ESP32-S3 Peripheral Test Bench

Overview

This project is an ESP32-S3 hardware validation sketch for production/lab testing. It exposes a serial command interface to run peripheral tests and returns structured PASS/FAIL responses for automation.

Core capabilities include:

• Wi-Fi connectivity
• MQTT broker connection
• Ethernet (DHCP + link)
• PCF8574 detection (PCF1, PCF2)
• Digital input/output loop checks through PCF expanders
• RGB (WS2812) LED sequence
• MAC address read
• RTC + NTP synchronization check
• USB scanner callback test
• UART2 loopback style check
• RS485 Modbus read check
• SPIFFS filesystem write/read validation
• Reset/restart validation
• Test abort during long-running checks

Serial command protocol

Command format

All incoming commands must match:

$,<COMMAND>,<VALUE>,#

Examples:

• $,WIFI,1,#
• $,MQTT,1,#
• $,ALL,1,#
• $,SUMMARY,1,#
• $,ABORT,1,#

Notes:

• <COMMAND> is case-insensitive in firmware.
• <VALUE> must be numeric (1 or 2 accepted by parser).
• Frames not matching the format are rejected.

Abort behavior

While a test is running, send:

$,ABORT,1,#

When accepted, firmware returns:

$,ABORTED,<CURRENT_TEST>,#

Supported commands

Command	Purpose
WIFI	Run Wi-Fi connect test
MQTT	Run MQTT connect/publish test (requires Wi-Fi)
ETHERNET	Run Ethernet DHCP/link test
PCF1	Detect PCF8574 at input address
PCF2	Detect PCF8574 at output address
INPUT	Validate 8 input channels via PCF1
OUTPUT	Validate 8 output channels via PCF2/PCF1 feedback
RGB	Run RGB LED color sequence
MAC	Read ESP32 MAC address
RTC	Sync NTP and verify RTC progression
SCANNER	Wait for barcode scan callback
UART2	UART2 send/receive check
RS232	Placeholder test (currently reports FAIL)
RS485	Modbus holding register read check
FILESYSTEM	SPIFFS write/read consistency test
RESET	EEPROM-armed restart test
HELP	Print list of available commands
SUMMARY	Return one-line status for all tests (0 not run, 1 pass, 2 fail)
ALL	Execute full sequence of major tests

Typical response format

Most test results follow:

$,<COMMAND>,<1|2>,<PASS|FAIL>,<DETAILS>,#

Where:

• 1 typically indicates PASS
• 2 typically indicates FAIL

Some tests emit per-channel results (for example INPUT/OUTPUT) with IN or OUT labels and pin index.

Summary response format

SUMMARY returns a single line in test-index order:

$,SUMMARY,<S1>,<S2>,...,<SN>,#

Status code meaning:

• 0 = Not executed
• 1 = PASS
• 2 = FAIL

This format is intended for production jigs and host scripts (easy to parse and fixed order).

Project file map

File	Purpose
periferal_testing.ino	Main parser, command dispatcher, abort handling, setup/loop
config.h	Pin map, Wi-Fi/MQTT/RTC settings, test constants
secrets.h	Local-only credentials (.gitignore protected)
secrets.h.example	Template for configuring local credentials
header.h	Central include aggregator
wifi_test.h	Wi-Fi test implementation
mqtt_test.h	MQTT test implementation
ethernet_test.h	Ethernet test implementation
pcf_test.h	PCF1/PCF2 scan tests
input_test.h	Input verification flow
output_test.h	Output verification flow
rgb_test.h	RGB LED test and init
mac_test.h	MAC read test
rtc_test.h	RTC/NTP test
scanner_test.h	USB scanner callback test
uart2_test.h	UART2 test
rs232_test.h	RS232 test (current placeholder behavior)
rs485_test.h	RS485/Modbus test
filesystem_test.h	SPIFFS filesystem test
reset_test.h	Reset/EEPROM test init and execution

Build & flash

This sketch is structured for Arduino ESP32 (ESP32-S3 target) and can be built/flashed using Arduino IDE or Arduino CLI with the appropriate ESP32 board package.

Important configuration note

Credentials are now separated from config.h:

• secrets.h stores local Wi-Fi/MQTT credentials (ignored by git).
• secrets.h.example is the shareable template committed to the repository.

For a new setup:

1. Copy secrets.h.example to secrets.h
2. Fill your real credentials in secrets.h
3. Build and flash