Arduino Sensor Display Unit Overview
3,456 views · Published 2 August 2010 · 6:27 · Indexed 9 October 2026
Channel: aonomus · 2010 · Science & Technology
My arduino sensor display unit is a simple little project. Simple but born out of necessity. I wanted to monitor multiple voltages and high current levels beyond what a standard multimeter can handle, and to add a little more safety to the process. An Arduino reads voltage inputs from sensors and displays on an LCD screen, fairly simple. The voltage sensor is a basic voltage divider with a few range settings, accessible internally. I can have either 0-15V, 0-25V, or 0-50V ranges, though with the low display resolution, I opt for the widest range. The current sensor uses a 0.001 ohm current sense resistor with a MAX4372 current sense amplifier with a gain of 50V/V. That combination gives a working range of 0-28V common mode voltage and 0-100A . Update speed is fairly fast on all 4 sensors, the original problem in update speed was in the LCD4Bit Arduino library. The problem was that when using the LCD.cursorTo(x,y) uses a for() loop to iterate through each column to get the cursor to the position desired. In order to access the second row, the library iterates through 40 x row + column number of positions. That process eats up a large number of instructions. The workaround was simple, sprintf(string, v1, v2, a1, a2) with the appropriate spacing so that only one cursorTo(1,1) command is ever called per loop and uses minimal time to write to the screen.
