cyborgworkshop.org

The pressure transducers are on order from freescale so, while I wait for them, I’m starting to look at moving to the next generation of WHIA.

What I’ve learned.

• I’m a sensor whore and will always want to tack on more sensors.
• The arduino is amazingly resilient, but the USB connectivity can be unstable over long periods of time.
• Manual HVAC dampers aren’t exactly what one would call high quality.
• Outdoor temperature sensing can be a PIA

With that in mind, first we need to layout the goals for v2

• 10 temperature probes (DS18S20P 1-wire)
• 10 Humidity probes (Unknown, but 1-wire)
• 15 window servos (to control the blinds)
• 10 vent servos (Damper control)
• 5 HVAC pressure sensors (Main vent and branches)
• 2 Anemometers (Main Vent and outdoor)
• 1 Rain gauge (outdoor)
• LCD control panel (Feedback)
• 1 blinkenlight for each sensors (Geek Candy)

Without the blinkenlights, we’re talking about between and 39 and 53 IO pins depending on how I use 1-wire.  I’m planning on driving the LEDs with a MAX7219 8×8 LED driver. I should be able  to access 64 lights using 3 pins on the uC, so that’s a good match and allow me to blink a light every time a sensor or driver is accessed.  The LCD panel will just be a simple old i2c planel giving some generic status messages and essentially eye candy.  Now, the big question.  Multiple Arduinos connected via i2c or that fancy new Arduino Mega?… If I use the Mega, I can just create a Shield again and that will make my PCB a little simpler but multiple arduinos talking i2c is just cool!  I am dumping the protoboard this time, it will be all bread board and then sent off to the PCB guys for some fiberglass and copper.

FYI, i’m not abandoning WHIA 1, it’s going to keep getting updates and features as my test bed system so I’ll have a full write up of the pressure sensor integration as soon as they show up.