Understanding ESC Protocols: DShot, OneShot, and Multishot Explained
The electronic speed controller (ESC) is the component that turns your flight controller’s commands into motor rotation. How those commands travel matters more than most pilots realize. The protocol your ESC speaks determines throttle resolution, response latency, and how well your drone handles at the limits of performance.
From PWM to Digital
The oldest ESCs used plain PWM signals, where the width of a pulse told the ESC how fast to spin the motor. PWM worked but was slow, analog, and required calibration on every ESC. Modern protocols split into two families: analog protocols like OneShot and Multishot, and digital protocols led by DShot.
Analog protocols encode throttle as a pulse width, typically between 125 and 250 microseconds. OneShot125 improved on PWM by shortening the pulse, which allowed faster update rates. Multishot pushed the pulse even shorter, down to roughly 5 to 25 microseconds, letting the flight controller update the ESC thousands of times per second. The trade-off was always the same: analog signals are susceptible to noise, drift, and the need for careful min/max throttle calibration.
Why DShot Changed Everything
DShot is a digital protocol that sends throttle values as a stream of bits rather than a pulse width. Because the value is digital, there is no calibration required and no drift over time. The ESC receives an exact throttle value, and the flight controller knows precisely what it commanded. This eliminates the calibration step that plagued analog setups and makes DShot far more robust against electrical noise.
DShot comes in several speeds — DShot150, DShot300, DShot600, and DShot1200 — with higher numbers meaning faster data rates. Most modern 4-in-1 ESCs and flight controllers support DShot600 comfortably, and it is the default choice for the vast majority of builds today. Bidirectional DShot adds telemetry back from the ESC, which powers RPM filtering and makes your PID loop dramatically more precise.
Bidirectional DShot and RPM Filtering
Bidirectional DShot lets the ESC report the actual motor RPM back to the flight controller. This data feeds RPM filtering, a technique that removes motor-related noise from the gyro signal. The result is a cleaner signal for the PID controller, which means you can run higher filters and lower latency without the risk of oscillation or mid-throttle wobble.
Enabling bidirectional DShot requires ESC firmware that supports it, typically a recent version of BLHeli32 or AM32. Once enabled, you can set up RPM filters in Betaflight and immediately notice a smoother, more locked-in feel. For most pilots, this is the single biggest free upgrade available on an existing drone.
Choosing a Protocol for Your Build
For any new build, the recommendation is simple: use DShot600 or DShot300 with bidirectional telemetry enabled. Analog protocols are legacy and only relevant when you are flying older ESCs that cannot be flashed to a modern firmware. Check your ESC’s documentation before buying — the vast majority of current-generation 4-in-1 ESCs ship with BLHeli32 or AM32 out of the box and support DShot fully.
Pairing a good ESC protocol with a quality motor and a well-tuned PID loop is what separates a drone that fights you from one that feels like an extension of your hands. Invest in a modern ESC, enable bidirectional DShot, and let the firmware do the work it was designed for.
Flashing and Updating ESC Firmware
Keeping your ESC firmware current is as important as updating the flight controller. BLHeli32 and AM32 both offer configuration tools that let you flash new versions, reverse motor direction in software, and enable bidirectional DShot. Always confirm your ESC’s exact model before flashing, and back up your current settings first. A wrong flash can brick an ESC, but a correct, up-to-date flash unlocks better performance, smoother RPM filtering, and fixes that keep your whole power train running cleanly.