The accu cycler project presented here is an excellent solution for charging and discharging NiCd and NiMH accumulators for R/C modelers and others who make use of these accumulator types. With its performance it is very close to the many of the commercial products available on the market. The 'power' part of the design is not a common choice in similar applications, having in mind of its size and energy dissipation, but it is very easy to understand its principles of operation even for beginners in electronics. The 'intelligent' part of the design communicates with PC using serial port providing additional process visualization. The process graph is saved to on-board EEPROM memory and it is possible to download the data to PC even when the charging/discharging process has finished.
The screenshot of the Accu Cycler application:
The Accu Cycler application is available for the download here.
The firmware for the 16F877A chip used in this design is given in the form of Basic source program that has to be compiled with PIC Simulator IDE integrated Basic compiler to get the HEX file ready to be programmed into the microcontroller.
This design can be used without any hardware modifications with 40-pin microcontrollers from 18F family. Here is the firmware for the 18F452 chip in the form of Basic source program that has to be compiled with PIC18 Simulator IDE integrated Basic compiler to get the HEX file ready to be programmed into the microcontroller. This microcontroller has more available program memory, so the firmware has several additional features. Still there is a lot of space for additional modifications.
The schematics of the main board:
The schematics of the power board:
The photo of the prototype: