Understanding ESC Protocols: DShot, PWM and Multishot
The electronic speed controller, or ESC, is the unsung hero of every FPV quadcopter. It translates the flight controller’s commands into the precisely timed electrical pulses that spin each motor. But how the flight controller talks to the ESC matters just as much as the hardware itself. This article explains the ESC protocols — PWM, OneShot, Multishot, and DShot — and why the protocol you choose affects responsiveness and reliability.
What an ESC Actually Does
An ESC receives a throttle signal from the flight controller and converts it into three-phase alternating current to drive the brushless motor. The rate and precision of that signal determine how quickly and smoothly the motor responds. Older protocols sent a simple pulse-width signal updated only a few hundred times per second, while modern digital protocols communicate far faster and with fewer errors.
Every motor command travels from the flight controller to the ESC over a signal wire. The protocol defines both the speed of that signal and how it encodes the throttle value. A faster, more accurate protocol lets the flight controller correct the motor speed more often, which translates directly into smoother, more locked-in flight.
From PWM to Multishot: The Analog Era
The original PWM protocol encodes throttle as the width of a pulse, refreshed around 400 times per second. That sounds fast, but for a racing quad it introduces noticeable latency and limits how quickly the flight controller can stabilize the aircraft. OneShot125 improved on PWM by shortening the pulse and refreshing roughly eight times faster.
Multishot pushed analog signaling further, updating up to around 32,000 times per second. Faster refresh reduced latency and let high-performance flight controllers respond more precisely. The analog protocols all share one weakness, however: they encode throttle as a pulse width that can drift with electrical noise, and they require the ESC to be calibrated to the flight controller.
DShot: The Digital Standard
DShot changed the game by transmitting throttle as a digital value instead of an analog pulse. Because the signal is digital, it is immune to the analog noise and calibration drift that plagued earlier protocols. DShot also carries a checksum, so the ESC can detect and reject corrupted frames rather than acting on a glitched throttle value.
DShot comes in several speeds — DShot300, DShot600, and DShot1200 — each refreshing faster than the last. DShot600 is the most common choice for modern builds, offering an excellent balance of speed and reliability. DShot1200 is faster still but requires cleaner wiring to remain stable. Most pilots should simply select DShot600 and enable bidirectional DShot if their hardware supports it.
Bidirectional DShot and RPM Filtering
One of the biggest modern advancements is bidirectional DShot, which lets the ESC report the motor’s actual RPM back to the flight controller. The flight controller uses that real-time data to set accurate RPM filters, removing motor noise from the gyro signal far more precisely than the older static filtering approach.
Enabling bidirectional DShot requires ESCs with the appropriate firmware and a flight controller that supports it. Once configured, most pilots notice a cleaner gyro signal and the ability to run lower filter levels, which sharpens the quad’s responsiveness. It is one of the most worthwhile tuning upgrades available today and requires no new hardware on most modern builds.
Choosing ESCs and Firmware
Nearly all modern ESCs support DShot out of the box. When shopping, look for ESCs rated above your motors’ peak current, and check whether they run BLHeli_S, BLHeli_32, or AM32 firmware — each supports DShot and configurable motor timing. Pairing a quality ESC with DShot600 gives you precise throttle control, smooth idle behavior, and the digital reliability that makes modern FPV drones feel so locked in.