Brushless electric motor (BLDC motors) are synchronous motors that are powered by a DC electric source via an integrated inverter/switching power supply, which produces an AC electric signal to drive the motor.
Driving that IC is pretty simple, expecially if you have a dedicated SPI hardware interface, like many microchip has. The ATmega8, used in this example has a dedicated SPI Control Register (SPSR) that one can use to setup the SPI interface. This library can drive more then one MCP49XX of the same series at the same time, this is done just by selecting the chip using a SS channel for each one.
This project describes a simple low-current meter I devised to check the sleep current of different microcontroller circuits, such as ones based on AVR microcontrollers. It’s capable of measuring currents of between 10µA and 30nA with reasonable accuracy, using an ATtiny84 and a few other low-cost parts
tinyPulsePPG, an ATTiny85 Pulse Oximeter with Photoplethysmogram (PPG) display by Jeff Magee:
This project implemented on an ATTiny85 displays a moving Photoplethysmogram together with pulse rate and estimates of SpO2 – blood oxygen percentage. It uses an SSD1306 128×32 OLED display and a Max30102 sensor. It is emphasised that this should not be used for medical purposes. The computation of SpO2 is very approximate and not calibrated in any way. The project is an exercise in software and hardware parsimony.
This tuner circuit is a quick prototype which I build to test the RDA5807M FM radio tuner IC. RDA5807M is a single-chip tuner IC with RDS and MPX decoder, and it equipped with I2C interface for control. This receiver builds around Atmel’s ATmega16A 8-bit MCU. The output stage of this design consists of AN7147N, 2×5.3W audio power amplifier.
HX711 is a precision 24bit ADC IC designed for weigh scales and industrial control applications to interface directly with a bridge sensor.
A load cell is a transducer that is used to create an electrical signal whose magnitude is directly proportional to the force being measured.
The library you can find here is usefull to implement a weigh scale using the HX711.
I have only two aims while trying this. The receiver should get powered by the transmitter continuously. I should be able to control the power received by adjusting the error packets, in my case I am trying to keep received voltage always 10v.
There are lot more but I am only interested in this two features for now, so I will not be following the complete Qi specs described on the WPC documents, by the way, it worked for me without any issue. This is purely experimental.
The main objective of this project is to design a maintenance free and low-cost light which automatically turns on and off at the predetermined time of the day.
To meet the above requirement I designed this controller using ATmega8 MCU and DS1307 RTC. The driver stage of this light controller is intended to work with commonly available 7W LED modules.