Black Star Apollo 100 frequency counter

Preamble

I saw this old Apollo 100 Universal Counter Timer. However, the B channel does not work apparently. This is clearly a fairly common issue, as another chap was also looking for a solution and/or service manual, Black Star Apollo Frequency Counter, back in 2014.

This is probably due to the reduced input of channel B and blown input stage (front end)

Continue reading Black Star Apollo 100 frequency counter

Build your own frequency meter ATtiny2313

Preamble

Following on from Frequency Abacuses, from Re: Ten Dollar Frequency Counter’s – Thread #2, there is a link, Schaltungsbeschreibung ‘reziproker Frequenzzähler 0,0025Hz-50MHz’, to building your own frequency meter:

Do any of these come with a simple serial port output of the reading? With let’s say a 1 per second dump at 9600 baud?
That would be immensely more useful than a display, really.

Are you able to programm an ATtiny2313? If yes you can use ‘fmeter20.zip’ to get a frequency counter 0,005 Hz – 1 MHz (up to 200 MHz with prescaler). With 20 MHz Xtal baudrate is 38400. The LCD is not necessary at all.
http://mino-elektronik.de/fmeter/fmeter.htm

You can find another low frequency counter using Arduino UNO board with serial data output. First version 0,016 Hz – 250 kHz and 2. version with internal prescaler up to 7 MHz: http://mino-elektronik.de/fmeter/fm_software.htm#bsp7

A simple 5-digit counter is shown here: http://mino-elektronik.de/fmeter/fm_software.htm#bsp13

Sorry for german description.

Below is the German translation… and the ATtiny2313 version is at the bottom of the page.

Continue reading Build your own frequency meter ATtiny2313