Daniel @ panstamp.com writes:
We know many of you were wondering when we’ll release a power meter compatible with panStamp. And here we are, sooner as expected, with a first prototype. We at panStamp are passionate about simplicity so you may guess that either electronics or firmware application have been designed to be as compact and efficient as possible.
panStamp Power meter board - [Link]
The MAX71020 is a single-chip, analog front-end to be used in high-performance revenue meters. It contains the compute engine found in Maxim’s fourth-generation meter SOC and an improved ADC, and interfaces to the host microcontroller of choice over a SPI interface.
MAX71020 Single-Chip Electricity Meter - [Link]
Raj from Embedded Lab describes in his latest tutorial the theory of a very basic digital capacitance meter and its implementation using a PIC microcontroller. It is based on the principle of charging a capacitor through a series resistor and determine the time required to charge it to a known voltage. The built-in analog comparator and Timer2 modules are used in this process. The meter can measure capacitance from 1nF to 99.99 uF.
Digital Capacitance Meter using a PIC Microcontroller – [Link]
MeterBasic is a fine program for the hobbyist who wants to generate a simple scale on occasion. MeterBasic is based on a subset of the features found in Meter. It requires no key and has no time or usage limitations. To provide an incentive to upgrade from MeterBasic to Meter, many of the features found in Meter are absent.
MeterBasic – Software for drawing analog panel meter scales - [Link]
This is 60 MHz frequency meter / counter for measuring frequency from 10 Hz to 60 MHz with 10 Hz resolution.It is a very useful bench test equipment for testing and finding out the frequency of various devices with unknown frequency such as oscillators, radio receivers, transmitters, function generators, crystals, etc. The meter provides very stable readings and has excellent input sensitivity thanks to on board amplifier and TTL converter, so it can even measure weak signals from crystal oscillators. With the addition of prescaller it is possible to measure the frequency of 1GHz and above.
60 Mhz Frequency Meter / counter - [Link]
This circuit is a digital sound level meter with a LCD screen, capable of displaying 80 characters (4 rows with 20 characters on each). You can build this LCD display. It also provides more debugging information, such as the minimum and maximum analog-to-digital samples that were measured during each period. [via]
Digital Sound Level Meter - [Link]
Here is my new Frequency meter who was done with a LCD’s cellular phone!!! This is a simple project. The Frequency is passing through an op-amp to convert it in a square wave. The ouput of the op-amp is feeding the 3*8 bits counter (24 bits) who can accumulate at a maximum of 16777216 count.
Frequency Meter – [Link]
The ESR Meter is basically an AC Ohmmeter with special scales and protective circuitry. It provides a continuous reading of series resistance in electrolytic capacitors. It operates at 100 kHz to keep the capacitive reactance factor near zero. The remaining series resistance is due to the electrolyte between the capacitor plates and indicates the state of dryness. Capacitor termination problems also show up plainly due to the continuous ohmic reading.
AC Ohmmeter – ESR Meter – [Link]
Some time previous to getting my ham license, I was at a friends house who showed me an LC (inductance) meter built from a kit. It was based on a PIC16C22A, and I certainly do like the PIC mcu’s, but decided I would embark on the task of re-engineering my own that uses an Atmel AVR chip, the Atmega168. It’s been a journey. Also, I am giving away for free the schematics, firmware, and source code as open source under the GPL.
Inductance meter - [Link]