HardLabs

Irin

MGlauser·Irin·hardware/irin.kicad_pcb

Irin PCB layout, top view — open source ESP32 board by MGlauser

About the Irin PCB

Irin is an open source ESP32 PCB design by MGlauser, published on GitHub under the MIT license. It is a 2-layer board measuring 50.5 × 39.9 mm, with 12 components from 11 distinct parts.

Its main chip is the 01Space ESP32-C3-0.42LCD, from the ESP32 family. Other key parts include the MP1584EN set to 5.0V, HiLetgo ADS1115 (0x48, ADDR->GND) and DHT-22. By type, the board carries 4 ICs, 3 capacitors, 2 resistors, 1 connector, 1 fuse and 1 diode.

It belongs with the iot & wireless, power & battery and sensors designs in this gallery.

From the project

The (holy) Watcher that never sleeps. Watching over your 12v battery system and integrates with HomeAssistant.

The wakeful one: an always-on battery watcher for Home Assistant.

Irin is an always-on battery monitor that clamps onto a battery's terminals and reports voltage, state of charge (SOC), charging activity and temperature to Home Assistant over WiFi, with a tiny OLED readout on the device itself.

The prototype watches the 12V accessory battery of a 2027 Subaru Uncharted GT (an EV whose 12V battery can run down in a couple of days of parking), but nothing in it is car-specific. Change a few lines of configuration and it monitors flooded lead-acid, AGM, LiFePO4 or sodium-ion batteries in 12V…

Irin, from the project README
From the project README

Main components on the Irin

MP1584EN set to 5.0V01Space ESP32-C3-0.42LCDHiLetgo ADS1115 (0x48, ADDR->GND)DHT-22

Irin bill of materials (BOM)

12 components, 11 distinct parts.

QtyPartRefs
1
MP1584EN set to 5.0V
U1
1
01Space ESP32-C3-0.42LCD
U2
1
HiLetgo ADS1115 (0x48, ADDR->GND)
U3
1
DHT-22
U4
1
Battery terminals
J1
1
5A (Micro2 blade)
F1
1
P6KE18A (opt.)
D1
2
0.1uF
C1, C3
1
100uF/35V
C2
1
470k 1%
R1
1
100k 1%
R2

Irin design files

The KiCad project lives in the MGlauser/Irin repository on GitHub; these links point at the commit this page was built from.

Irin: common questions

What microcontroller does the Irin use?

The Irin is built around the 01Space ESP32-C3-0.42LCD, from the ESP32 family.

How big is the Irin PCB?

The Irin measures 50.5 × 39.9 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Irin?

12 components, from 11 distinct parts. The full bill of materials is listed on this page.

Where can I download the Irin design files?

From the MGlauser/Irin repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Irin design in my own project?

Yes, under the terms of its MIT license, which MGlauser chose for the repository.

Can I test firmware for the Irin without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug ESP32 firmware against it before you order a PCB.

Similar boards