Digital R/C Servo Controller with 32 Channels

The project aims to build a 32-channel digital R/C servo controller that is capable of handling multi-channel PWM signal generation.

The main component of the system is the Atmel ATmega8515L which consists of external memory bus that is used in interfacing with the memory-mapped array of 64 PWM registers inside the FPGA for better and smoother control of the whole system. This device eliminates the task of generating a large number of stable PWM control signals to drive the servos. The simple commands issued on a standard serial UART controls the dedicated serial servo controller board which handles multichannel PWM signal generation.

Some controllers may exhibit PWM jitter, timing errors, or lack of PWM synchronization between channels which results in servo tracking delays depending on the implementation. Inside an FPGA, an array of 32 parallel channels of 16-bit accuracy and 12-bit resolution PWM generation units were implemented. Initializing the FPGA registers is one of the many roles of the MCU with user-configurable servo startup positions stored in the internal EEPROM of the 8515L. The serial communication protocol is being run by the 8515L along with the updating of servo positions accordingly.

Rest of the project