This is an example of a simple and cheap milliohmmeter that can be made by every maker. The core of the circuit are a current source (LT3092) and a current sense (INA225): a costant current flows through the milliohm resistor under test and the voltage at the current sense output gives the value of the resistor (V=R*I). Continue reading
Nowadays almost every electronic gadgets are powered or recharged by a USB port (full size, mini o micro) as well as many of consumer products we use every day, including our smartphone. To recharge or give power to such products, there are many portable rechargers which have a rechargeable lithium battery and the electronics necessary to convert the battery voltage to 5V and to recharge the internal cell. The cost of these smart chargers is very affordable but we’re hardware makers, aren’t we? So why don’t to do it by ourselves to give power to our Raspberry Pi, arduino or Beaglebone black? We’ll show you a possible way to design one of these intelligent portable power supply. 
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Microchip: Application Notes- TB3264 - Using the Universal Timer (UTMR) Module
- TB3267 - Channel Sequencing and Context Saving Using the ADC with Computation and Context Switching Module
- AN3640 - Low IQ Boost Converters for Monitoring and Efficient Utilization of Alkaline Batteries
- TB3265 - Getting Started with SPI Using MSSP on PIC18
- TB3270 - Getting Started With PWM Using CCP on PIC18
- Open Electronics
- mbed