Choosing a drone ESC: PWM, DShot, telemetry and programming compatibility

Current rating and cell count are the easy half of choosing an ESC, and most bills of materials stop there. Whether the aircraft arms, filters vibration properly and can be serviced next year depends on the other half: the protocol it speaks, the telemetry it sends back and the firmware it runs.

Four layers, checked separately

An ESC has to match the aircraft on four separate counts, and it has to pass all four. The electrical layer is cell count and continuous current. The signal layer is the control protocol between autopilot and ESC. The telemetry layer is what comes back. The firmware layer decides which configuration tool can talk to it.

Sizing the propulsion (how much thrust, which motor, which propeller) is a separate question, covered in our heavy-lift propulsion guide. This article assumes you have chosen a motor and propeller and now need the controller to go between them.

One point about the electrical layer first, because the biggest single mistake happens here: don't size on the burst rating. It only says what the ESC survives briefly, at a temperature and airflow the datasheet chose. Size on continuous current in the real conditions inside your airframe. An ESC buried in a closed arm with no airflow will run hotter than the one on the datasheet.

The signal layer: PWM, OneShot and DShot

Standard PWM is the old analogue protocol: throttle is sent as a pulse width, usually 1000 to 2000 microseconds. It works with everything, and it has two drawbacks. It needs throttle calibration, and because both ends of the range are analogue timings, a wrongly set end point can cause real faults. OneShot and Multishot are the same idea, compressed in time for lower latency.

DShot is digital. Throttle is sent as a numeric value with a checksum, so a corrupted frame is detected and discarded rather than acted on, and there is no throttle calibration at all — the endpoints are defined by the protocol. It also carries a few commands, such as beeping to help find a lost aircraft, and setting motor direction in software instead of swapping two motor wires. The numbers in DShot150 to DShot1200 are signalling rates. Watch one naming trap: bidirectional DShot means telemetry coming back along the signal wire. It has nothing to do with reversing the motor, which is a separate setting.

For a new build, use digital and keep PWM for compatibility. Which of your outputs can send DShot depends on the board and firmware, though. ArduPilot documents that before version 4.5 the IOMCU-driven MAIN outputs did not support DShot at all, and that from 4.5 some F103-IOMCU boards do, behind a BRD_IO_DSHOT parameter. If your board doesn't have that parameter, you don't have the feature. Confirm the output group and firmware version before wiring the frame.

Telemetry: two different things share the name

The first is a serial telemetry wire: a separate wire from the ESC back to a UART, carrying voltage, current, capacity used, temperature and electrical RPM. It gives you current for each motor and, more usefully, the temperature of each ESC, which is how you spot the one arm running hot before it fails. It costs a wire and a spare serial port.

The second is bidirectional DShot, which sends RPM back over the same wire that carries throttle. It needs no extra wire or serial port, and modern flight stacks use it for dynamic notch filtering, which follows each motor's noise frequency as it changes instead of relying on a fixed notch. If vibration is hurting your position estimate, this is often the most valuable item on the list.

The two answer different questions: RPM feeds the filter, and serial telemetry gives you health data. Decide which one your flight stack will use, check the ESC supports that particular kind, and wire for it. "Has telemetry" on a product page doesn't say which. Support also depends on the ESC firmware and the flight firmware release together, so a combination that works on one aircraft proves nothing about another. And a configuration tool reading temperature and current on the bench is a different thing from the flight controller logging them in the air.

Firmware family decides who can service the aircraft

This is the layer most often left to chance, and you live with the result long after delivery. BLHeli-32 runs on 32-bit ESCs and is configured with BLHeliSuite32. AM32 is an open-source 32-bit firmware with its own configurator. BLHeli_S is the older 8-bit lineage and is different again. They don't mix, and a technician with the wrong tool can't even change a motor direction, let alone update firmware.

Where T-Motor names the firmware, so do we: the F55A PROII and PROIII, F60A MINI, V70A SE and Cine 55A run AM32, and the F35A, F45A and V50A run BLHeli-32. Choose on it. If an aircraft's four ESCs run AM32 and its spare runs BLHeli-32, the spare can't be configured to match.

Two practical rules follow. Keep one firmware family across an airframe, including spares. And write the firmware version next to the ESC part number in the build documents, because four ESCs on different versions behave in ways that are very hard to diagnose.

Individual, 4-in-1 or 8-in-1

An individual ESC per motor is the traditional layout: if one fails, you replace one; each arm carries its own controller; and there is more wiring. The larger fixed-wing and VTOL units in our range are built this way, and it suits long arms or currents high enough that you want the controller near the motor.

A 4-in-1 board puts four controllers on one PCB in the middle of the airframe, usually in a standard stack size: 30 × 30 mm is common, and the F60A MINI is a smaller 20 × 20 mm board. The wiring is much shorter and tidier and the whole propulsion side is one connector to the flight controller, but one failed channel means replacing all four. An 8-in-1, as in the Cine 55A, extends the same idea to an octocopter or a coaxial X8.

For a research or inspection aircraft that will be repaired in the field, individual ESCs are often worth their wiring. For a compact multirotor being built repeatedly to the same design, a 4-in-1 is faster to build and less to get wrong. Check the mounting pattern and the stack height against the frame before ordering either.

Four failures that look alike, and how to tell them apart

The motor doesn't spin and the ESC beeps a pattern. The ESC is telling you something specific, usually that it has no signal or the input voltage is out of range. Count the beeps and look them up in the firmware's own table before you change any hardware.

The motor spins on the bench and loses sync under load. This is nearly always timing or a mismatched motor, rarely current. It shows up on fast throttle changes and is the classic sign of a low-inductance motor on the wrong timing settings.

One motor runs backwards. On DShot you fix this in software. Swapping two phase wires still works, but changing the direction in firmware is easy to undo and leaves the harness alone.

The aircraft won't arm and the outputs look dead. Check the protocol first. An autopilot set to DShot on outputs that can't produce it, or a PWM ESC that was never calibrated, causes exactly this, and the ESC is fine.

For all four: change one thing at a time, with the propellers off and the aircraft held down. Most ESC fault-finding goes wrong because two things were changed between tests.

What to send with an ESC enquiry

Motor model and KV, propeller size, battery cell count and maximum voltage, expected continuous and peak current per motor, the flight controller and firmware stack, the control protocol you intend to run, whether you need serial telemetry or bidirectional DShot RPM, individual or 4-in-1 with the mounting pattern, and the ambient temperature and airflow the ESC will live in.

If you are replacing an ESC, photograph the label on the old one and send the firmware family and version with it. That is usually enough for us to find a replacement that is compatible, and not merely similar.

T-Motor ESCs by form and firmware

Current, cell count, form factor and firmware family below are as stated in our product listings. If you are adding to an existing aircraft, read the firmware column first: it is the one constraint you can't design around.

A dash means T-Motor doesn't state the figure. The fixed-wing and VTOL controllers, the AT-115A (6–14S), AT195A and the AM216A, AM116A, AM16A and AM06A series, are matched to particular T-Motor motors, so we haven't compared them on protocol. They are all in the full ESC range. Check continuous ratings, protocols and firmware versions on the datasheet for the exact part.

Parts in this guide.

Check the exact variant and revision before you order.

F55A PROIII 8S 4-in-1

55 A, 8S, AM32, 30 × 30 mm stack.

Cine 55A 8-in-1

55 A, 8S, AM32, with eight channels on one board.

F45A individual ESC

45 A, 3–6S, BLHeli-32, DShot600.

V70A SE 4-in-1

70 A, 8S, AM32.

AT-115A

6–14S controller for fixed-wing and VTOL aircraft.

All T-Motor ESCs

The full range, individual and multi-channel.

Sources.

• ESC current ratings, cell counts, form factors and firmware families from the manufacturer's published specifications.
• PWM, DShot and bidirectional DShot behaviour: the ArduPilot documentation linked below.
• ArduPilot DShot ESCs (accessed 2026-09-07)
• ArduPilot BLHeli32, AM32 and BLHeli_S ESCs (accessed 2026-09-07)
• T-Motor AM116A 3D ESC (accessed 2026-09-07)

Published 7 September 2026. Last revised 25 September 2026. Corrections to sales@vebixautomation.com.

Matching an ESC to your propulsion?

Send us your motor and KV, propeller, cell count, peak current per motor, flight controller and the protocol you plan to run. We will reply with a shortlist of parts that work together and the programming tool you will need. Ask for a quote.