## Modeling auto ranging resistance meter using Arduino

Resistors are most common components in electronics. They are used to limit current flow, pull-up or pull-down voltage, scale down voltage and so on. If you are electronics enthusiast probably you have full bin of them. But when you are trying to pick one from a pile things start to be annoying. We know how those promises “I will keep them organized!” work. A plan B is to have handy robust tool to measure resistor value on the fly. Before soldering any resistor it is always a good practice to check if value is correct. Praveen have shared his thoughts on how simple ohmmeter can be build by using Arduino and small amount of passive components. His meter measures voltage drop across unknown resistor and thus calculates resistance vale by applying Ohms law. He also implemented auto ranging feature to have best accuracy equally by measuring small or high value resistors. The trick here is by measuring voltage drop. If voltage drop gets too small, then ADC looses sensitivity. So Arduino simply selects different known resistor make voltage drop higher.… Continue reading

## High Accuracy Digital LC Meter

You’re get involved with many projects that require to measure the impedance of a component? You couldn’t find the right tool to help you overcome the hassle? Well, in this case, you might want to create a brand new high accuracy digital LC meter. Digital LC meter, or it also known as the “LCR” meter, is the electronic test equipment, which normally being used to measure the impedance, such as inductance, capacitance and resistance! The digital LC meter started to gain its popularity over the analog type, due to their high accuracy and high input impedance. Some other features like auto zeroing, auto ranging, auto power off and down mode are making the digital LC meter more powerful than the analog LC meter! This project is based on the PIC16F628 and PIC16F84 base inductance/capacitance, where the measuring range is from 0 to >0.1 uF for capacitance and 0 to >10mH for inductance. The expected accuracy is in between +/- 1% of reading +/- 0.1pF or +/- 10nH. An LM311 comparator with positive feedback is being used to make a parallel… Continue reading