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Showing posts from August, 2019

USB Morse Keyer

USB Morse Keyer is a microcontroller-based auto keyer project with following features: USB / straight key / iambic key inputs. Support for both standalone and USB operating modes. 64-character USB typeahead buffer and 6-character Morse key typeahead buffer. Support 5, 10, 15 WPM. 6-page message memory. 1W Audio output. Audio and PTT output interfaces. 32 character display  Final view of the USB auto keyer. The USB interface of this unit is designed to work with most of the operating systems. It emulates a virtual serial terminal to transfer keystrokes to the keyer. In most of the operating systems, this interface works without installing any additional device drivers. To submit keystrokes user can use any serial terminal software such as PuTTY , Hyper Terminal , Minicom , etc. This keyer is designed to work with 7V to 16V DC input voltage. The most recommended working voltage is 9V. The bottom side of the USB auto keyer. To reduce the dimension of the PCB t

Verification module for PT8211 DAC

This quick post is about the verification script which I did to test the PT8211 DAC functionality. This script is designed to work with Arduino boards and, I tested with Arduino Due and Arduino Mega 2560 boards. The script is self-explanatory, and it emulates the I2S interface and communicates with the PT8211 DAC. The output waveform of PT8211 on Arduino Due board. With this script, PT8211 generate sine wave in both channels. The frequency of the waveform is dependent on the clock frequency of the Arduino board. In Due board, PT8211 generates 0.052kHz sine wave on both channels. Connections between PT8211 and Arduino. The test setup is quite straightforward. I2S and power pins of PT8211 need to connect to the Arduino board in the following order: Serial clock ( BCK ) - Pin 22 Channel selector ( WS ) - Pin 23 Data ( DIN ) - Pin 24 VCC - 5V (Mega 2560 board) 3.3V (Due board) GND - GND Left and right channels of the DAC is connected to oscilloscope or frequenc