An ATmega brushless sensorless motor driver v02

Davide Gironi has posted an update on his ATmega brushless sensorless motor driver project we covered previously:

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.

See the full post on his blog here.

Check out the video after the break.

Drive an MCP49XX series DAC with an AVR ATmega

Davide Gironi writes:

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.

See the full post on his blog.

Check out the video after the break.

ATTiny85 Pulse oximeter with photoplethysmogram (PPG) display

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.

Project info on GitHub.

FM stereo radio receiver with RDS

Dilshan Jayakody has published a new build:

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.

See the full post on his blog.

HX711 load cell amplifier library for AVR ATmega


A HX711 load cell library for AVR ATmega:

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.

More details on Davide Gironi’s blog.

Check out the video after the break.

Qi wireless power receiver from scratch


Vinod made a Qi wireless power receiver using Attiny13, that is available on GitHub:

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.

See the full post on his blog.

Check out the video after the break.

Programmable light controller


Dilshan Jayakody published a new build:

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.

More details  on his blog.