R/C Pulse to PWM Converter with 2 Channels

Overview

Two easily formed R/C pulse signals are converted into a PWM signal suitable for driving small motors as it uses an AVR chip and software.

Details

For the chip that uses a SN754410 chip as the output driver, a reference design board has been created. This design can drive any H-bridge motor driver chip or circuit but within the limits of the converter chip output drive. For the standard L293D, the TI chip is an improved drop-in replacement. A 1 Amp output capacity per channel with a maximum motor supply voltage of 35V is contained in the TI chip.

An Atmel AT90S1200 chip with a 16MHz clock is used to run the software. The chip has missing pulse detection that kills the output if R/C signal fails. It also has output disable input for each channel, forward/reverse & enable outputs for each channel, in-circuit programmable via an Atmel STK200 dongle & ISP software, and with jumper selectable options.

There are two versions that are included in the software consisting of straight and mixed mode. Straight mode just does two independent channel conversions while mixed mode is intended for single joystick applications.