741 PWM_Sinewave_UART
741 : PWM_Sinewave_UART
- Author: Luis Gerardo Avila
- Description: This project is a PWM signal generator that creates a sine wave, with frequency variation between 100 Hz and 700 Hz with steps of 100 in 100 Hz, which is manipulated through a UART interface
- GitHub repository
- Open in 3D viewer
- Clock: 25000000 Hz
How it works
Through UART communication, a number from 1 to 7 is sent, indicating the frequencies set in the code, which are from 100 Hz to 700 Hz, then through a pin I generate a PWM signal which varies in time to generate a sine wave of the frequency that was requested.
How to test
Only physical tests were carried out with the circuit, a Bluetooth antenna was added to the UART communication port, and a low pass filter was added to the output of the system to improve the signal a little and then it was measured with the oscilloscope and I verify that it delivers the requested frequencies.
External hardware
- Bluetooth HC05
- Oscilloscope
- A low pass filter
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | uart_rx | uart_tx | |
| 1 | |||
| 2 | pwm_outx | ||
| 3 | |||
| 4 | sw_11 | ||
| 5 | sw_01 | ||
| 6 | rst1 | ||
| 7 |