Category: Making

  • Revised Raspberry Pi TrueCrypt Benchmark

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    Revised March 31, 2013 with updated benchmarking approach that uses actual access to the mounted volume. New results show no appreciable sensitivity to hash, which is as expected. The numbers are for encryption only (write). I have not pursued read. Hash Algorithm Encryption Algorithm Rate (MB/s) SHA-512 Twofish 2.8 Whirlpool Twofish 2.8 RIPEMD-160 Twofish 2.8…

  • Raspberry Pi TrueCrypt Benchmark

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    Note: The results in this post have been improved with more accurate values at Revised Raspberry Pi TrueCrypt Benchmark. I recently acquired a Raspberry Pi model B 512 MB from the excellent people at Adafruit. I am interested in it as a small computer for basic text processing, and am curious about its performance in…

  • Refigured Data Logger

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    The RIMU data logger I built last year received a major upgrade. I added a sound pressure level meter to learn how noisy it is and updated the case to make the switches easy to find, label, and operate. It took a long time to get it working, mainly because I forgot that using the…

  • Smoking Good Ribs—Temperature Management

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    I have smoked ribs about four times in the last couple years. I’ve been fortunate enough to have my father’s MasterBuilt smoker. It is a box about the size of a dorm fridge, and can readily smoke two racks, each cut in half. It has electronic temperature management and is well insulated. I’m fond of…

  • RIMU Calibration

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    I turned the freezer up to 7. I’m sure yours goes to 11, but I am not so lucky. After being turned up to 7, the resulting mean temperature is still too high at 18.8°F. And with that, we bid adieu to our refrigerator. It is around 20 years old—no way to be sure, and…

  • Freezer Swan Song

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    The last few weeks our ice cream sandwiches have been awful. I’m throwing away ice cream sandwiches, and I’m only marginally pickier than my dog. They’ve been gummy, almost squishy. We have been suspicious of the refrigerator since we smelled a hot electric odor—like burning dust. I monitored the fridge with the RIMU, and it…

  • Heat Less with Better Blinds?

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    Evidence is mounting that closing the blinds can reduce the rate of heat decline—at least when the wind is mostly still. The figure compares the heat loss rate to the indoor-outdoor contrast. Higher rates are bad. Closing the blinds keeps reduces the temperature loss rate by about 0.1 degree F/hour. Integrate that loss rate over…

  • Estimating the Home’s Heat Loss Rate

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    I’ve been collecting various sets of data with my Arduino-based RIMU.1 environmental data logger. In particular, I have seven nights worth of overnight records showing both indoor and outdoor temperatures. The data were all taken with the recorder in the same locations. Some nights are contiguous, but the 7-night set spans about 10 days. The…

  • Hot and Cold, Thermal Monitoring

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    Since the RIMU’s creation I’ve logged two noteworthy data sets along with several that are not yet ripe for sharing. I logged the refrigerator’s internal temperature overnight (using the thermistor) and I logged the oven’s internal temperature for a few minutes while making bread sticks today. The results are more interesting than I might have…

  • RIMU: Recording Independent Measurement Unit, an Arduino Project

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    I don’t remember where I first heard of the Arduino programmable microcontroller platform. An Arduino Uno, the variant I have, is about the size of a box of Altoids mints. It has a port to receive DC power, a USB port for programming and debugging, and a very capable microcontroller. It is programmed in a…