Seeed Studio’s $7 “Seeeduino V4.2” board is a full-sized Arduino Uno clone with a micro-USB host port, Uno-style expansion headers, and 3x Grove interfaces.

Arduino Pico

We’ve encounted several tiny, low-cost Arduino clones over the past couple of years including the $10 BeanDuino (20 x 11mm), $14 Arduino Pico (15 x 15mm), and $18 µduino (12 x 12mm). But in many projects smaller size is not always better, and with that in mind Seeed has respun its Seeeduino V4 into a V4.2 model with shrunken price tag — just under $7 — for what’s essentially a full-sized Arduino Uno clone with a superset of the Uno’s expansion capabilities.

Seeeduino V4.2 (left) compared to Arduino Uno
(click images to enarge)

Like the Seeeduino V4, the V4.2 is built around the same ATmega328P MCU (clocked at 16MHz) that’s used on the Arduino Uno, and offers an Uno-compatible topside expansion bus. Additionally, the Seeduino V4 and V4.2 both supplement the Uno’s I/O capabilities with connectors for interfacing with Grove modules: two on the V4, and three on the V4.2. Both boards are 115 x 78 x 25mm in size and have mounting holes that match those of the Uno.


Seeeduino V4 (left) compared to Seeduino V4.2
(click images to enarge)

All in all, the Seeeduino V4.2 redesign was said to involve:

• Adding a third Grove connector
• Improving the DC/DC circuit for better performance
• Repositioning the USB connector
• Eliminating some pads and modifying various component locations

Seeed says it achieved the V4.2’s roughly 65% price reduction “by improving our supply chain management techniques and capability, improving our agile manufacturing techniques, and making more efficent use of our factory machinery.”

Seeeduino V4.2 details
(click image to enarge)

Like its predecessor, the Seeeduino V4.2 model includes an additional set of through-hole pads beside each Arduino expansion header pin, making it easy to solder pin-headers into the bottom of the board. This is useful for plugging it into a breadboard, or for mating it with custom shields or carrier boards.

Both Seeeduino models are also compatible with the Arduino Uno bootloader, and can be programmed and powered through their micro-USB connectors. Power can also be supplied through the dedicated power jack, which supports 7 to 15V DC input.

Seeed Studio lists these differences between both Seeeduino V4x boards and the Arduino Uno:

• Use of a micro-USB port for powering and programming the board
• On-board Grove module interface connectors
• A switch for choosing between 3.3V and 5V DC power input
• Use of a DC-to-DC converter instead of an LDO (Low DropOut regulator), for enhanced efficiency
• Various improvements to circutry

The Seeeduino V4.2’s schematic and other documentation are available for download from its wiki page. Seeed Studio also touts a “Seeed Fusion” service whereby you can customize the board for a mere $25 set-up fee, with a minimum order of a single board. It’s unclear, however, how much of the design can be modified by means of this service, or to what degree the customized boards are tested prior to shipment.

 
Additional information

The Seeeduino V4.2 is currently available for $6.90 (plus shipping) from Seeed Studio’s Seeeduino V4.2 page. Additional details and documentation may be found on the board’s wiki page.