SD84 - 84 Channel Multifunction Servo Controller

Devantech

Overview

The SD84 is an 84 channel servo controller module. It will drive up to 84 RC servo's and maintain a 20mS refresh rate, regardless of the number of servo's used or their positions (pulse widths). It controls both the speed and position of the servo's. It's controlled by sending commands to the on-board processors over the USB bus. Each of the 84 channels can be a Digital Input, Digital Output or Servo Output. Additionally, 36 of the channels can be 10-bit Analogue inputs, making this a great animatronics controller. Drivers available for Windows, Apple, Linux and Open BSD.

SD84
Servo Channels	Up to 84
Logic Outputs	Up to 84
Logic Inputs	Up to 84
10-bit Analogue Inputs	Up to 36
Servo Refresh Rate	20mS under all conditions
Position Control	Directly programmed in uS
Speed Control	From maximum down to 20 seconds for full rotation
Control interface	USB
Servo Power	Separate terminals for voltage of your choice in groups of 8 servos
Logic Power	Direct from the USB Bus

Connections

The SD84 has 84 sets of 3-pin headers, in groups of 4 at a time. In all cases, the pin nearest the outside of the PCB is 0v Ground. The middle pin is +V power for the servo from the associated 2-pin screw terminals. The inside pin, nearest the CPU's is the signal pin.

Power

The logic circuitry on the SD84 module is powered from the USB bus and does not require any external power. You need to provide external power for the servo's or any other circuitry you want to connect to the I/O's. The servo's are powered in groups of 8 servo's. PL1 provides the power for servo's 1 to 8 on ch1 to ch8. The only exception is PL5 which powers 12 servo's ch33 to ch44 inclusive. The bar lines on the diagram above indicate which servo's are powered from which screw terminals. Each group can be powered from a different voltage, but note that the 0v grounds are all common and connected together on the PCB.

Connecting Servos

The servos are plugged directly onto the SD84, with the ground pin (black wire on a hitec servo) nearest the outside of the PCB.

Manufacturer's data

Technical Specification - link to the manufacturer