splitgrade-controller-sensecap

Primary-tier SenseCAP controller for an open-source splitgrade darkroom: touchscreen UI, optional light-sensor assist, and ESP-NOW control of the shared enlarger LED head.

License: MIT — Copyright © 2026 Dragan Bojovic.

Companion / budget tier (phone over BLE): splitgrade-controller-android

Shared enlarger-head firmware: darkroom-enlarger-head

What this is

Three PlatformIO projects in one repo (open each subfolder as the PlatformIO root, not this parent folder):

Folder	Board	Role
darkroom-sender/	SenseCAP Indicator D1 (ESP32-S3 + touchscreen)	Operator UI, exposure state machine, dose calibration
darkroom-rp2040/	SenseCAP Indicator RP2040	Sensor bridge (TSL2591 / AS7343) over UART to the sender — see examples/darkroom_bridge/
darkroom-receiver/	Second SenseCAP (optional)	Bench stand-in head (full-screen colour, no LEDs) for ESP-NOW testing without a panel

The real LED head is not in this repo — flash darkroom-enlarger-head onto a XIAO ESP32-S3.

protocol.h in the sender (and copies in receiver / head firmware) is the ESP-NOW wire format. Sender is the source of truth — if it changes, re-copy into the head firmware.

Beta scope

For: hobbyists with a SenseCAP Indicator who want wireless splitgrade control and optional sensor-assisted starting exposures.

Includes: ESP-NOW head control, hard/soft workflow, calibration UI, RP2040 sensor bridge sketch, German/English user docs under docs/.

Not this repo: Android BLE app, panel Gerbers, Play Store / SenseCAP factory firmware. Sensor assist is optional — the head works with manual times alone.

Requirements

• PlatformIO Core
• SenseCAP Indicator D1 (sender); RP2040 co-processor for sensors
• Enlarger head running darkroom-enlarger-head
• Optional second SenseCAP as darkroom-receiver for bench tests

Build / flash

cd darkroom-sender
pio run
pio run -t upload
pio device monitor

Set upload_port / monitor_port in each platformio.ini to your serial device. The RP2040 bridge uses a UF2 flash flow (BOOTSEL) — see docs/TECHNICAL_CONCEPT.md § Build & flash notes.

Docs

File	Contents
docs/TECHNICAL_CONCEPT.md	Architecture, protocol, calibration math
docs/USER_GUIDE.md / docs/BEDIENUNGSANLEITUNG_DE.md	Operator guide EN / DE
docs/HARDWARE_BRINGUP_NOTES.md	Bring-up notes
docs/CROSSOVER_EXPLAINED_DE.md	Cross-channel correction (DE)

Status

Primary-tier stack developed and exercised on real SenseCAP hardware; ESP-NOW path confirmed against the real LED enlarger head. Pair with the published head firmware and (optionally) the Android budget controller.