Great code however am having strange outputįor the source value of 220 I have a known R2 of 10 Ohmīut the output from the following code is showing 5274. A list of fixes and additions to the Visual Micro Arduino IDE plugin for Visual. If it’s your connections… well, that should have been the first thing you checked! Reply If that doesn’t fix it, then either your entire Arduino is screwed up, or it’s your connections. If it’s your analog pin, simply moving the wire from analog pin 0 to analog pin 1, and modifying line 1 of the sketch to match your new analog pin should fix the problem. If this doesn’t work properly, then your analog pin 0 is messed up. If this works properly, it’s probably a bad resistor that you’re trying to check, or a very big resistor, in which case you need to have a bigger R1 to get reliable values. This should give you a Vout of 5V (since none of the voltage is sunk to ground), and an R2 of 0 (which is actually infinity). You could test to see if it’s a problem with analog pin 0 by removing R2 from the circuit. Since electricity follows the path of least resistance, the point directly before R1 is Vin (5V on this setup), after R2 is 0V (connected to ground), and between R1 and R2 is Vout (the amount not being sunk to ground by R2). A voltage divider works by sinking a portion of the voltage in the circuit back to ground. If it still doesn’t work after that, I would conclude that you have a bad resistor or your analog pin 0 has somehow been damaged (the latter is really unlikely). If size is left unwired, a size of 4096 bytes is used. You should set the buffer size to a value larger than the number of bytes you expect to read or write. These are the readings I got with a 200 Ohm “unknown” resistor:įirst, check all your connections, and also verify that you have updated the sketch with the new resistance value for R1. The mask input designates whether to set the I/O receive buffer, I/O transmit buffer, or both. After you’ve got the LCD set up, connect the Ohm meter as shown above, and upload this program to the Arduino: #include
That will show you how to connect everything. First you’ll want to read our tutorial on setting up an LCD display on the Arduino.
One reader commented that they would like to display the resistance measurements on an LCD. Vout: is the voltage drop across your unknown resistor.