Digi Drives Digital Experience in the Only Zero-Emissions-Capable Black Cab

"Digi CC6, has given us all the capabilities we had hoped for while increasing our development capabilities 15-fold. Its intelligence and usability fell perfectly in line with what we expect from our own development."

Greg Starns, Executive Director of Frazer-Nash’s
Software Development Group

For 22 years, the Frazer-Nash Group of Companies has been at the forefront of electric powertrain development. Today, all components of the powertrain are designed in-house, ensuring maximum compatibility, efficiency and functionality. Together, these companies are constantly testing and improving the range-extended electric powertrain in a variety of different applications and conditions.

As part of their mission, Frazer-Nash manufactures the Metrocab—the only zero-emissions-capable black cab currently operating in London. The purpose-built range extended electric (REEV) Metrocab taxi represents the cutting edge of green transportation design. The advanced Metrocab incorporates the latest technology for comfort, performance and safety while providing cost savings. The Metrocab has been operating on a pilot fleet basis in London since November 2014, and with high praise from London’s taxi associations, the Metrocab will also enter volume production in Coventry in 2017.

Business Problem

Digital Experience

Frazer-Nash needed a system for the display in the Metrocab—like the cab metering display—to ensure the highest quality experience for both the driver and the rider. To do this, the team needed an onboard computer to power the display in each vehicle. During development and testing, Frazer-Nash found building their own embedded solution was too costly and complex.

“We had terrible reliability and memory corruption problems. We spent ages tweaking, and we never did find the best solution. It only just about worked, and we needed it to work,” said Greg Starns, executive director of Frazer-Nash’s software development group.


“We looked at other modules and had more confidence with Digi, and we committed big time,” Starns said. “The Digi product had all of the memory timing done, which saved us 18-months of pain and work. This is why you buy a module, because all of that work, it’s already done.”


Frazer-Nash committed to Digi ConnectCore® 6 System on Module (Digi CC6), which utilizes the NXP i.MX6 Quad, to drive the Metrocab’s entire driver instrumentation and passenger displays. The module controls each Metrocab’s head unit—the taxi driver controls. The decision to utilize Digi ConnectCore6 was a change for Frazer-Nash, which traditionally develops all technologies in-house.

“Obviously, as the only piece of equipment not developed by Frazer-Nash, Digi’s solutions had to meet an incredibly high level of standards,” Starns explained. “Digi CC6, has given us all the capabilities we had hoped for while increasing our development capabilities 15-fold. Its intelligence and usability fell perfectly in line with what we expect from our own development.”

The team also moved from running Windows CE with more than 8 million lines of legacy code on the Digi ConnectCore 6 to Android.

“With our departure from in-house development, Digi’s support has been exemplary. They've got a really good module that’s very well supported. The move to Android has been great, and the overall experience with using the Digi CC6 module has been fantastic. The IMX has a comprehensive user interface for infotainment, radio, DAB radio, FM radio, a CD player and satellite navigation. It has various screens for energy flows around the vehicle. And it has detailed range displays. We've even chosen to write small applications on the new Digi CC6.”


Today, with Digi ConnectCore 6, the Metrocab provides unparalleled interactive displays that bring both safety and comfort to both driver and passenger. With the move to Android, Frazer-Nash was able to do this in the most cost effective and efficient way.

“We moved to an Android build and source code. It's turned out to be a very good thing. For what would have cost around £200,000 ($284,000 USD), I moved the development to a different environment for £1,500. The software development cycle has moved from about one project a year to around 15 a year. So it's far faster, and it's saved time and money.”

Digi CC6 enables a complete digital driver and passenger experience. It provides the driver with a multi-function touch screen display and instrument cluster with color display.

With the front of the cab being the driver’s office and home base, this couldn’t be more important.

“Where the cab driver sits—that's his office. People go into a building and that's their office, their desk, their computer. In a cab, that's the taxi driver's office. That's where he's going to spend up to 12 hours a day working and sitting,” says Sheban Siddiqi, marketing director for Frazer-Nash. “From meeting and talking with them, we understood how these guys live by every penny. That's why the data is so vital. They look at every mile; they watch their speed to make sure that they're not going too fast or too slow so they can project their earnings. We immediately did away with the analog displays because providing data on easy-to-understand digital displays became a top priority. We now have the digital display at the front, and no other taxi in the world has those.”

The taxi does this equally for the passenger. It offers passengers an interactive system at their fingertips with a color TV display with a digital infotainment system including a hands-free phone, USB charging station and access to high-speed internet. It also offers passengers unique information about their trip.

“We try to give the passenger as much information as possible as well. They can see how much CO2 they've saved by being in one of our cabs, for example. Or, they can see how much fuel is being consumed,” says Siddiqi. “Again, this is part of the philosophy of providing as much information to the passenger and the driver, which is something that we said that we needed to do from day one.”

The Frazer-Nash mission has been to create a premium powertrain product, and to make sure every facet of the Metrocab lives up to that premium level. That’s exactly what they’ve achieved today for both drivers and passengers.