ProcessingBasic
CPU architecture
The instruction set and internal organization of a processor, such as Xtensa or RISC-V.
Understand the conceptContingency mode: public pages and downloads remain available; login, community, and server data may be unavailable.
TECHNICAL REFERENCE
ESP32 and industrial automation glossary
74 concepts explained from basic to advanced, with industrial context, engineering cautions and related terms.
By category
Processing6
Architecture, cores, clock and ultra-low-power coprocessors: what defines performance, compatible tools and firmware lifetime.
View termsMemory6
SRAM, PSRAM, flash and non-volatile storage: where code runs, where data stays and what survives a reset.
View termsConnectivity10
Wi-Fi, Bluetooth, mesh networks and Ethernet: the radios and interfaces that connect the ESP32 to the rest of the plant.
View termsIndustrial automation15
Protocols, signals and factory-floor buses: MQTT, Modbus, CAN, RS-485 and 4–20 mA, with what each requires in practice.
View termsPeripherals8
GPIO, converters and serial buses: the interfaces through which the ESP32 talks to sensors, actuators and displays.
View termsHardware12
Modules, boards, isolation and protection: what separates a bench DevKit from equipment that survives in the field.
View termsFirmware9
Boot, partitions, updates, real time and silicon-level security: the layer that decides whether equipment recovers by itself and whether its code can be replaced.
View termsPower8
Power consumption, sleep modes and network power: what keeps the device alive and what can bring it down.
View terms74 terms found
ProcessingIntermediate
RISC-V
An open instruction-set architecture used by newer ESP32-C, H and P families.
Understand the conceptProcessingIntermediate
Xtensa
A configurable Cadence architecture used by the classic ESP32 and the S2 and S3 families.
Understand the conceptProcessingBasic
Cores
Execution units that can process tasks concurrently.
Understand the conceptProcessingBasic
Clock
The CPU operating frequency, normally expressed in MHz.
Understand the conceptProcessingAdvanced
ULP
An ultra-low-power coprocessor that can run simple tasks while the main CPU sleeps.
Understand the conceptMemoryBasic
SRAM
Fast volatile memory used by running code, stacks, buffers and the heap.
Understand the conceptMemoryIntermediate
PSRAM
Higher-capacity external RAM with lower performance than internal SRAM.
Understand the conceptMemoryBasic
Flash
Non-volatile memory that stores the bootloader, firmware, partitions and files.
Understand the conceptMemoryBasic
ROM
Internal memory written during manufacturing with boot routines and basic functions.
Understand the conceptMemoryAdvanced
RTC Memory
A memory region powered in the RTC domain and preserved in certain sleep modes.
Understand the conceptMemoryIntermediate
NVS
ESP-IDF key-value non-volatile storage.
Understand the conceptConnectivityBasic
Wi-Fi
A wireless local network based on IEEE 802.11 standards.
Understand the conceptConnectivityBasic
BLE
Bluetooth Low Energy, a short-range technology optimized for low power consumption.
Understand the conceptConnectivityIntermediate
Bluetooth Classic
Bluetooth BR/EDR mode intended for continuous connections and traditional profiles.
Understand the conceptConnectivityIntermediate
Zigbee
A mesh networking protocol built on IEEE 802.15.4.
Understand the conceptConnectivityIntermediate
Thread
A low-power IPv6 mesh protocol based on IEEE 802.15.4.
Understand the conceptConnectivityIntermediate
Matter
An interoperable application standard running over IP, usually Wi-Fi, Ethernet or Thread.
Understand the conceptConnectivityAdvanced
IEEE 802.15.4
A low-power radio standard used by Thread and Zigbee.
Understand the conceptConnectivityBasic
Ethernet
A family of wired networking technologies standardized by IEEE 802.3.
Understand the conceptConnectivityAdvanced
Ethernet MAC
The digital controller that implements the Ethernet link layer.
Understand the conceptConnectivityAdvanced
PHY
A circuit that converts the MAC's digital data into electrical signals on the physical medium.
Understand the conceptIndustrial automationBasic
MQTT
A lightweight publish/subscribe protocol operated through a broker.
Understand the conceptIndustrial automationIntermediate
MQTT QoS
MQTT delivery guarantees: at most once, at least once or exactly once.
Understand the conceptPeripheralsBasic
GPIO
A digital pin configurable as an input or output.
Understand the conceptPeripheralsBasic
ADC
An analog-to-digital converter that turns voltage into a numeric value.
Understand the conceptPeripheralsBasic
DAC
A digital-to-analog converter that produces a voltage level from a digital value.
Understand the conceptPeripheralsBasic
PWM
Pulse-width modulation that controls the duty cycle of a digital signal.
Understand the conceptPeripheralsBasic
UART
An asynchronous serial interface with transmit and receive lines.
Understand the conceptPeripheralsBasic
SPI
A fast synchronous serial bus with a clock and individual device selection.
Understand the conceptPeripheralsBasic
I²C
A two-wire serial bus with addressing and open-drain lines.
Understand the conceptPeripheralsIntermediate
I²S
A serial interface intended for digital audio and synchronous samples.
Understand the conceptIndustrial automationIntermediate
TWAI/CAN
TWAI is the classic-CAN-compatible implementation found in certain ESP32 families.
Understand the conceptIndustrial automationIntermediate
CAN
A robust differential multi-master bus oriented around messages and arbitration.
Understand the conceptIndustrial automationBasic
RS-485
A differential electrical standard for multipoint serial communication.
Understand the conceptIndustrial automationBasic
RS-232
A point-to-point serial standard with positive and negative electrical levels.
Understand the conceptIndustrial automationBasic
Modbus RTU
A binary master/server protocol normally carried over RS-485.
Understand the conceptIndustrial automationBasic
Modbus TCP
Modbus transported over TCP/IP, normally on port 502.
Understand the conceptIndustrial automationAdvanced
OPC UA
An industrial standard for semantic modeling and secure data exchange.
Understand the conceptIndustrial automationIntermediate
4–20 mA
An analog current standard in which 4 mA represents live zero and 20 mA represents full scale.
Understand the conceptIndustrial automationIntermediate
0–10 V
An analog voltage signal standard used in drives, actuators and instrumentation.
Understand the conceptHardwareIntermediate
Galvanic isolation
Electrical separation that prevents a direct conductive path between two circuits.
Understand the conceptHardwareIntermediate
Optocoupler
A component that transfers a signal by light between electrically separated circuits.
Understand the conceptHardwareBasic
Relay
An electromechanical or electronic device that switches one circuit using another signal.
Understand the conceptHardwareBasic
Dry contact
A contact that supplies no voltage of its own and only opens or closes an external circuit.
Understand the conceptHardwareIntermediate
Open-drain
An output that pulls toward ground and needs a pull-up to produce a high level.
Understand the conceptIndustrial automationIntermediate
PNP e NPN
Sensor output topologies that source or sink current.
Understand the conceptFirmwareIntermediate
Watchdog
A timer that resets or signals the system when software stops responding.
Understand the conceptPowerBasic
Current consumption
The current demanded from the power supply, measured as an average over the cycle and as an instantaneous peak.
Understand the conceptPowerIntermediate
Current peak
A brief, high current demand concentrated in the ESP32 radio transmission moments.
Understand the conceptPowerBasic
Power supply
A circuit that converts available voltage into the voltage and current the device needs.
Understand the conceptPowerIntermediate
Decoupling
Capacitors near a load that provide local charge during fast current transients.
Understand the conceptPowerIntermediate
Light sleep
A sleep mode that suspends the CPU while preserving memory and peripherals, returning to the execution point.
Understand the conceptPowerIntermediate
Brownout
A voltage drop below the safe operating range.
Understand the conceptPowerBasic
Deep sleep
A deep sleep mode that powers down much of the chip to reduce consumption.
Understand the conceptPowerIntermediate
PoE
Power over Ethernet carries power and data over the same cable.
Understand the conceptFirmwareIntermediate
Bootloader
The initial program that validates and loads the application stored in flash.
Understand the conceptHardwareAdvanced
Strapping pins
Pins sampled during reset to define chip boot options.
Understand the conceptFirmwareIntermediate
OTA
Firmware updates over the network without physical access to the device.
Understand the conceptFirmwareAdvanced
Rollback
An automatic return to a previous firmware image when the new one fails.
Understand the conceptFirmwareAdvanced
Secure Boot
A mechanism that allows only firmware signed by a trusted key to execute.
Understand the conceptFirmwareAdvanced
Flash Encryption
Encryption of external flash contents with a key protected in the chip.
Understand the conceptFirmwareAdvanced
eFuse
One-time programmable bits used for configuration, identity and keys.
Understand the conceptFirmwareIntermediate
Partition table
A map that divides flash among applications, OTA, NVS and file systems.
Understand the conceptFirmwareIntermediate
FreeRTOS
A real-time operating system used by ESP-IDF for tasks, queues and synchronization.
Understand the conceptHardwareBasic
Pinout
A map of the functions and positions of a chip, module or board's pins.
Understand the conceptHardwareBasic
Chip × module × board
The chip is the silicon; the module adds memory, crystal and antenna; the board adds power, USB and connectors.
Understand the conceptHardwareBasic
DevKit
A development board created to prototype and evaluate a chip or module.
Understand the conceptHardwareAdvanced
EMC/EMI
Electromagnetic compatibility covers emissions and immunity to interference.
Understand the conceptHardwareIntermediate
ESD
An electrostatic discharge caused by accumulated charge transferring suddenly.
Understand the conceptHardwareIntermediate
Surge protection
Circuits that limit high-energy or high-voltage transients.
Understand the conceptIndustrial automationIntermediate
Bus termination
An impedance installed at the ends of a transmission line to reduce reflections.
Understand the conceptIndustrial automationAdvanced
RS-485 biasing
Resistors that establish a known state when no transmitter drives the bus.
Understand the conceptIndustrial automationAdvanced
Fail-safe
The principle of bringing a system to a safe state when a failure occurs.
Understand the conceptComplementary organization reference: ESPDocs / Ciência Embarcada. Original definitions oriented toward engineering.