Hardware Setup

TMC5160 SPI daisy-chain topology and 7-phase motion ramp profile

This guide covers the physical connections and hardware requirements for the TMC51x0 stepper motor (TMC5130 & TMC5160) driver chip.

Pin Connections

SPI Interface Connections

MCU              TMC51x0
─────────────────────────
3.3V      ────── VDD
GND       ────── GND
SCK       ────── SCK
MOSI      ────── SDI
MISO      ────── SDO
CS        ────── CSN
EN        ────── EN (optional, can be tied high)
DIR       ────── DIR (for step/dir mode)
STEP      ────── STEP (for step/dir mode)

UART Interface Connections

MCU              TMC51x0
─────────────────────────
3.3V      ────── VDD
GND       ────── GND
TX        ────── UART_RXD
RX        ────── UART_TXD
TX_EN     ────── UART_TXEN (optional, for transceiver)

Motor Connections

TMC51x0          Stepper Motor
──────────────────────────────
1B        ────── Motor Coil B+
1A        ────── Motor Coil B-
2B        ────── Motor Coil A+
2A        ────── Motor Coil A-

Mode Configuration Pins

The TMC5160 has two critical mode configuration pins that determine the operating mode and pin functions:

Pin	Name	Pin Number	Description	Required
SPI_MODE	SPI Mode Select	22	Determines communication interface (SPI vs UART)	Yes
SD_MODE	Step/Dir Mode Select	21	Determines motion control mode (internal ramp vs external step/dir)	Yes

⚠️ CRITICAL: These pins MUST be configured correctly before power-up. They are read at startup and determine the chip’s operating mode.

Mode Configuration Table

SPI_MODE	SD_MODE	Operating Mode	Communication	Motion Control	Pin Functions
HIGH (1)	LOW (0)	SPI + Internal Ramp	SPI interface	Internal ramp generator (motion controller)	REFL_STEP/REFR_DIR: Reference switches ENCA/ENCB/ENCN: Encoder inputs DIAG0/DIAG1: Diagnostic outputs
HIGH (1)	HIGH (1)	SPI + External Step/Dir	SPI interface	External step/dir inputs	REFL_STEP/REFR_DIR: STEP/DIR inputs DCIN/DCEN/DCO: DC Step control DIAG0/DIAG1: Diagnostic outputs
LOW (0)	LOW (0)	UART Single Wire	UART interface	Internal ramp generator (motion controller)	DIAG0_SWN/DIAG1_SWP: UART I/O SDI_CFG1/SDO_CFG0: NAI/NAO addressing Other pins: Configuration inputs

Wiring Mode Configuration Pins

For SPI + Internal Ramp Generator Mode (Recommended for most applications):

SPI_MODE (pin 22) ──────> 3.3V (HIGH)
SD_MODE  (pin 21) ──────> GND  (LOW)

For SPI + External Step/Dir Mode:

SPI_MODE (pin 22) ──────> 3.3V (HIGH)
SD_MODE  (pin 21) ──────> 3.3V (HIGH)

For UART Single Wire Mode:

SPI_MODE (pin 22) ──────> GND  (LOW)
SD_MODE  (pin 21) ──────> GND  (LOW)

Important Notes:

These pins are read at startup - the chip reads their state during initialization
Must be configured before power-up or reset
Use pull-up resistors (10kΩ) to 3.3V for HIGH, or tie directly to GND for LOW
Do NOT leave these pins floating - they must be tied to a defined logic level

Software Control (Advanced):

If SPI_MODE and SD_MODE pins are connected to GPIO outputs (instead of hardwired), they can be controlled via software
Use TMC51x0PinConfig to configure spi_mode_pin and sd_mode_pin if available
Use driver.io.SetOperatingMode() to change modes programmatically
⚠️ CRITICAL: Changing mode pins requires a chip reset (power cycle or reset pin) to take effect
The mode pins are read at startup, so changes won’t be effective until the chip is reset

Pin Descriptions

Pin	Name	Description	Required
VDD	Power	3.3V power supply	Yes
GND	Ground	Ground reference	Yes
SPI_MODE	Mode Select	SPI/UART mode selection (pin 22)	Yes
SD_MODE	Mode Select	Step/Dir mode selection (pin 21)	Yes
SCK	Clock	SPI clock line	Yes (SPI)
SDI	Data In	SPI data input (MOSI)	Yes (SPI)
SDO	Data Out	SPI data output (MISO)	Yes (SPI)
CSN	Chip Select	SPI chip select (active low)	Yes (SPI)
UART_RXD	UART RX	UART receive data	Yes (UART)
UART_TXD	UART TX	UART transmit data	Yes (UART)
EN	Enable	Driver enable (active low)	Optional
DIR	Direction	Step/dir direction input	Optional
STEP	Step	Step pulse input	Optional

Power Requirements

Motor Supply Voltage: 8V to 60V DC
Logic Supply Voltage: 3.3V (VDD)
Current Consumption: ~20mA typical (logic), motor current depends on load
Power Supply: Separate motor supply recommended with proper decoupling

Bus Configuration

SPI Configuration

Mode: SPI Mode 3 (CPOL=1, CPHA=1)
Speed: Up to 4 MHz (recommended)
Bit Order: MSB first
CS Polarity: Active low

UART Configuration

Baud Rate: Typically 500000 bps (configurable)
Data Format: 8 data bits, 1 stop bit, no parity
Node Address: 0-254 (8-bit address)

Physical Layout Recommendations

Keep SPI/UART traces short (< 10cm recommended)
Use ground plane for noise reduction
Place decoupling capacitors (100nF ceramic + 10µF electrolytic) close to VDD pin
Use separate ground planes for motor power and logic if possible
Route motor power traces away from sensitive logic signals
Use twisted pair cables for motor connections

Example Wiring Diagrams

TMC5160 wiring

SPI + Internal Ramp Generator Mode (Recommended)

                    TMC5160
                    ┌─────────┐
        3.3V ───────┤ VDD     │
        GND  ───────┤ GND     │
        3.3V ───────┤ SPI_MODE│ (pin 22) - HIGH
        GND  ───────┤ SD_MODE │ (pin 21) - LOW
        SCK  ───────┤ SCK     │
        MOSI ───────┤ SDI     │
        MISO ───────┤ SDO     │
        CS   ───────┤ CSN     │
        EN   ───────┤ EN      │
                    └─────────┘

UART Single Wire Mode

                    TMC5160
                    ┌─────────┐
        3.3V ───────┤ VDD     │
        GND  ───────┤ GND     │
        GND  ───────┤ SPI_MODE│ (pin 22) - LOW
        GND  ───────┤ SD_MODE │ (pin 21) - LOW
        TX   ───────┤ UART_RXD│
        RX   ───────┤ UART_TXD│
                    └─────────┘

Next Steps

Verify connections with a multimeter
Proceed to Quick Start to test the connection
Review Platform Integration for software setup

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