¶ Overview
REX Controller Card is an integrated board that supports various functionalities via on-board interfaces. Internal and external components can be easily integrated into the final composition of the modules of the various Bots possible to build.
Based on the picture above, installation orientation for the controller card is TOP towards the FRONT of vehicle.
As can be seen, the controller supports 4 x DC motors and 4 x Servos, in addition to Line IR sensor, external I2C devices, and an MPU6050. The on-board buzzer provides sound output. The unit can be powered by USB connection, external battery, or the built-in 2 x LiIon battery back on the bottom.
When a USB cable is plugged in, the LiIon batteries charge automatically and activity is indicated via a red LED on the board.
An ON-OFF switch on the board controls battery mode operation. On-board components and motors are only fully operational when the battery switch is in the ON position. While certain level of board functionality is possible with just the USB cable plugged in, if the switch is in the OFF position, the motors and servos will not be operating at full power.
For programming details and software support, please refer to the REX Library Guide.
¶ Component Descriptions
Below are technical descriptions of the modules and interfaces provided on the board.
¶ ESP32-WROOM
ESP32-WROOM-32 is a powerful, generic Wi-Fi + Bluetooth® + Bluetooth LE MCU module that targets a wide
variety of applications, ranging from low-power sensor networks to the most demanding tasks, such as voice
encoding, music streaming and MP3 decoding.
Data sheet
• RF certification: FCC/CERED/IC/TELEC/KCC/SRRC/NCC
• Wi-Fi certification: Wi-Fi Alliance
• Bluetooth certification: BQB
• Green certification: RoHS/REACH
• Reliablity: HTOL/HTSL/uHAST/TCT/ESD
• Wi-Fi Protocols: 802.11 b/g/n (802.11n up to 150 Mbps)
• Wi-Fi Protocols: A-MPDU and A-MSDU aggregation and 0.4 µs guard interval support
• Wi-Fi Frequency range: 2.4 GHz ~ 2.5 GHz Bluetooth Protocols: Bluetooth v4.2 BR/EDR and BLE specification
• Bluetooth - Radio: NZIF receiver with –97 dBm sensitivity
• Bluetooth - Radio: Class-1, class-2 and class-3 transmitter
• Bluetooth - Radio: AFH
• Bluetooth - Audio CVSD and SBC
• Module interfaces SD card, UART, SPI, SDIO, I2C, LED PWM, Motor PWM, I 2S, IR, pulse counter, GPIO, capacitive touch sensor, ADC, DAC, Two-Wire Automotive Interface (TWAI®, compatible with ISO11898-1)
• On-chip sensor: Hall sensor
• Integrated crystal: 40 MHz crystal
• Integrated SPI flash: 4 MB
• Operating voltage/Power supply: 3.0 V ~ 3.6 V
• Operating current: 80 Ma (Average)
• Minimum current delivered by power supply: 500 mA
• Recommended operating temperature range: – 40 °C ~ +85 °C
• Moisture sensitivity level (MSL): Level 3
¶ Buzzer
• Max. Voltage: 30V DC
• Rated current: <5mA @4000 Hz 5V
• Buzzer Type: Externally Driven
• Resonant Frequency: ~4000 Hz
¶ L9110S
L9110 4-channel motor driver is a circuit that allows you to control 4 motors through the same circuit. It is an ideal motor driver circuit, especially for use in 4wd vehicle construction. There are four L9110 motor driver ICs on the board. Four separate DC motors can be controlled in both directions with the driver card operating at input voltage between 2.5-12V.
Data Sheet
• Supply Voltage: 2.5V – 6V
• Operating Current: 800mA
• 4 input and 4 output pin
• Operating Temperature: 0, +80°C Description
¶ MPU6050
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MPU-6050 is a six-axis IMU sensor card which includes a triaxial gyro, a triaxial angual accelerometer and often used in various hobby, multicopter and robotic project. Both of the accelerometer and gyro outputs are I²C, providing 16-bit resolution out on each axis. |
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• Supply Voltage: 2.3V – 3.46V
• Operating Current: 3.9mA
• Operating Temperature: -40 , +85°C
• 9 Axis motion fusion on chip
• Serial Interfaces Supported: I2C, SPI 400kHz
• Fast mode I2C for communicating with all registers.
¶ HC-SR04
 |
The HC-SR04 ultrasonic sensor uses sonar to determine distance to an object. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package, from 2cm to 450cm or 1” to 16ft. Its operation is not affected by sunlight or black material (although acoustically soft materials like cloth can be difficult to detect). It comes complete with ultrasonic transmitter and receiver module. |
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• Power Supply: +3.3V DC
• Quiescent Current: <2mA
• Working Current: 15mA
• Effectual Angle: <15º
• Ranging Distance: 2400 cm
• Resolution: 0.3 cm
• Measuring Angle: 30 º
• Trigger Input Pulse Width: 10uS
¶ TCRT5000
 |
TCRT5000 Infrared Reflective Sensor Module is often used in line following robots, object sorting Robots because this module can sense if a surface is white or black. The measuring distance range from 1mm to 8mm and the central point is about 2.5mm. |
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Input(Emitter)
• Reverse voltage: 5V
• Forward current: 60mA
• Forward surge current: 3A
• Power dissipation: 100mW
• Junction temperature: 100°C
Output (Detector)
• Collector emitter voltage: 70V
• Emitter collector voltage: 5V
• Collector current: 100mA
• Power dissipation: 100mW
• Junction temperature: 100°C
Sensor
• Total power dissipation: 25°C
• Operation temperature range:25 to +85°C
• Storage temperature range: –25 to +100°C
• Soldering temperature: 260°C
¶ TP4056
The TP4056 is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries. Its SOP package and low external component count make the TP4056 ideally suited for portable applications. Furthermore, the TP4056 can work within USB and wall adapter.
• Input Supply Voltage(VCC): -0.3V～8V
• TEMP: -0.3V～10V
• CE: -0.3V～10V
• BAT Short-Circuit Duration: Continuous
• BAT Pin Current: 1200mA
• PROG Pin Current: 1200uA
• Maximum Junction Temperature: 145°C
• Operating Ambient Temperature Range: -40°C ～85°C Lead Temp.(Soldering, 10sec): 260°C