DDS signal generator with AVR sine, square, ECG 8Mhz

DDS signal generator with AVR sine, square, ECG 8Mhz

DDS signal generator with AVR circuit with Atmega16 microcontroller with BNC output. One square wave output up to 8MHz and another DDS output with sine wave, square, triangle, ECG, Noise, Inverted Sawtooth. The offset can be adjusted from +V to -5V, the amplitude can be adjusted from 0 to 10V by potentiometer. With keys to access the functions.I have already posted a PTH component version and this time we used SMD components, plus bigger keys, BNC connector output, 16 × 2 LCD and adjustment potentiometers.

The DDS output is used for all complex signals generated through the R2R resistor network and is adjusted by LM358 offset and amplitude regulation circuits. Two potentiometers control the offset and amplitude.

The power supply I used LM317 voltage regulator set to 9V output and a symmetrical power supply generator by ICL7660 to power the operational amplifier. To power the Atmega16 microcontroller, I used LDO LD7550 voltage regulator. If you prefer, you can configure the Lm317 to run at 12V.

Get new posts by email:

The crystal is type SMD-3225-4P, the Lm358 IC must be original, the symmetrical voltage generator can be original Renesas or similar, the voltage regulators can be of any brand.

Buy equivalent circuit in AliExpress

Buy equivalent circuit in Banggood

DDS signal generator schematic

Schematic Circuit Dds Signal Generator With Avr
Schematic Circuit Dds Signal Generator With Avr

DDS signal generator PCB

Pcb Printed Circuit Board Top Dds Signal Generator
Pcb Printed Circuit Board Top Dds Signal Generator
Pcb Bottom Printed Circuit Board Dds Signal Generator
Pcb Bottom Printed Circuit Board Dds Signal Generator
View Of Components Top Dds Signal Generator
View Of Components Top Dds Signal Generator
Top Component View Dds Signal Generator Bottom Part
Top Component View Dds Signal Generator Bottom Part

Features DDS signal generator sine function, square, ECG 8Mhz

  • High-speed (HS) output signal up to 65.534Hz (Sine, Square, Triangular, Sawtooth, and others) or 8 MHz at high-speed (Square Wave) output
  • DDS with variable amplitude and offset.
  • DDS signals: sine, square, Sawtooth, Triangle, ECG, and noise.
  • 2×16 LCD – Intuitive menu with 6 keys.
  • Frequency setting steps: 1, 10, 1000 and 10000 KHz
  • Restores the last setting after power-up.
  • Has two outputs – One for DDS signal and one for high speed.
  • Power supply with LM317 IC, and can use higher voltage source up to 35V.
  • Symmetrical source for the operational amplifier using ICL7660, to generate +9 and -9V.
  • Power supply: 12 to 35V DC
  • DDS signal frequency: 1 to 65.534Hz
  • Waveforms: Sinusoidal, Square, Triangular, Sawtooth, Inverted Sawtooth, ECG, Noise
  • HS Signal Frequency: 1, 2, 4, 8 MHz
  • Microcontroller used: Atmega16A
  • Setting: Offset and amplitude
  • Display: 16 × 2 LCD with backlight
  • Consumption: About 55mA with backlight

To program the microcontroller, you can use some TQFP44 to AVR adapter or, via ICSP, you can use professional recorders like Minipro or even the low cost Atmel USBasp ISP.

https://www.youtube.com/results?search_query=USBASP+AVR+

The fuse configuration is:
Low: 0×CF
High: 0×59

Check:
OCDEN SPIEN BOOTSZ1 BOOTSZ2 SUT1 SUT0

BOM for mounting the function generator board

Last Update: 02/03/2023 16:01

PartValueDescriptionAmount
Resistors
R3, R12, R13, R14, R15, R16, R17, R1810k103 or 1002 — SMD 0603 1%8
R11.5k152 — SMD 06031
R22402540 — SMD 06031
R4, R5, R6, R7, R8, R9, R10, R11, R1920k203 or 2002 — SMD 0603 1%9
R20, R23100k104 — SMD 06032
R21100101 — SMD 06031
R224.74R7 — SMD 08051
R2412k123 — SMD 06031
P11k102 — Potentiometer 1K — Offset1
P250k503 — Potentiometer 50K — Amplitude1
P310KTrimpot SMD de 3 mm — BOURNS TC33X-2-103E or equivalent
Capacitors
C1, C2, C5, C6, C10, C11, C12, C1510uF/16VTantalum Capacitor 3216 (CASE-A-3216)8
C410uF/50V1206 SMD Ceramic Capacitor1
C3, C7, C8, C9, C13, C14, C16, C17, C18, C19100nSMD 0603 ceramic capacitor – C3 50V or more10
Semiconductors
IC1LM317Adjustable Positive Voltage Regulator – TO-252-2 (DPAK)1
IC2ICL7660Renesas Symmetrical Voltage Generator – SOIC-81
IC3HT7550Positive voltage regulator 5V ±2% tolerance – SOT891
IC4Atmega16aAtmega Microcontroller (Microchip) TQFP441
IC5LM358Operational Amplifier – SOIC-81
LCD1LCD-HD447804Display LCD 16 × 2 with backlight1
Q116MHzCrystal — SMD-3225-4P1
Miscellaneous
S1RESETTactile key – B3F-40XX or equivalent 12×12×7.3 mm – Reset the board (optional)1
S2UPTouch key – B3F-40XX or equivalent 12×12×7.3 mm – UP menu1
S3RIGHTTactile Key – B3F-40XX or equivalent 12×12×7.3 mm – Right menu1
S4START/STOPTactile key – B3F-40XX or equivalent 12×12×7.3 mm – Start/Stop1
S5LEFTTactile Key – B3F-40XX or equivalent 112×12×7.3 mm – Left1
S6DOWNTactile key – B3F-40XX or equivalent 12×12×7.3 mm – Below1
J112VDC JACK1
J2DDSBNC connector – DDS output1
J3HSBNC connector – HS output1
JP1AVR-ISP-6ICSP connector – For programming the Atmega16 – Can be 2 rows of pin header.1
Solder, Wires, PCB, Box, Power Supply.
Download the files for this PCB assembly in Gerber, PNG, Postscript, and PDF – All for free.

Download

Mirror

See also the version with PTH components

Detail of this project and source code on the Science Prog site

 

 

How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

As you found this post useful...

Share on the social networks!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Photo of author
About the author
Xtronic.org blog author. Electronics technician for the technical school of Brasilia - Brazil. Interested in electronics, circuits and technology in general.
Share:

Leave a Comment