DESCRIPTION Note: This TinyShield has been discontinued and replaced with the Dual Motor TinyShield (which can be stacked to support additional motors) The Motor x4 TinyShield allows you to drive four independently controlled DC brushed motors from your TinyDuino! Using four of the super miniature but very powerful 2mm x 2mm TI DRV8837 Motor Driver (H-Bridge) IC, this shield will allow for to 1.8A per channel and operate motors between 1.8 to 11V. The DRV8837 is extremely easy to use and interfaces and uses a simple PWM to control motor speed, direction, coasting and braking. The board includes a bypass capacitors, as well as heatsinking the chips to a large plane on the bottom side of the board to help with heat dissipation. An external power connection is supplied to connect up to your motor power source (like a battery), and all the connections to the motors are with standard 0.1″ spaced holes, that you can solder your motor leads into or use the supplied 0.1″ headers. The TI DRV8837 has one H-bridge driver consisting of N-channel power MOSFETs to drive a DC motor or one winding of a stepper motor, or other devices like solenoids. An internal charge pump generates needed gate-drive voltages. There are internal shutdown functions for overcurrent protection, short-circuit protection, undervoltage lockout and over temperature. The DRV8837 can supply up to 1.8 A of output current. It operates on a motor power-supply voltage from 1.8 V to 11 V, and a device power-supply voltage of 1.8 V to 7 V. There is also a extremely low power sleep mode with 120nA sleep current per channel. Note: While the DRV8837 supports 1.8A @ 11V, we highly recommend operating under 500mA @ 5V per channel unless you have some really good heat sinking in place. To learn more about the TinyDuino Platform, click here TECH SPECS To see what other TinyShields this will work with or conflict with, check out the TinyShield Compatibility Matrix TI DRV8837 H-bridge motor driver Low MOSFET On-Resistance: HS + LS 280mOhm 1.8A Max Drive Current (Recommend 500mA max) 1.8V to 11V Motor Operating Supply Voltage Range TinyDuino Power Requirements Voltage: 3.0V - 5.5V Current: 5mA (Logic only) Pins Used A3 - SLP_IN: This signal can put the motor controller into a low-power “Sleep Mode”. A logic-low “0″ will put the motor controller into sleep mode, a logic-high “1″ will put the motor controller into normal operating mode. If sleep mode is not needed, set A3 to HIGH to allow normal operation. 2 - MOT1_OUT2: This signal controls the Motor 1 Output 2 driver. A logic-low “0″ will set Output 2 to low, a logic-high “1″ will set Output 2 to high. For motor speed control, we recommend using this as the direction speed control signal, and 3 as the motor speed control signal. 3 - MOT1_OUT1: This signal controls the Motor 1 Output 1 driver. A logic-low “0″ will set Output 1 to low, a logic-high “1″ will set Output 1 to high. For motor speed control, we recommend using this as the motor speed control signal (Using a PWM signal), and 2 as the motor direction signal. 4 - MOT2_OUT2: This signal controls the Motor 2 Output 2 driver. A logic-low “0″ will set Output 2 to low, a logic-high “1″ will set Output 2 to high. For motor speed control, we recommend using this as the direction speed control signal, and 5 as the motor speed control signal. 5 - MOT2_OUT1: This signal controls the Motor 2 Output 1 driver. A logic-low “0″ will set Output 1 to low, a logic-high “1″ will set Output 1 to high. For motor speed control, we recommend using this as the motor speed control signal (Using a PWM signal), and 4 as the motor direction signal. 7 - MOT3_OUT2: This signal controls the Motor 3 Output 2 driver. A logic-low “0″ will set Output 2 to low, a logic-high “1″ will set Output 2 to high. For motor speed control, we recommend using this as the direction speed control signal, and 6 as the motor speed control signal. 6 - MOT3_OUT1: This signal controls the Motor 3 Output 1 driver. A logic-low “0″ will set Output 1 to low, a logic-high “1″ will set Output 1 to high. For motor speed control, we recommend using this as the motor speed control signal (Using a PWM signal), and 7 as the motor direction signal. 8 - MOT2_OUT2: This signal controls the Motor 4 Output 2 driver. A logic-low “0″ will set Output 2 to low, a logic-high “1″ will set Output 2 to high. For motor speed control, we recommend using this as the direction speed control signal, and 9 as the motor speed control signal. 9 - MOT2_OUT1: This signal controls the Motor 4 Output 1 driver. A logic-low “0″ will set Output 1 to low, a logic-high “1″ will set Output 1 to high. For motor speed control, we recommend using this as the motor speed control signal (Using a PWM signal), and 8 as the motor direction signal. Dimensions 20mm x 20mm (.787 inches x .787 inches) Max Height (from lower bottom TinyShield Connector to upper top TinyShield Connector): 5.11mm (0.201 inches) Weight: 1.62 grams (.06 ounces) NOTES The motors are not powered from the main TinyDuino power, there is a separate power connection labelled VM on this board that must be connected to your power supply for the motors. Even though the motor driver can support 11V at 1.8Amps, we do not recommend using more than a 5V motor at 500mA due to the small size. Be sure that your power supply is sufficient to operate these motors as well as your logic – batteries are the best. If you are running both the motors and the logic off of one power supply, we recommend avoid using a switching power supply as the transients caused can potentially damage items connected to the logic side. DOWNLOADS TI DRV8837 Product Page Datasheet Schematic Eagle Files
