<p>Yah, I want to help out with this. </p>
<p>So ill check it out tonight and see what can be whipped up this week.</p>
<p>-rma</p>
<p><blockquote type="cite">On Mar 12, 2011 10:31 PM, "Josh Myer" <<a href="mailto:josh@joshisanerd.com">josh@joshisanerd.com</a>> wrote:<br><br>I prepared an LM335A (analog temperature sensor) for use in the laser's water bucket: it's soldered down to leads, then encased in a chunk of sugru. The slew is going to be a bit much (it'll probably be at least 15 seconds behind real time, but that's a guess. I have no idea what the thermal mass of sugru is, and can't be arsed to run a proper test.)<div>
<br></div><div>Basically, it just updates the LCD with "LASER BATH TEMP\n31.4", no fancy degrees C or anything.<br clear="all"><br><div>I also have a 16x2 display and am willing to donate a Volksduino (and the handful of other components), if someone else wants to do the actual circuit board bits. I actually got the code working with a circuit on a solderless breadboard (it's dead simple), displaying the temperature in my garage.</div>
<div><br></div><div>We'll need a wall wart (oh, hey, Noisebridge has fucktonnes!), and an enclosure. I'm not sure how we'll manage to fabricate a custom enclosure for an Arduino project, but I suspect someone will have ideas.</div>
<div><br></div><div>Is anybody available to do the tiny bit of design and soldering required to do this properly? I've got too much on my plate right now to spend the ~4 hours required to get everything soldered nicely, tension relief right, and make sure that we can use the Volksduino for more than just temperature sensing. I'd like to tack on a "room temperature" sensor and find a way to sense when the laser is on. Dumping all this via serial to something that feeds a webserver would be hi-larious. Cacti/munin/${UGLY_RRD_TOOL} graphs of all the laser state! Woo!</div>
<div><br></div><div>Temp sensor datasheet: <a href="http://www.national.com/mpf/LM/LM335A.html#Overview" target="_blank">http://www.national.com/mpf/LM/LM335A.html#Overview</a></div><div>LCD instructions: <a href="http://www.ladyada.net/learn/lcd/charlcd.html" target="_blank">http://www.ladyada.net/learn/lcd/charlcd.html</a></div>
<div><br></div><div>Schematic: do the LCD thing. </div><div><br></div><div>Temperature probe schematic:</div><div><font face="'courier new', monospace"> +5V ----[1k resistor]-----o---------(Probe red lead)</font></div>
<div><font face="'courier new', monospace"> | (Probe black lead)----GND</font></div><div><font face="'courier new', monospace"> (Analog0)</font></div>
<div><br></div><div>That lead probably wants a filter cap and a ferrite bead, but it's good enough for government work (Bacchus flies with more or less exactly this).</div><div><br></div><div>Code: read analog0, then, in floating point (yes, float):</div>
<div><br></div><div><font face="'courier new', monospace">float sensor_calibration = 0.00; // an offset, each sensor is a very slightly beautiful and unique snowflake.</font></div><div><font face="'courier new', monospace">int adcval = analogRead(0);</font></div>
<div><font face="'courier new', monospace">float degC = adcval*5.0/1024*100 - 273.15 - sensor_calibration;</font></div><div><font face="'courier new', monospace"><br>
</font></div><div><font face="'courier new', monospace">// Tack this into the LiquidCrystal hello_world example, replacing the millis() print with degC.</font></div><div><font face="'courier new', monospace"><br>
</font></div><div>Any takers?</div><div>-- </div><div>Josh Myer <a href="tel:415.230.9791" target="_blank">415.230.9791</a> <-- NOTE: New number!<br>
<a href="mailto:josh@joshisanerd.com" target="_blank">josh@joshisanerd.com</a><br>
</div></div>
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<br></blockquote></p>