Creating an RS-232 microchip for controlling the Lynxmotion AL5 type robotic arms

In this paper we shall present how we created the serial driver chip which can control the Lynxmotion AL5 type robotic arm. The hardest part was that we had to implement in FPGA the serial driver, but not the usual driver, which can communicate only an 8 bit word with the PC, but to send a whole ASCII string to another device. Most serial drivers on FPGA can respond with a certain character after they receive a command from the PC, but in this case the FPGA is slave, the PC is master and the communication is only on 8 bits, only one ASCII character. We created the serial driver in FPGA to be master, to initialize communication and to be able to send more ASCII characters, to send ASCII strings. In this case the robotic arm's servo control board is the slave and can control the robotic arm according to the SCPI (Standard Commands for Programmable Instruments) commands send from the FPGA board.