Every year we have a summer BBQ at work. There is always lots of food, drinks and good fun. This year it was proposed to have an interdepartmental talent competition. (As it turns out engineering is the only department brave enough). So after much discussion we decided that we would perform several individual talents. My talent… musical pet bowls! The Sealed Pet Bowl is the first product I helped develop during my first year at SureFlap. I developed very sensitive proximity/motion sensors that surround the bowl, when it detects something near it opens up. Since I worked on the electronics and firmware I am very familiar with it’s operation and knew it would be quite a simple mod to turn the pet bowl into an effective theremin/laser harp type instrument.
To get notes from the pet bowl I took the PWM output normally used to drive the lid and ran it to a small guitar amp. The firmware knows which sensor is being triggered so it was a simple case of making the PWM frequency dependant on which sensor was triggered. Then doing this to 3 pet bowls. Job done, a pet bowl instrument.
Now it was just a case of learning how to play the thing. Time was as limited as my instrument so I managed Ode to Joy. Good performance. Everybody claps. Roll on snare drum. Curtains. You are now looking at the SureFlap’s got (no) talent winner 2016! Video of the performance.
The new boards arrived yesterday, so last night and this evening I populated a board and programmed it. Worked first time, sigh. The old board has been running continuously for over a month and hasn’t lost a minute. So looks like it’s time to finish up the firmware and make some clocks!
The clock has been running for a week now without fail* so about time to order the next, and hopefully last, rev of the board. This time in white with no silk. What difficulty there will be in soldering will be made up by the pure sexiness of the board…
*ok one fail. The smd inductor I was using was under rated and burnt out after 12 hours. Since then it’s been fine.
The hardware is there and the firmware a short way behind. If only I had more time! Anyway time to stop and let it run for a couple of days, let’s see what the time is on Sunday!
After my first coffee table I was commissioned to make a second, this time using significant dates. Birthdays and longitude and latitude numbers were incorporated into the underlying equations that generated the rippling function. The function was carved in three panels into a beach worktop. The table was finished with hairpin legs and a coating of Osmo polyx-oil.
I needed to make a data logger to measure the inductance of a coil over time. The coil is flexible and so will distort while in operation. I wanted to know how much this would change the inductance in order to account for it.
I found a nice IC from Texus Instruments, the LDC1000 inductance to digital converter. However it comes in an annoying SON-16 package, so time to whip out the fine tip soldering iron and practice my dead bug wiring. (For various reasons I thought logical at the time (though probably not) I opted not to use the handy eval board.)
So I superglued it onto an arduino protoshield, added a few caps and it was done. To measure the inductance the LDC1000 needs to be clocked, which is what the green board kapton taped to it is doing. This is a breakout I made for the Freescale/NXP KL03 cortex M0+, clocking the LDC1000 at 3MHz. You might ask why am I using the arduino for the logging and the KL03 to clock. Well. Whatever.
I plugged in an Adafruit datalogging shield and a few simple lines of code later I was logging inductance data. Sweet.