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1  Using Arduino / Sensors / Reading sensors and acting on their input on: July 12, 2012, 08:30:36 am
I am building a greenhouse that is going to be totally controlled by my arduino mega. At the moment I have two DHT11 sensors a light sensor  and two voltage sensors. One for battery ad one for solar. Then I have servos to open vents and intake and extralegal fans controlled by relays. All this data is displayed on an LCD aswell as sent via xbee to a second arduino that is displaying the info.

On to the problem. I would like the arduino to always be updatin the LCD with the most uptodate info. But. If it gets into a a 5 min delay that allows the battery to recoup the display dose not update. How can I create a separate loop that is always running?
2  Using Arduino / Networking, Protocols, and Devices / Your Arduino becomes a OpenDmx USB interface on: February 26, 2012, 05:04:20 pm
Below I have added the OpenDMX page from the Arduino Playground. My question is to make this wireless using two arduinos....How can I do this?

Your Arduino becomes a OpenDmx USB interface

All this just works with an old arduino board, since the UNO there is a different chip used smiley-sad

This short tutorial explains how to use the Arduino as a USB to DMX interface for software that works with OpenDmx. This USB to DMX interface enabled you to use your PC as a DMX master device to control DMX slave devices.
DMX (Digital MultipleXed) is an agreement over the connection between lighting controllers, dimmers, scrollers, scanners, etc. With DMX you can control 512 channels.
OpenDmx is a Open Source project to produce a low cost USB to DMX interface with a GPL license.

The OpenDmx USB circuit simply consists of a USB to serial converter (FT232BM) and a driver block (max485). This circuit takes care of transforming your signal from USB to Serial and from Serial (RS 232) to DMX (RS485) but it does not care about what are you sending (transmitting). The signal itself has to be produced by your PC. The PC has to take care of timing and order of the signal. This kind of devices is called "unbuffered", because the USB to DMX device is not storing or buffing anything, if your computer hang-up, your signal gets also jam.
FT232BM chip is a USB to Serial converter produced by FTDI.
The Driver Block (max485 or SN75176) Outputs the 3 Pins are needed for sending DMX (DMX-Pin1 � Reference (GND); DMX-Pin2 � Signal inversion (cold); DMX-Pin3 � Signal (hot)). Furthermore is the Driver Block taking care of changing the Arduino signal Voltage (0V / 5V, according to RS232) into the DMX signal Voltage (-2,5V / +2,5V, according to RS485).

The Arduino is using the same USB to Serial converter like the OpenDmx USB device. The only thing we have to add is the driver block (max485). We just have to wire up a driver block (as you can see in the following schematic) and connect the Driver Block Input (DI) to the RX Input (output of the USB chip) at the Arduino. That's it. Just install the driver for the OpenDmx USB interface, for example from enttec ( ) and get some software or write your own programm.

Here are some links where you can find some software and building examples: (Windows and Mac opensource)
a good one for linux
(edited by tomek ness (k3/fhp))
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