Tag Archives: Function Generator

ATtiny85 Function Generator

David Johnson-Davies build a tiny function generator based on ATtiny85 microcontroller. He writes:

This article describes a simple function generator based on an ATtiny85. It can generate triangle, sawtooth, square, and rectangular waves, a pulse train, and noise. The frequency can be adjusted using a rotary encoder between 1Hz and 5kHz in steps of 1Hz, and the selected waveform and frequency is displayed on an OLED display.

This project really puts the ATtiny85 through its paces; it’s generating 8-bit samples at a 16kHz sampling rate, decoding the rotary encoder, switching between waveforms, and updating the OLED display via I2C.

ATtiny85 Function Generator – [Link]

Teardown & Repair of a SRS DS345 30MHz Synthesized Function Generator

In this episode Shahriar investigates a peculiar problem with a SRS DS345 function generator. The instrument does not appear to produce the correct output signal frequency. After some investigation it becomes clear that a few of the display digits are not active which hide the actual frequency settings. The problem is traced to a broken resistor on the display driver. The schematic of the instrument shows that the resistor is responsible for strobing the affected seven-segment digit. After the repair, the instrument’s performance is verified including the OCXO accuracy.

Teardown & Repair of a SRS DS345 30MHz Synthesized Function Generator – [Link]

Protek B8010FD Function Generator Teardown and repair

Micah Elizabeth Scott @ yoututbe.com does a teardown, repair, and mini-review of the 2007 vintage Protek B8010FD.

Protek B8010FD Function Generator Teardown and repair – [Link]

MAX038 Function generator


Milen @ instructables.com has designed a Function Generator based on the popular MAX038 and is controlled by ATMega328PU. Signal characteristics are displayed on a LCD screen.

The digital features of the function generator were performed by one Atmega328 chip. Its functions are the following:
controls the frequency range selection
controls the signal type (sine, rectangular, triangular, sawtooth)
measures the amplitude of the signal
measures the DC offset
measures the frequency of the signal
measures the THD of the sine signal in the audio range (this still have to be implemented)
displays all this information on a character 16×2 LCD display.

MAX038 Function generator – [Link]

Easily measure diode capacitance and reverse recovery

1N4002 zero Vf bias ll 120pF

Glen Chenier @ edn.com wanted to find out the characteristics of an unknown diode to be able to replace it with an equivalent one so he decided to make some measurements using his test equipment. In this article he show us how to measure the junction capacitance, Cj, and reverse recovery time Trr of a diode using a function generator and a 100Mhz oscilloscope.

Easily measure diode capacitance and reverse recovery – [Link]