Raduino
The Raduino is a DDS VFO based on the Silicon Labs 5351A DDS Chip, an Arduino Nano Module, and a parallel LCD display.
The Si5351A is controlled by the Nano via an I2C bus and provides three clock outputs, one of which is currently used. The Wire.h library handles the low level I2C bus commands and the si5351.h library handles the low level interface to the DDS chip.
The LCD Display is a common parallel interface LCD module used in 4 bit mode to conserve I/O pins at the cost of two transfers per character. These modules typically use the Hitachi HD44780 display controller and command set. The LiquidCrystal.h library handles the low level interface to the LCD module.
The Arduino Nano with the Raduino.ino sketch(aka program) turns all of these parts into a DDS VFO. The Nano is based on the AVR ATmega328 8-bit processor running at 16 MHz. The Nano has 32KB Flash, 2KB SRAM, and 1KB EEPROM memory. Nano I/O consists of 14 digital pins and 8 analog pins. Note that Arduino I/O pin numbers are an abstraction and don't correspond to chip or module pin numbers.
Two headers provide access to the various DDS VFO signals. The 16 pin "Oscillators" header provides access to the three clock outputs and Nano digital I/O pins D2-D7. The 8 pin "Controls" header provides access to Nano analog pins A0-A3 and A6-A7(A4(SDA) and A5(SCL) support the I2C bus and are not brought out on either header). Note: Analog pins, except A6 and A7, may also be used as digital I/O pins.
The Nano pin assignments are as follows:
???? 1??? D1/TX/USB???????????? USB Interface to PC, Downloading and Serial Comms
???? 2??? D0/RX/USB???????????? USB Interface to PC, Downloading and Serial Comms
???? 3??? RESET
???? 4??? GND
???? 5??? D2?????????? OC6??? ? ? External Interrupt Pin - Spare(?)
???? 6??? D3?????????? OC5???? ?? External Interrupt Pin - Spare(?)
???? 7??? D4?????????? OC4???? ?? TX_LPF_SEL
???? 8??? D5?????????? OC3???? ?? CW Key(future)
???? 9??? D6?????????? OC2???? ?? CW Tone(future)
??? 10??? D7?????????? OC1??? ?? TX/RX(future)
??? 11??? D8?????????? LCD4?? ?? LCD RS - Parallel LCD Module in 4-bit mode
??? 12??? D9?????????? LCD6??? ? LCD R/W
??? 13??? D10???????? LCD11??? LCD D7
??? 14??? D11???????? LCD12??? LCD D6
??? 15??? D12????????? LCD13??? LCD D5
??? 16??? D13????????? LCD14??? LCD D4
??? 17??? 3V3
??? 18??? AREF
??? 19??? A0?????????? CC8??? ? ? Spare(?)
??? 20??? A1?????????? CC7??? ? ? Analog Keyer(future)
??? 21??? A2?????????? CC6???? ?? Calibrate Push Button - Digital w/pullup
??? 22??? A3?????????? CC5??? ? ? Function Push Button? - Digital w/pullup
??? 23??? A4/SDA??? SI5??? ? ? Si5351A I2C SDA
??? 24??? A5/SCL??? SI4???? ?? Si5351A I2C SCL
??? 25??? A6?????????? CC2??? ?? PTT(future)?????????? - Digital w/pullup
??? 26??? A7?????????? CC1??? ?? Tuning Pot Wiper????? - Analog
??? 27??? +5V
??? 28??? RESET
??? 29??? GND
??? 30??? Vin
??? OC? - Oscillators Connector
??? CC? - Controls Connector
??? LCD - LCD Connector
??? SI? - Si5351A Pins
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