Product description
Electrokit EKM028 is a relay shield compatible with Arduino UNO R3 / R4. With four relays and individual current measurement for each channel. The board is designed for controlling and monitoring appliances, machines and other applications where electrical loads need to be controlled with galvanic isolation and where current consumption needs to be measured.
The board features four Zettler AZ9371T relays with normally open contacts (SPST-NO), rated for up to 10 A at 230 VAC or 30 VDC. Each relay channel is equipped with an ACS724 current sensor that enables isolated, bidirectional current measurement within a range of ±10 A. The sensors have a sensitivity of 200 mV/A and a bandwidth of 250 kHz.
The relays are controlled via Arduino pins D8–D11, while the analog output signals from the current sensors are read via A0–A3. An LED next to each relay indicates when the relay is activated and the contact is closed.
EKM028 also features two Qwiic connectors for connecting external I2C devices, such as sensors and displays. The board is preconfigured for 5 V logic levels but can be adapted for 3.3 V systems by modifying the IOLEVEL solder jumper. Note that this modification only affects the I2C signals to the Arduino pins. The analog outputs of the current sensors can still output up to 4 V, which limits the measurable current range when used with 3.3 V systems.
The board has the same form factor as Arduino UNO R3 / R4 and is compatible with UNO-compatible development boards. EKM028 is supplied as a partially assembled kit. All SMD components are pre-installed, while the relays, screw terminals and pin headers need to be soldered in place.
Specifications:
- Manufacturer: Electrokit
- Model: EKM028
- Type: 4-channel relay shield with current measurement
- Compatibility: Arduino UNO-compatible boards
- Relays: 4 Zettler AZ9371T
- Contact configuration: Normally open (SPST-NO)
- Rated voltage (max), AC: 230 VAC
- Rated voltage (max), DC: 30 VDC
- Current (max): 10 A per relay
- Current sensors: 4 ACS724
- Measurement range: ±10 A per channel
- Measurement accuracy: ±0.2 %
- Sensitivity: 200 mV/A
- Current sensor resistance: 1.2 mΩ
- Current sensor bandwidth: 250 kHz
- Signal levels: 3.3 V / 5 V
- Current consumption: 39 mA (no relays active), 217 mA (all relays active)
- Relay control: D8, D9, D10, D11
- Current measurement: A0, A1, A2, A3
- Communication interface: I2C
- Qwiic connectors: 2
- Screw terminals: 5 mm pitch
- Wire cross-section: 0.5–2.5 mm² (AWG 20–12)
- Indication: LED for each relay
- Dimensions: 68.6 x 53.4 mm
Note: Supplied as a partially assembled kit with pre-installed SMD components. Relays, screw terminals and pin headers are included but not installed.
