【Training Camp】Moving little robot dog

printer_code.zip

printer_model.zip

BOM download

PCB_PCB_Thermal Printer_2022-09-23.pdf

PCB_PCB_Thermal Printer_2022-09-23.json

PCB_Thermal Printer_2022-09-23.pcbdoc

Gerber_PCB_Thermal printer.zip

Schematic_[Solicitation Order] Cloudline thermal printer_2022-09-23.pdf

SCH_[Solicitation Order] Cloudline thermal printer_2022-09-23.json

Sheet_1_2022-09-23.schdoc

61756

2021 Question A-Signal Distortion Measurement Device + Pick the Right Pair

Introduction: This signal distortion measurement device consists of MSP432E401Y, operational amplifier gain module, 5V regulated power supply, serial port screen display, and Bluetooth module. The measuring device extracts the harmonic information in the signal spectrum and calculates the normalized amplitude of each harmonic of the signal and the total harmonic distortion of the signal.

## Preface

The 2021 College Student Electronic Design Competition has been postponed to November due to the epidemic. Since all the team members have secured postgraduate degrees, and in order to show the spirit of perseverance to the lower grade students, we completed the competition within the time limit of 4 days and 3 nights with a normal attitude according to the postponed time, and won the second prize in the country. . We hope that this project with a TI microcontroller and a simple Android host computer can provide help to those who need it.

The structure of this system is very simple. In addition to the universal Bluetooth module, serial screen, and MSP432E401Y development board that can be applied for free, it only needs to connect a 5V power supply line with a USB connector and an SMA signal input line. The signal processing front-end only uses a piece of equipment. The chip TLV2316 can complete the parameter indicators required by the competition questions. The cost of making is low and it is suitable for imitation and reproduction.

## Team introduction

The members are all from Sun Yat-sen University, and they were all fourth-year undergraduate students in the class of 2018 at the time of the competition. Among them, 2 are majoring in optoelectronic information science and engineering, and 1 is majoring in electronic science and technology.

## Project Analysis

According to [Competition Title](https://res.nuedc-training.com.cn/topic/2021/topic_31.html), the basic requirement of this signal distortion measurement system is to be able to measure the fundamental frequency of 1kHz, The harmonic signal with an amplitude of 300mV-600mV, a theoretical THD of 3%-50%, and the highest fifth harmonic signal is sampled, THD analyzed, and displayed; the extension requires that the fundamental frequency is 1kHz-100kHz, the amplitude is 30mV-600mV, and the highest fifth harmonic signal is sampled. Harmonics are processed and displayed such as THD analysis and single-cycle time domain signal reproduction.

The competition question requires that the main controller and data collector used for signal distortion measurement must use TI's MCU and its on-chip ADC, and cannot use any data acquisition peripherals. Therefore, TI series chips are used as the main control, such as MSP430 and MSP432 series. The chip of the development board has extremely low power consumption and powerful scheduling and computing functions. For example, the MSP series chip has built-in TI RTOS and FPU unit to accelerate floating point computing functions. The development platforms include Energia, which is similar to Arduino, and CCS. In order to improve the ADC processing efficiency, CCS is chosen for microcontroller programming.

The extended part of the competition question requires the ability to analyze the fifth harmonic with a fundamental frequency of 100kHz, that is, 500kHz sampling. According to the Nyquist sampling rate, an ADC of at least 1Msps needs to be used for sampling. At the same time, because the system needs to perform DFT calculation and analysis signals, it has certain requirements for computing performance. Therefore, we chose MSP432E401Y, which has a main frequency of up to 120MHz, a maximum 2Msps, 12bit ADC, and an SRAM of up to 256KB, which meets the requirements of the competition. The system block diagram is shown below. ![Picture.png]

In terms of hardware, approximately three times the operational amplifier gain is used to amplify the input harmonic signal. The maximum input of the MSP432's ADC is 3.3V, with 12-bit accuracy. This system uses about three times the pre-gain and can achieve complete sampling of signals from 30mV to 600mV. A timer is used to control the sampling rate of the ADC, and DMA is used to accelerate ADC sampling to ensure the accuracy of the sampling moment. The measurement results are displayed through the serial port screen and Bluetooth.

In terms of software, for each measurement, the system first presamples at a frequency of 250kHz to determine the fundamental frequency to meet the sampling requirements for the fundamental frequency of 1-100kHz. The actual maximum sampling rate of the system is 1-2MHz. For the fifth harmonic of the fundamental frequency 100kHz, which is 500kHz, the maximum 2M signal can fully satisfy the signal reproduction. Therefore, the sampling rate is 20 times the fundamental frequency, that is, 20f0. Because the fundamental frequency is the highest energy part of the harmonic signal, the harmonic fundamental frequency f0 can be estimated from the DFT results. After selecting an appropriate sampling rate based on the fundamental frequency, then calculate the DFT spectrum analysis to obtain the fundamental frequency f0, and perform simple peak searches near 2f0, 3f0, 4f0, and 5f0 to obtain each frequency component.

## Schematic circuit design

We used Lichuang EDA to design the input signal amplification circuit. The amplification chip uses the existing TLV2316 chip in the laboratory. Its unit gain bandwidth of 10MHz is sufficient to meet the requirements of this question. Its low noise and low bias characteristics can ensure the quality of the input signal. We only designed and used a proportional amplification in the same direction with a gain of about three times. After amplifying the signal input from the signal source, it was directly connected to the ADC of the microcontroller for collection. Since the maximum ADC input of MSP432 is 3.3V with 12-bit accuracy, this system uses about three times the pre-gain and limits the power supply voltage of the op amp to the 3.3V single power supply output by the microcontroller development board to protect the microcontroller at the same time. Achieve complete sampling of signals from 30mV to 600mV. The circuit has a debug port for connecting to an oscilloscope for observation. The circuit used is as follows:

![image.png]
For the serial port screen and Bluetooth, the 74HC00 NAND gate chip is used to convert the 5V output level of the module into the 3.3V input required by the microcontroller. However, in this work, only the microcontroller sends data to the serial screen and Bluetooth in one direction, and does not involve data reception. The 5V input logic of the serial screen and Bluetooth is compatible with the 3.3V logic output of the microcontroller, so it is not actually used. The level conversion function designed here can be copied without making this part of the circuit. Just disconnect the RX of the microcontroller. This one-way output design also supports hot swapping without affecting the measurement of the microcontroller. The circuit is as follows:
![Picture.png]
## PCB circuit design

The signal front-end PCB based on the above circuit design is as follows. The left side is the input SMA socket, and the right side is the SMA socket after amplification and before amplification for observation (test (not connected at the time):
![image.png] The designed serial port adapter board PCB is as follows:
![image.png] Since the rapid plate making in the laboratory uses the method of thermal transfer + corrosive liquid, we only designed a single layer of panels , and try to ensure the connectivity of the signal lines. For power or ground lines that cannot be connected, manually fly the lines after plate making to ensure the integrity of the circuit.

## Physical display! [Full view of the work.jpg]
## The work is assembled

according to the above physical diagram. Just plug the two corroded and welded circuit boards directly into the microcontroller development board. The connection is stable and reliable. When testing, you only need to connect a USB power cable and SMA signal input cable.

### Test process

1. Connect the USB power cable and signal SMA cable, and start the output of the function signal generator.

2. Turn on Bluetooth on your phone and pair it with the Bluetooth-Slave device.

3. Open the PC APP on your mobile phone, select the device, and click "Connect" to start Bluetooth monitoring.

4. Change the signal of the function signal generator and observe the display on the serial port screen and mobile phone.

### Test results

For a low-frequency signal with a fundamental frequency of 1kHz, a peak-to-peak value of 400mV, and a 1-5th harmonic ratio of 1:0:0.20:0:0.15, the theoretical total harmonic distortion is 25%, and the measurement result is 25.37 %, the error is less than 5%.
![1k.jpg] For a signal with a fundamental frequency of 50kHz, a peak-to-peak value of 200mV, and a 1-5 harmonic ratio of 1:0:0:0.15:0.08, the theoretical total harmonic distortion is 17%, and the measured result is 16.32 %, the error is less than 3%.
![50k.jpg]For a signal with a fundamental frequency of 100kHz, a peak-to-peak value of 40mV, and a 1-5th harmonic ratio of 1:0:0:0:0.1, the theoretical total harmonic distortion is 10%, the measurement result is 10.00%, and the error is less than 3% .
![100k.jpg] In summary, the specific numerical indicators of the signal can meet the requirements of the competition question.

## All program design

codes have been packaged, see the attachment dist.zip:

* start53 - CCS project content, you need to install the simplelink_msp432e4_sdk_4_20_00_12 version of the development kit
* THDMeasure - Android Studio project folder
* app-release.apk - compiled Android APP Host computer (display results, draw images)
* The national competition has phase frequency-correction.HMI - serial port screen design file

## Summary

In the preparation and competition of this national college student electronic design competition, the team independently completed the system software and hardware parts The design, as well as the testing and improvement of the corresponding plan, completed the competition questions. Accumulated certain experience in electronic design and microcontroller system application.

Demo video.mp4

app-release.apk

Design report.pdf

dist.zip

BOM download

PCB_PCB_2021-Bluetooth serial port adapter board_2022-09-23.pdf

PCB_PCB_2021-Bluetooth serial port adapter board_2022-09-23.json

PCB_2021-Bluetooth serial port adapter board_2022-09-23.pcbdoc

Gerber_PCB_2021-Bluetooth serial port adapter board_2022-09-23.zip

PCB_PCB_2021-Op Amp_2022-09-23.pdf

PCB_PCB_2021-op amp_2022-09-23.json

PCB_2021-Op Amp_2022-09-23.pcbdoc

Gerber_PCB_2021-op amp_2022-09-23.zip

Schematic_2021 Question A-Signal Distortion Measurement Device + Pick Any Pair_2022-09-23.pdf

SCH_2021 Question A-Signal Distortion Measurement Device + Pick the Right Pair_2022-09-23.json

2021 Question A-Signal Distortion Measurement Device + Pick the Right Pair_2022-09-23.zip

61757

Motor round trip automatic control analog circuit

Introduction: Motor round trip automatic control analog circuit

Motor round trip automatic control analog circuit

BOM download

PCB_PCB_Motor round trip automatic control analog circuit_2022-09-23.pdf

PCB_PCB_Motor round trip automatic control analog circuit_2022-09-23.json

PCB_Motor round trip automatic control analog circuit_2022-09-23.pcbdoc

Gerber_PCB_Motor round trip automatic control analog circuit.zip

Schematic_Motor round trip automatic control analog circuit_2022-09-23.pdf

SCH_Motor round trip automatic control analog circuit_2022-09-23.json

Sheet_1_2022-09-23.schdoc

61758

Three-phase motor forward and reverse analog circuit

Introduction: Three-phase motor forward and reverse analog circuit

Three-phase motor forward and reverse analog circuit

BOM download

PCB_PCB_Three-phase motor forward and reverse analog circuit_2022-09-23.pdf

PCB_PCB_Three-phase motor forward and reverse analog circuit_2022-09-23.json

PCB_Three-phase motor forward and reverse analog circuit_2022-09-23.pcbdoc

Gerber_PCB_Three-phase motor forward and reverse analog circuit.zip

Schematic_Three-phase motor forward and reverse simulation circuit_2022-09-23.pdf

SCH_Three-phase motor forward and reverse simulation circuit_2022-09-23.json

Sheet_1_2022-09-23.schdoc

61759

Lichuang training camp colorful rotating table

Introduction: Based on Xinyuan CW32F030C8T6 as the main control, it drives a four-phase brushless motor to achieve variable speed rotation of the table. The MCU simultaneously drives 8 RGB lamp beads to achieve colorful lighting effects.

Based on Xinyuan CW32F030C8T6 as the main control, it drives a four-phase brushless motor to achieve variable speed rotation of the swing table, and the MCU simultaneously drives 8 RGB lamp beads to achieve colorful lighting effects. The table can be placed to display various collectible figures for full appreciation.

SCH_Rotating RGB Ornament_2022-05-26.json

PCB_PCB_Rotating RGB ornament_2022-05-26.json

WeChat picture_20220615210905.jpg

WeChat picture_20220615210911.jpg

PCB_PCB_PCB_Rotating RGB Ornament_2022-05-26_2022-11-05.pdf

BOM_Board1_PCB_PCB_Rotating RGB Ornament_2022-05-26_2022-11-05.xlsx

Altium_Lichuang training camp colorful rotating table_2022-11-05.zip

PDF_Lichuang Training Camp Colorful Rotating Table_2022-11-05.zip

BOM_Board1_Training Camp Colorful Rotating Table_2022-11-05.xlsx

61760

electronic