An interview between Nintendo president and CEO Satoru Iwata and the hardware team responsible for the Wii MotionPlus add-on has been posted on the official Nintendo website, as the latest in the Iwata Asks series.
The long and wide-ranging interview was conducted with project leader Junji Takamoto, mechanical designer Noboru Wakitani, circuit designer Kuniaki Ito and SDK developer Keizo Ota.
The interview reveals that development of the MotionPlus began in early 2008, after Integrated Research and Development division head Genyo Takeda suggested connecting the Wii remote to a gyro sensor.
Takamoto further explains that the concept was originally suggested because "the original Wii remote could only detect movements along straight lines".
Asked by Iwata why a gyro sensor was not included originally Takamoto answered: "We actually looked into the idea of including a gyro sensor at the very start of the Wii remote's development. But the idea was rejected due to issues of both space and cost which attaching a gyro sensor would entail."
Describing the technology as "awkward" to implement, Ito explains how the accuracy of a standard gyroscope was increased fivefold, to measure 1600 degrees of movement per second. The device had to be further customised to work in two separate modes: one for slow movement and one for fast.
The Nintendo designers also found that changes in temperature, humidity and sudden impacts could radically change the device's reliability. These difficulties appear to have been the reason for the delay of the MotionPlus and bundled software Wii Sports Resort until June/July this year.
In summing up, Iwata himself states: "With Wii MotionPlus, people might think that we've just tacked on a gyro sensor, but in fact it was a product that necessitated a huge amount of trial and error, whether it was collecting Pokemotion shop displays, making steel hooks and breaking the Wii remote or simmering the components in a pressure cooker."