INA226 current/voltage monitor
Measures bus voltage and current across a shunt and reports both over I²C. Ten lines of code buys you the ability to see a joint stalling before it burns.
The role it plays
Sensors split into proprioception — encoders, IMUs, joint torque, motor current — which tells the robot about itself, and exteroception — LiDAR, depth, force, GNSS — which tells it about the world. Build proprioception first. A robot that does not know where its own joints are cannot use a good world model anyway.
Typical use: Battery monitoring, stall detection, power budgeting.
What the numbers actually mean
The headline figure is 0 – 36 V (bus voltage), with ±20 A with 0.002 Ω shunt as the next most load-bearing number (current). At $5 in the sensors tier it sits cheap enough to prototype with and replace without regret, which is the correct way to learn a new subsystem.
How it compares
Same subsystem, closest alternatives. The primary spec column is usually the one that decides it.
| Part | Price | Primary spec | Second spec |
|---|---|---|---|
| INA226 current/voltage monitorPower telemetry | $5 | 0 – 36 V | ±20 A with 0.002 Ω shunt |
| AS5600 magnetic encoderAbsolute rotary encoder | $3 | 12-bit (4096 counts/rev) | I²C (also analog / PWM out) |
| AS5047P magnetic encoderAbsolute rotary encoder | $10 | 14-bit (16384 counts/rev) | SPI + ABI quadrature + UVW |
| CUI AMT102-VCapacitive incremental encoder | $25 | up to 2048 PPR (configurable) | Quadrature A/B/Z |
| BNO085 9-DOF IMUIMU with onboard fusion | $25 | 3-axis accel + gyro + magnetometer | Quaternion / Euler / rotation vector, plus raw |
Where it shows up
It is a component-level choice rather than a defining part of a named platform — pick it for the subsystem it serves, not to match a reference build.