PCB

Flexbot PCBs

Teensy board

Figure 1. Plug names and pin allocation for Teensy board.

• IMU0, on-board, SCL0, pin 18-19, AD0=NC, Knee.
• IMU1, SCL1, pin 37_38-19, AD0=HIGH, Thigh (upper leg).
• IMU2, SCL1, pin 37_38-19, AD0=NC, Shin (lower leg).
• IMU3, SCL2, pin 3_4, AD0 = HIGH, Foot.
• IMU4, SCL2, pin 3_4, AD0 = NC, Hip.

Actuators

Steering

• 1: 12V,
• 2: PWM pin 5 - moved to pin 29 (timer FTM2),
• 3:pot pin 23 (A9),
• 4: GND

Actuator 1 - upper leg

motor

• 1: direction pin 24
• 2: PWM pin 2 (timer FMT3)
• 3: GND

encoder

• 1: 5V
• 2: A pin 39
• 3: B pin 30 - moved from A21 DAC0)
• 4: GND

Actuator 2 - lower leg

Motor

• 1: direction pin 25
• 2: PWM pin 22 (timer FMT0)
• 3: GND

encoder

• 1: 5V
• 2: A pin 5 (moved from A22/DAC1)
• 3: B pin 36
• 4: GND

Wheel

motor driver

• 1: 5V - NB! provided by driver should not be connected
• 2: PWM pin 21 (timer FTM0) (S1) (RC mode 100 Hz)
• 3: pin 26 (S2) - not used
• 4: GND - NB! connected to motor power GND (probably OK to connect)

encoder

• 1: 5V
• 2: A pin 35
• 3: B pin 34
• 4: GND

current

• 1:

Cables in leg

Figure 2. Overview of cables in one leg with some wire details. The connection to robot base platform is 24V (10A) and USB only. Steering servo should be in RC servo interface mode

Controller block diagram

Figure 3. Functional blockdiagram og Teensy controller board. Not all blocks and MAV messages are implemented yet.

Teensy board and schematic

Figure 4. Layout of PCB (designed in Eagle).

Figure 5. PCB schematic - click on image to get better view.

Figure 6. Needed patches. PWM for steering servo in RC mode now moved to timer FMT3 on pin 29 (old connection to pin 5 must be cut). Actuator 1 encoder A also connected to pin 5 (for interrupt), and actuator 2 encoder B also connected to (free) pin 30 - also for interrupt. The last 2 maintains connection to DAC pins and pull-up resistors.