe by multiplexing 2 of 4 devices on different channels ?
It also exist amplified models that are said to have 1000m range, so it could do it at 100m.
8  Using Arduino / Networking, Protocols, and Devices / Re: nrf24L01+ strange behaviour on: April 09, 2014, 09:56:45 am
I got it working now, the cap is very useful to improve quality, but the problem had something good :
I think the rf24 library does not calculate timeout right, and then it cuts too early.
the formula used is :
(retransmit count +1) x Retransmit Delay

it does not take actual transmission time into account. I came with a formula that match pretty well :
Code:
(retransmit count +1) x ( Retransmit Delay +  (total message lenght + 10bits) / Datarate + 130us )
with total message length to be calculated from datasheet but max is 329 (58 bits + payload by default) if my calculation is good.
130us are for pll startup.
for the 10bits, I don't know but it work well at any rate.
9  Using Arduino / Networking, Protocols, and Devices / Re: Single Wire Interface Between Two Arduinos on: April 01, 2014, 03:24:36 am
I think there's not so much overhead in OneWire, (soft serial has its own costs) if there is only one slave, you don't even need to use addressing. About 14kbps can be achieve with very good reliability.
Maybe you could write your own protocol inspired by the time-slot mechanism used in 1-wire, i's quite simple.
10  Using Arduino / Networking, Protocols, and Devices / Re: MAC Address on: April 01, 2014, 01:28:45 am
mac is just an array of six bytes so :
byte mac[] = {  0x90, 0xA2, 0xDA, 0x0E, 0xFE, 0x16 }; but this is not mandatory, almost anything will work. This just has to have no duplicate on the local network, that's why you got an unique address on the package.

For the IP, this referer to a free address on your local network, (DHCP might not be an option, it's usually simpler to use a static IP for http servers.)
you will be able to see your web page at http://192.168.1.203 in you browser if you use the IP in the example you gave.
11  Using Arduino / Networking, Protocols, and Devices / Re: nrf24L01+ strange behaviour on: March 31, 2014, 05:39:18 pm
with the cap, the arduino nano fail to communicate with rf24.. thNO still work, I will try with a good 3.3 voltage.
12  Using Arduino / Networking, Protocols, and Devices / Re: MAC Address on: March 31, 2014, 05:34:19 pm
I use to do :
   for (byte i = 0; i < 6; i++){ mac = (i ) ? random(256) : ((random(256) & B11111110) | B00000010); }
may not be politically correct, but it works : the probability of duplicates is so small that it will never append.
after what, I store it in eeprom, to reuse the same after reboot.
the big advantage is you can use the same sketch with several devices without the need to take care of mac address.
13  Using Arduino / Networking, Protocols, and Devices / nrf24L01+ strange behaviour on: March 27, 2014, 12:08:12 pm
Hello,

I trying to use nrf24L01+ modules, I used maniacbug library.
At first, with default helloword I got many send errors, but packets got received many times. So I feel it's a problem with ack.
But the strange thing is, I tried to lower speed (250kbps) , and it got worse. so I tried 2Mbps and... it works with no errors at all !!!

I have an arduino nano and a duemilanove.

I tried lowering power, in case 3.3v on-board regulator is to weak. but did not change anything.

also tried coperland fork : https://github.com/gcopeland/RF24, that work a bit better at 1Mbps but still not well.

Anyone got that kind of problem ?
14  Development / Other Software Development / Re: Arduino Ethernet and ENC28J60 Module ? on: March 21, 2014, 09:23:27 am
I don't see why it would not work, what kind of error do you get ?
15  Development / Other Software Development / Re: Arduino Ethernet and ENC28J60 Module ? on: March 19, 2014, 03:28:37 am
that was in my first post, did you try it ?
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