Kelly Robotics » Arduino

RobotC / Arduino Controller

kellyds — Sun, 13 May 2012 14:30:40 +0000

The latest controller to fall under to control of RobotC is the Arduino! While programming the Arduino w/ it’s existing development environment is not really all that complex, RobotC does bring some significant capabilities and advantages to the table.

Interactive debugging
Easy access to a host of sensors
Easy learning curve lowered for those FIRST Robotics fans (FIRST Tech Challenge specficially)
Possibly be able to simulate multi-tasking (fast task switching)

If you are interested in finding out more about this head over to robotc.net to download the demo and start playing with it today!

Arduino Temp Monitor Progress

kellyds — Sun, 13 May 2012 03:12:47 +0000

I’ve finally made some time to work on the temperature monitor for the server room.

The Temperature Monitor currently consists of an Arduino Uno R3, Ethernet Shield and a small prototyping board.

It will currently listen to port 80 on an internal IP address. When a request comes in it will create a simple web page that shows the raw value from the sensor, degrees Kelvin, degrees Celsius and degrees Fahrenheit. In addition to the web page there is an RGB LED that reflects the current temperature. The picture below shows the simple web page and the color scale for the RGB LED.

The prototype board consists of the two sections:

Temperature Monitor:
LM335A temperature sensor, 2K ohm resistor and a 10k ohm potentiometer.

The LM335 has a positive terminal, negative (signal) terminal and an adjustment terminal. The 10k pot attaches to the adjustment terminal to help calibrate the LM335A.

RGB LED:
3 x 220 ohm resistors and an RGB LED.

The RGB LED is driven by three PWM outputs from the Arduino which controls the effective voltage sent to each of the Red, Green and Blue terminals on the LED.

The LED will be solid blue when the temperature is 65 degrees or colder, solid green at 73 degrees, solid yellow at 81 degrees and solid red at 89 degrees or greater. This provides an at-a-glance status of the temperature in the server room.

After I get the Arduino sketch cleaned up a little I’ll post the first draft of the program.

Planned improvements:
– Better looking web page. Pulled from an SD card on the Ethernet Shield. Will use character replacement to ‘inject’ the variables into the web page.

– The formula for calculating the temperature is dependent on the current voltage entering the system. Would like to be able to measure the operating voltage and feed that value back into the formula for calculating the temperature.

– Add averaging into the ‘current’ temperature to filter stabilize the LED and values on the web page

First Arduino Project

kellyds — Tue, 17 Apr 2012 02:25:47 +0000

I’ve finally come up with a reason to play with the Arduino. Last week our server room’s AC went offline and the building’s AC is turned off. When the our sys admins got there in the morning it was a scorching 118 degrees in the server room. While we could probably buy a sensor or use one of the computers in the server room to send notifications about temperature problems that wouldn’t be nearly as interesting.

So, I’m going to build an Arduino system that will monitor the temperature in the room and send an email whenever it rises past a specified threshold. Additionally, it will have a small web server that we can use to see what the current temperature is in the room.

Equipment:

Arduino Uno R3
Ethernet Shield w/ SD Card Slot
Temperature sensor

Software:

Simple Web Server (1 page stored on the SD card)
Simple email sender (template stored on the SD card)
Read the thresholds from a file on the SD card
Monitor the temperature for exceeding the threshold
Datalog the temperature (rotate logs once per month or as size dictates)

I’ll keep posting updates here as I work through the project…