Introduction

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This project integrates the signal generator of the "Lao Liu Aitong" solution, the USB virtual oscilloscope of "liushuai", and adds an SD NAND particle and card reader chip to realize USB storage.
Can be cut according to needs.

USB virtual oscilloscope

The USB oscilloscope uses STMF103C8 as the main control, on-chip ADC sampling, and USB analog serial port to communicate with the host computer. The performance is not strong, but the structure is simple and easy to use.
On the basis of the original project, operational amplifier and diode protection were added, which on the one hand increased the input impedance and on the other hand prevented overvoltage from damaging the device.

Original project address

MCU end engineering
host computer engineering

Basic parameters

Maximum sampling rate: 70KSPS
Sampling depth: 6144
Measurement range: 0-3.3V
Input impedance: 1M ohm
FFT spectrum analysis

use

Burn the firmware in, then connect the USB, open the host computer, and select the corresponding virtual serial port.

Signal generator

Using the "Old Liu loves to tinker" plan, everyone is familiar with this boss. An STC15 plus peripheral circuits is low cost.
Based on the original project, the square wave and sine wave output channels were combined, and relays were used to control the signal paths. At the output end, a potentiometer can be used to control the amplitude, and movement can be used to increase the driving capability.
In order to realize signal switching, the STC15 program has been modified. Please use the modified version of the signal generator program.

Original project address

Lao Liu signal generator

Basic parameters

Waveform: square wave, sine wave
Square wave: 1-2MHz, adjustable duty cycle
Sine wave: 1-10kHz
Amplitude: 0-5V
Output impedance: 50ohm

use

If you are not interested in the program, just burn the attached Function_Generator.hex directly.
The model is STC15W4K, and the clock frequency is 24M.
Note: Signals that are too small may be distorted due to the output range of the op amp.

USB memory

To be honest, I don't know why I want to do this. For this I used a piece of GL823K, SD nand, SL2.1A.
Maybe it can be used as a USB flash drive?

Update history

-Correction: STM32 D+ adds a pull-up resistor
-Correction: The oscilloscope input port uses a diode with smaller leakage current
-Optimize the silk screen position