The Gamoto is a PID closed-loop servo motor controller. It uses quadrature encoder feedback to precisely controller the position, speed, and acceleration of almost any motor. It includes an on-board H-bridge (LMD-18200) capable of driving 6A peak, or 3A continuous load. The bridge requires a minimum motor supply voltage of 12V, and a maximum of 55VDC. The base processor is a PIC16F876, which is a 28-pin PIC processor, running at 20MHz. It is paired with an LMD18200 H-bridge, which can drive 3A continuous loads, 6A peak. The motion control capabilities have been modeled after the LM629 motion control chip, and include the following:

• 32-bit registers to hold fixed point position variables (up to +/- 8 million encoder counts)
• 16-bit factors to hold Kp, Ki, and Kd constants
• 10-bit PWM resolution for motor output power/speed control, choose sign-magnitude or locked anti-phase
• High speed encoder capture (1X and 4X) logic (up to 254,000 counts/sec, or encoder pulses as fast as 2us wide). For an encoder with 1200 counts/revolution, speeds up to 12,700 rpm are possible. With 4X setting, a 500ppr encoder will show 2000 positions.
• True real-time PID control with adjustable filter constants
• Trapezoidal Trajectory Profile processing (constant accel ramp, constant velocity cruise, then constant decel rampdown)
• Storage of several trajectory profiles in flash EEPROM
• Fast PID recalculation, updating approx every 510 usec. (~2kHz)

• Step/Direction pulse inputs can be used to emulate a stepper motor driver. Each step pulse jogs the setpoint in the given direction. Great for use in light duty CNC systems. Note that the Gamoto cannot drive a stepper motor - only DC brushed motors. The step/dir inputs allow you to replace a Stepper Driver and stepper motor with a Gamoto and DC motor with encoder feedback.
• R/C (Remote Control) pulse inputs allow connecting the Gamoto to an R/C receiver. Convert a normal motor to a giant servo! Use this feature with the Analog Feedback option, and use a potentiometer instead of quad encoders for position feedback. Animatronics, robotics, automation applications.

• Serial port, at 9600, 19200 or 115200 baud. Connect to any PC by using a Type 1 RS-232 converter from SuperDroidRobots. or other similar level shifter chip, such as the Dallas/Maxim MAX232.
• RS-485-like network at 9600, 19200 or 115200 baud. Connect serial lines in parallel, and set the dip switch to an address from 0 to 7, and up to 8 Gamotos can share the serial network. No need for extra hardware. Broadcast commands supported.
• I2C protocol, with the Gamoto as a slave device. Up to 8 Gamoto boards can be on the same I2C bus, with support for broadcast commands
• Cricket Bus, a one-wire, mutlidrop bus protocol developed by MIT for use in their cricket controllers, also used by Gleason Research's HandyCricket controllers. Find out more at www.handyboard.com/cricket.

• Easily removable fuse for the motor power, with an LED indicator if it blows
• 5-position dipswitch to allow setting of baud rate, I2C address, etc.
• Jumper selectable 1X/4X encoding
• Analog Feedback option allows the use of either an analog voltage/potentiometer or a quadrature encoder for position feedback
• Encoder connector with power and ground pins, and on-board pullup resistors and signal conditioning.
• Expansion connector with four general purpose analog or digital I/O lines
• Two extra inputs dedicated to upper limit and lower limit switches, for applications where limiting is important (CNC mill, etc)
• Home switch option automatically zeros position registers and stops motor when home is sensed
• On-board flash memory to permanently store things like the PID constants, configuration, and motion trajectories.
• Two I2C connectors in parallel for easy daisy-chaining
• CricketBus connector and pigtail in parallel for easy daisy-chaining
• Separate motor power and logic power, for clean logic signals
• LEDs for Overtemp of H-bridge, fuse failure, and power indication
• Analog reading of motor current and position error available via software commands. Allows control of motor torque, sensing of obstacles / force feedback, etc.
• Programming port connector, for easy firmware updates.

• Download the comprehensive User Manual
• Get the QuickStart guide
• Read the original Seattle Robotics Society Encoder article
• Download a 1-page Product Brief

• Download the Windows MotoView 1.0.22 configuration software
• Screen shots: PID settings, Motion Profiles, Communication Logging, R/C Pulse Confguration and Viewing Registers
• Download MotoView Source Code (Visual Basic 6.0)
• Get the MotoView User Manual
• Check latest firmware revision history

• Type 1 RS-232 Converter from SuperDroidRobots
• Serial Interface Connector from Acroname. To use this you must also purchase the Extender Cable for it, and re-wire the cable to match the Gamoto pin assignment.

• Visit the on-line users group. Share code, upload photos, ask questions and solve problems.

• Java Motor Control Example - using Java to control the Gamoto
• Robo Command - a control program written in C#/.NET 2005 for a wireless, two-wheeled robot. This is a work in progress, with lots of loose ends, but it's a great starting point for using C# to control a Gamoto, because the Gamoto class and serial handling classes are fully developed.
• Sharing the Serial Port - connecting multiple Gamotos to a single serial cable.
• LabView 8.0 library and examples
• C++ Gamoto Object - code in MS Visual Studio 6.0 to control Gamoto
• Acroname BrainStem Example Code
• BasicX-24 (NetMedia controller) using I2C Sample Code and wiring diagram
• Download the Cricket Gamoto Library, and Cricket Logo test program (rename file to gxcricket.lgo)
• Using the OOPic with the Gamoto (I2C): Example Code
• Using the OOPic with the Gamoto (Serial): Example Code
• Using the Gamoto with the Basic Stamp to emulate an R/C servo (rename to pwm_to_gamoto.bs2)
• PICBasic Pro sample code (Serial protocol) gamoto_serial_pbp_example.pbp
• PICBasic Pro sample code (I2C protocol) gamoto_i2c_pbp_example.pbp