A bipedal robot build from scratch

Help & Support Robot Parts
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1

Hello, I was trying to make a bipedal robot but it is getting really messy I could’nt find the right design.
My inspiration was: https://www.youtube.com/watch?v=aVJs_x2a9z4

This is a concise summary from chatgpt4o for clarification of my messy writing

A. Components:

Controller: Teensy 4.1, Hiwonder Serial Bus Servo Controller
Servos: 22x Hiwonder LX-225MG (daisy-chained by limb)
Converter: SparkFun TXB0104 Logic Level Converter
Sensors: Adafruit BNO055 IMU, HM-10 Bluetooth Module, 8x FSRs with 10kΩ resistors
Power: 2x 2S LiPo Batteries (7.4V, 5000mAh, 30C, parallel), 5V UBEC if needed

B. Power Connections

  1. LiPo Batteries → Hiwonder Servo Controller VCC+ / VCC- → Daisy-chained Servos
  2. Teensy VIN : If the Hiwonder controller doesn’t supply 5V, use a UBEC to regulate 5V from the battery.
  3. Ground: All grounds (battery, controller, Teensy, sensors) must connect.

C. Communication (w/ Logic Level Converter):

HV : 5V (from controller or UBEC)
LV : 3.3V from Teensy
Data: Teensy TX (e.g., TX1) to A1 (LV), RX1 to A2 (LV); Controller RX to B1 (HV), TX to B2 (HV)

D. Sensor Connections:

IMU (BNO055): 3.3V from Teensy, SDA/SCL to Teensy I2C pins (18/19)
Bluetooth (HM-10): 3.3V, UART to Teensy RX2/TX2
FSRs (Voltage Divider): 3.3V to FSR, 10kΩ resistor to GND; junction to analog inputs (8 total) on Teensy

Summary Diagram:

Battery → Controller + Servos
Battery → UBEC (if needed)→ Teensy VIN
Teensy ↔ Logic Level Converter ↔ Controller
Teensy ↔ IMU (I2C)
Teensy ↔ Bluetooth (UART)
FSRs to analog inputs on Teensy

There are a few problems

  1. How am I going to connect the battery to teensy and the hiwonder servo control board
  2. I couldn’t connect teensy to hiwonder servo control board, making it useless
  3. I need teensy4.1 or something similar because hiwonder would not sustain the c++ and assembly code I need to use for bipedal, 22 servo is just such a high demand
  4. My battery is huge, perhaps maybe something that is smaller but outputs the same, (it is too long)
  5. If my teensy is controlling the servo, how am I going to connect teensy to servo board and to the servo for direct control? (I am using Arduino IDE with teensy extension)

Few possible suggestions:

  1. Change teensy to something else, though hiwonder can’t sustain it either
  2. Change hiwonder to something that can manage the daisy chained servos while being able to connect to teensy(6 per limb) (4 lines cus 4 limb)
  3. I need something that can power both the teensy and a servo control board
  4. some method that can made me use teensy to connect 22 daisy chained servo while powering them in 7.4 (note teensy output 3.3V)

This is a huge mess and I really want ideas and help from you guys as my EPQ demands so much
Please help me, thank you for reading all of this!!!

2

If you want the Teensy to take over direct control of servos, avoid running all control code on the Teensy due to potential computational strain.
Instead, allow the Teensy to send commands to the servo controller in segments (e.g., for each limb separately).

3

I agree, the problem is that they are not compatible, thats why I am having my struggle, I couldnt connect them