Sunday, April 13, 2008

PID Tuning Application for Arduino Silvia Mod

As part of my Silvia modifications, I also wrote a special application to help in tuning the PID. Here is a screenshot of the application with an image of a shot and recovery. This is measure the temperature at the top of the boiler.

The application is written with Processing. It can run on any platform, and it's easy to communicate with the Arduino over the usb-serial interface. The "Bare Bones" code for the Arduino is here and that page has a link to the code for the Processing Ap.

Wednesday, April 02, 2008

Arduino and Silvia: Two Italians, One Tangled Affair

Arduino knew the two of them could make sweet coffee drinks together!

In this precisely hot affair, the Italian born microcontroller board, Arduino, has won the heart of a sensuous piece of Italian engineering named Silvia, an espresso machine by Rancilio. Silvia, after an earlier stint with a microcontroller named PIC (those Harvard Architectures are all such squares), felt she could do better.  She was looking elsewhere for someone to add brains to her great body. Arduino was a great match. He is easy to talk to, isn't too fancy or expensive, but has the hardware she requires. For his part, Arduino respects Silvia for her sturdy simplicity. She opens up easily, and isn't difficult to get intimate with. Simplicity comes naturally when you are a water heater, pump, and solenoid. Sure, she's got some switches too, but Arduino knew the two of them could make sweet coffee drinks together! 

In courtship, Arduino gave many gifts to Silvia. One of the first was a fine real time clock featuring calendar, sleep timer, and wake-up alarm! He also decorated her boiler with a thermometer he vigilantly monitors to help regulate her temperature.  When she makes espresso, it's most delicious when her temperature is precise and steady. He also keeps a stop watch so he can time her pushing as she pumps water through the cake of ground coffee. "Egads," he says, "It is simply not espresso if she take not between 25 and 35 seconds!" Arduino holds all of Silvia's switches, even her main power switch.  Anyone who wants to talk to Silvia talks to Arduino first. Certainly, it's old fashioned, but it makes Silvia feel safe. With his fine manners and protocol, she prefers that he, not any old stranger with a finger, pass her messages.

Arduino doesn't just manage Silvia's connection to switching fingers. With the end of a wire dipped into her reservoir, Arduino can raise an alarm if she is about to come to a gurgling halt in her endless thirst for water. Perhaps the greatest extravagance Arduino allows is a connection to a nunchuck controller. He relays messages to Silvia from the nunchuck, and she adores it as it makes her feel like the wildly entertaining Wii. No doubt, given all the connections that entwine them, this relationship will continue a good long time to come. Together the two lovers will enjoy many magical mornings making delicious espresso.

Want a closer look under the hood? Ready to build? Check out the CoffeeTronics section on the Arduino wiki.