Arduino library for controlling MKS SERVO42D/57D closed‑loop stepper drivers over CAN.
- Full support for all official MKS CAN commands (position, speed, homing, I/O, parameters, protection, emergency stop, etc.)
- Automatic CRC calculation and frame encoding
- Pluggable CAN‑bus backend via the
ICanBusinterface- TWAI on ESP32 (built‑in)
- SPI/MCP2515 support (tested)
- Human‑friendly response decoding with
pollResponses()
- Clone into your Arduino libraries folder if not available in Library Manager:
cd ~/Arduino/libraries git clone https://github.com/YourUser/MKSServoCAN.git
- For ESP32/TWAI: ensure your ESP32 board definitions are installed.
- For MCP2515: install the MCP_CAN library (e.g. via Library Manager) and include
<SPI.h>.
#include <Arduino.h>
#include <TwaiCan.h>
#include <MKSServoCAN.h>
#define MOTOR_ID 1
TwaiCan bus(GPIO_NUM_27, GPIO_NUM_26);
void setup() {
Serial.begin(115200);
while (!Serial);
if (!MKSServoCAN::begin(&bus)) {
Serial.println("CAN init failed");
while (1);
}
MKSServoCAN::goHome(MOTOR_ID);
}
void loop() {
MKSServoCAN::pollResponses();
}#include <Arduino.h>
#include <McpCan.h>
#include <MKSServoCAN.h>
#define MOTOR_ID 1
#define MCP_MISO 19
#define MCP_MOSI 23
#define MCP_SCLK 18
#define MCP_CS 5
#define MCP_INT 17
McpCan bus(
MCP_MISO,
MCP_MOSI,
MCP_SCLK,
MCP_CS,
MCP_INT,
CAN_500KBPS
);
void setup() {
Serial.begin(115200);
while (!Serial);
if (!MKSServoCAN::begin(&bus)) {
Serial.println("CAN init failed");
while (1);
}
MKSServoCAN::goHome(MOTOR_ID);
}
void loop() {
MKSServoCAN::pollResponses();
}All functions take a device ID (1–2047).
| Function | Code | Description |
|---|---|---|
readEncoderCarry(id) |
0x30 | 32‑bit carry + 14‑bit current value |
readEncoderAdd(id) |
0x31 | 48‑bit cumulative encoder count |
readSpeed(id) |
0x32 | Real‑time RPM |
readPulses(id) |
0x33 | 32‑bit pulse count |
readIOstatus(id) |
0x34 | 8‑bit I/O port status |
readRawEncoder(id) |
0x35 | Raw 48‑bit encoder count |
readAngleError(id) |
0x39 | Angle error (ticks) |
readEnablePin(id) |
0x3A | EN‑pin state |
readZeroStatus(id) |
0x3B | Zero‑on‑power return status |
releaseProtection(id) |
0x3D | Release locked‑rotor protection |
readProtectState(id) |
0x3E | Protection active (yes/no) |
| Function | Code | Description |
|---|---|---|
calibrate(id) |
0x80 | Encoder calibration |
setWorkMode(id, mode) |
0x82 | 0=CR_OPEN…5=SR_vFOC |
setCurrent(id, ma) |
0x83 | Working current (mA) |
setMicrostep(id, steps) |
0x84 | Micro‑step subdivision |
setEnActive(id, lvl) |
0x85 | EN‑pin active level |
setDirection(id, dir) |
0x86 | 0=CW,1=CCW |
setAutoSleep(id, enable) |
0x87 | Auto turn‑off OLED |
setProtect(id, enable) |
0x88 | Locked‑rotor protection |
setInterpolator(id, enable) |
0x89 | Subdivision interpolation |
setHoldCurrent(id, pct) |
0x9B | Holding current percentage |
setCanRate(id, rate) |
0x8A | CAN bit rate (0=125k…3=1M) |
setCanId(id, newId) |
0x8B | Change device CAN ID |
setCanResponse(id, resp, act) |
0x8C | Slave respond & active flags |
setGroupId(id, gid) |
0x8D | Group address |
setKeylock(id, lock) |
0x8F | Front‑panel key lock/unlock |
| Function | Code | Description |
|---|---|---|
setHomeParams(id, trig, dir, spd, lim, mode) |
0x90 | Configure homing |
goHome(id) |
0x91 | Execute homing |
setZeroPoint(id) |
0x92 | Define current position as zero |
setNoLimitReturn(id, angle, ma) |
0x94 | “No‑limit” return parameters |
setLimitRemap(id, enable) |
0x9E | Remap limit switches |
| Function | Code | Description |
|---|---|---|
setZeroMode(id, mode, en, speed, dir) |
0x9A | Zero on power‑up behaviour |
restoreDefaults(id) |
0x3F | Reset to factory parameters |
restart(id) |
0x41 | Restart firmware |
setEnTrigger(id, eTrig, pProt, tim, err) |
0x9D | EN‑trigger zero & pos‑error prot. |
readSystemParam(id, code) |
0x00+code | Read arbitrary system parameter |
| Function | Code | Description |
|---|---|---|
queryStatus(id) |
0xF1 | Motor status |
enableMotor(id, enable) |
0xF3 | Enable/disable motor |
emergencyStop(id) |
0xF7 | Emergency stop |
speedMode(id, speed, accel, ccw) |
0xF6 | Constant speed mode |
speedModeStop(id) |
0xF6 (acc=0) | Stop speed mode |
speedState(id, save) |
0xFF | Save/clear speed parameters |
posRelative(id, pulses, speed, accel, ccw) |
0xFD | Relative‑pulse move |
posRelativeStop(id) |
0xFD (acc=0) | Stop relative move |
posAbsolute(id, axis, speed, accel) |
0xFE | Absolute‑position move |
posAbsoluteStop(id) |
0xFE (acc=0) | Stop absolute move |
posAxis(id, relAxis, speed, accel) |
0xF4 | Relative‑axis move |
posAxisStop(id) |
0xF4 (acc=0) | Stop axis move |
- ESP32 WROOM with built‑in TWAI peripheral
- Waveshare SN65HVD230 CAN transceiver
- MCP2515 SPI‑to‑CAN bridge (3.3 V logic + 5 V VCC)
- MKS SERVO42D/57D driver modules
- Support for A/B/C/D/E variants of the SERVO42/57 drivers
- Additional SPI‑based CAN backends (e.g. on AVR, STM32, Arduino Uno)
- Linux SBC support (Raspberry Pi, Jetson)
- Expanded MCU compatibility (Due, Teensy, etc.)
- Collaborative hardware compatibility matrix — please share your test results!
- Official MKS SERVO42C repo: https://github.com/makerbase-motor/MKS-SERVO42C
- Official MKS SERVO57D repo: https://github.com/makerbase-motor/MKS-SERVO57D
Pull requests and issues welcome. When submitting, please include your:
- MCU type
- CAN transceiver model
- Hardware wiring (pin assignments)
- Test outcome (working/non‑working)
Creative Commons Attribution‑NonCommercial 4.0 International
(CC BY‑NC 4.0)
Anyone may copy, share, modify, and distribute this code with attribution to Will Hickmott.
Commercial use (selling, bundling in a paid product, etc.) is forbidden.