This is a very simple and easy to build programmer for Atmel microcontrollers from AVR family. The microcontrollers must support serial programming. This programmer is connected to a PC through the RS232 serial interface and can be used with the PonyProg or Avrdude software programmer. The programmer is quite simple and it is based on the SI-Prog from the author of PonyProg software. The Zener diodes D2, D3 with the resistors R2, R3 reduce the voltage from the ouput pins DTR, RTS on the serial port to around 5V which is suitable for microcontroller (MOSI, SCK). MISO signal is connected directly to the input CTS pin. The Zener diode D1 with the resistor R1 drive the NPN transistor T1, which controls RESET signal. The AVR microcontrollers are in reset when the signal has low level. The resistor R5 works as a pull-up for reset signal. The resistor R4 helps to close the transistor T1. The programmer has standard 10 pins header.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]