user “abbtech” writes:
The heart of the PWM Fan Controller is a PIC 12F675 microcontroller. This microcontroller is reading the analog output of a LM35 temperature sensor using a ADC (analog to digital converter) . The resulting digital value is converted to a temperature and a fan is powered proportionally to how hot the sensor is.
PIC 12F675 PWM Fan Controller - [Link]
This project is a PWM Fan controller based on PIC18F25K20. It offers a variable speed control, low acoustic noise, reliability, long lifetime, low power consumption, protection features. The MCU get the temperature from the sensor (D18B20), and after will do a conversion Celsius degrees and then it´s generated a PWM on PORTC.2 with 6 different levels.
PIC PWM Fan controller - [Link]
David Carr build a 3-axis CNC milling machine on the cheap. His machine is build on wood, costs around 90$ and can mill wood, steel or even small PCBs. Project schematics and drawing can be found on his website below. [via]
Build a 3 axis milling machine for under $100 - [Link]
This project shows an 3-Wire DC Fan rpm regulator with intelligent duty cycle adjustment. The circuit will try to maintain the preselected rotation speed by adjusting duty cycle and receiving feedback from fan output. Check full project details on the link below.
PIC 3-Wire Fan RPM Controller - [Link]
To control the direction of a motor you have to be able to control the current flow throught it. To do this specialized ICs are used intergrating a circuit called H-Bridge. In the link below you can find a tutorial on how to use Texas Instruments L293NE or Texas Instruments SN754410. [via]
How to use L293NE to control a motor - [Link]
The EasyDriver is a simple to use stepper motor driver that is controlled using 5V pulses. There is two inputs, one for setting the direction and another for controlling steps of motor. It can drive bi-polar motors up to 750mA/phase. Power supply range from 7V to 30V and it is based on Allegro A3967 driver chip.
EasyDriver Stepper Motor Driver - [Link]
DTMF-remote – Activate relays with your smartphone - [Link]
Motors are everywhere! From robots to remote-controlled cars, any DIY hobbyist will very quickly find themselves trying to control a motor with a microcontroller. Luckily, simple control of a brushed DC motor is easy, and only requires a few components. Have you ever tried spinning a motor with the contacts connected together? Or seen sparks as you connect and disconnect your motor? What consequences do those things have on how you control the motor and protect your other circuitry? There are instructions out there that allow you to build a complicated motor controller that might work, however in this video tutorial we take a step back and go over some of the very basic things you need to think about when using motors, because so much is dependent on understanding the details of your specific situation. From stall current, to back-EMF, we present 9 small experiments you should try to get a better sense of how the motor is going to behave in your circuit. The tutorial also goes over how to connect a simple motor to a microcontroller, and turn it on and off using a 2N7000 n-channel MOSFET and a few other parts. The topic of power electronics goes much, much deeper. Often times, it is necessary to consider power dissipation, switching frequencies, gate capacitance, and when trying to drive a motor in both directions, an H-bridge is required. However, we have to start somewhere, and there is nowhere better to start than with experimentation!
Using motors with microcontrollers - [Link]
This is a nice example of scavenging parts from an inkjet printer to make cool stuff. It uses an Arduino and a Motor Shield to control the DC motor. The web site has a lot more information and the source code to get you started. [via]
Using a DC motor as a servo with PID control – [Link]