The SPEEEduino version 1.0 is the first prototype production batch of the SPEEEduino, with a total production volume of 80, for initial prototyping and testing of basic functionalities.

Renderings of the SPEEEduino v1.0, courtesy of Autodesk's circuit.io online service.

Issues

Short version

• Diode D1 affects serial communication
• Using a jumper for the FLASH header is unwieldy, as the user may lose the jumper
• D7's voltage divider pulls low the pin unintentionally, which means that D7 cannot be used as a normal pin
• ESP8266 module is not stable when used with most power supplies

However, the SPEEEduino v1.0 can still function identically to a normal Arduino Uno, sans pin D7. The SPEEEduino v1.1 is designed to address all of these issues, and the power supply is radically redesigned.

Long version

Testing results revealed that the initial batch had issues with serial communication, namely, the diode D1 is not supposed to be designed this way, as it impedes the serial signal too much (possible distortion of waveform and too much reduction in voltage). The issue can be remedied by soldering a jumper wire across D1.

Furthermore, the header labelled FLASH must be soldered on and a jumper inserted for the ESP8266 module to boot from its internal flash memory, or in other words, to boot up normally.

When the ESP8266-01 module is not plugged in, pin D7 of the Arduino is pulled low. While the pull-down resistance is only around 30kΩ, this may interfere with the operation of certain devices if you intend on using that pin.

The most crucial design flaw, which must be rectified by a near complete redesign of the board, is the power delivery system to the ESP8266-01 module. Our in-lab testing showed that the ESP8266-01 module became unstable at times when it required an elevated amount of power (such as creating an access point, or actively transmitting data).

However, the good news is that the SPEEEduino v1.0 can otherwise still function identically to a standard Arduino, sans pin D7. If the user requires more digital pins, they can consider the pins equipped with ADC functionality (A0 to A5) to be reprogrammed as general purpose digital I/O pins.