Month: November 2014

Emulating An Arduino Sketch in a Spreadsheet

Many times I’ll mock up my Arduino formulas in a spreadsheet before I start building a sketch. One of the more complicated Arduino commands to emulate is the MAP command. The Arduino code: height = map(adc, 171, 512, 12, 0); In Excel becomes: = (adc-in_min)*(out_max-out_min) / (in_max-in_min) + out_min The following emulates a voltage divider …

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Installing & Programming the VV-898 2m / 70cm Ham Radio

Ricky and I installed my new Leixen VV-898 2m/70cm 10 watt dual band Ham Radio in my truck today. It’s $135 delivered, from http://www.radioddity.com. Ricky pulled out the ashtray and installed the radio in the exposed cavity. I then wired the power to the power leads from the old cigarette lighter (radio is about 10 …

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The MQTT Connection

MQTT stands for MQ Telemetry Transport. It is a publish/subscribe, extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks. The design principles are to minimise network bandwidth and device resource requirements whilst also attempting to ensure reliability and some degree of assurance of delivery. These principles also turn …

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