PI Zi Heng Bi monthly No.28

Time:2021-4-21

Bimonthly: No.28

Here are some useful and interesting projects in the embedded field / Tools and some hot news, the Lunar New Year is divided into 24 solar terms, hoping to release an issue on time on the day of each festival.

This journal is an open source projectJayHeng/pzh-mcu-bi-weekly)Welcome to issue, contribute or recommend the embedded things you know.

Review of last issuePI Zi Heng Bi monthly: 27th issue

A little chatter

The vernal equinox happened last Saturday. Today in history: on March 28, 1271, Zhongdu in the capital was changed to Dadu and officially became the capital of the Yuan Dynasty.

This issue contains 1 piece of information, 4 items, hope to help you!

Information

1. Dialog introduces low power Bluetooth noise reduction headset application scheme

Recently, dialog has launched a low-power Bluetooth headset noise reduction scheme. The following schematic diagram shows the various hardware components required by the scheme. The color part of dialog can provide relevant chip support.

The ability of Bluetooth audio headset to listen to music or conversation can be greatly improved by integrated ambient noise cancellation (ANC). This technology eliminates the unwanted background noise in the received audio, and also minimizes the interference of the transmitted audio signal. Integration minimizes latency and power consumption, and separates ANC functions from any operating system. The integrated USB battery charger eliminates the need for dedicated components, allowing the design to have the smallest BOM and provide the highest performance.

Information home page:https://www.dialog-semiconductor.com/interactive-application-diagram/connected-consumer/bluetoothble-ambient-noise-cancellation-anc-headset

Project category

1. Linglong GUI – Open source GUI for SCM level low price products

Linglong GUI is an efficient interface development solution. Instead of serial port screen and configuration, the cost of the product is reduced, and the software and hardware of the product are controlled independently. Supporting interface development software, graphical editing interface, generating C code, directly combined with user product code. Download upgrade software and bootloader to solve the problem of product upgrade and image download.

Project home page:https://gitee.com/gzbkey/LingLongGUI

2. Voltage current calibrator – open source voltage and current calibrator (5.5 bits)

Spo256al2 is an open source project on elektormazine, which is not difficult. It is a five and a half bit voltage and current calibrator that can DIY itself. The output voltage is ± 10V, and the single step adjustment is 20uv. The current is 0 to 40 Ma, and the single step adjustment is 100 Na.

Device selection: reference voltage max6350esa, DAC ad5791, instrument amplifier ad8276, pzt1222 and ad8677

Project Home :https://www.elektormagazine.com/labs/voltage-current-calibrator-0-to-10v-and-0-to-40ma-0001

3. Audio spectrum visualizer Analyzer – dynamic music beat spectrum display

Arduino based 32 frequency division, dynamic music beat spectrum analyzer supports a variety of ways of audio input, and is equipped with four dot matrix screens. It can display the spectrum information of music in real time, and jump with the dynamic beat of music in real time. This design is easy to make and has strong playability. If you are interested in audio processing, you can play it.

Project home page:https://github.com/shajeebtm/Arduino-audio-spectrum-visualizer-analyzer/

The spectrum display has the following five features:

1. Using easy to install libraries Arduino FFT and MD_ MAX72xx。

Atmega328p has built-in ADC, which can convert the input audio signal into digital signal. The sampling clock frequency of ADC is 38.46khz, which is realized by configuring the prescaler of ADC to 32. The sampling frequency of 38.64khz means that the input frequency of digital samples can be as high as 19.32khz, which satisfies the Nyquist sampling theorem. Arduino FFT library is the core code to convert input analog signal into spectrum. This library is easy to use and supports points from 16 to 128. The LED matrix used in this project is 32 columns × 8 rows_ The max72xx library makes the display control unit very easy.

4. Garden monitor – irrigation system based on raspberry pie

The Internet of things drip irrigation system based on raspberry pie uses the Internet of things to monitor and maintain the normal growth of plants. It combines sensors with plants to monitor the status of plants in real time. With app software, it can make corresponding operations according to the feedback data to ensure the healthy growth of plants. In the whole system, raspberry pie collects data information, such as light, temperature and humidity, and soil moisture content, and then transmits the data of various sensors to the cloud database for processing. The smart phone application is used to support access at any place, and the user sends commands (such as the status of the water pump) to the drip irrigation system on the mobile phone app and executes the relevant commands.

Project home page:https://make.quwj.com/project/130

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