Getting on with it…

Where did the idea for Eddie come from?

Eddie was conceived from many different ideas over many years of experience. These needs included production and burn-in test equipment, controls for CNC and general automation and integrated controls in scientific instrumentation.

In each of these cases, dedicated systems could be designed and built but this comes at a cost in time and material. In some cases, PLCs have been used and we often experienced a mismatch between the usual PLC I/O and the application, and the nature of PLC languages not being entirely suited to the task. 

When the need to build test equipment arose in our new factory (for Hikari lamps), a design came to mind and the Arduino/Raspberry-Pi world was explored. Over time a realisation dawned that we could roll-our-own design that would have broad application and appeal.

We reviewed our needs. We discussed our recent experiences in other work and the conversations we had recently had about control, monitoring and IoT in general. We concluded that a modular product could be designed and would have a niche - both for our own applications and for our customers in general. How would I start to develop this idea?

What makes Eddie different from what is already available?

Eddie is modular. Card slots connected as a bus allow a combination of components. We envisage that these cards will include a range of processing options, I/O and communications ports. You can choose what cards are included and can expect the software and configuration to work together.

So you can change the CPU card in Eddie (more on this later!). You can also change the peripherals in Eddie. By peripherals we mean other cards that make I/O. You can chose from a range of communications interfaces. For example, you can have a card for driving 3 stepper motors, cards for WiFi, Bluetooth and LoRa connections and CPU cards ranging using simple eight bit devices, mid-range ARM Cortex devices right up to cards running Linux.

What basic parts does Eddie include?

The parts of Eddie include as a minimum configuration to start the system:

• The backplane,

• A power supply board which takes 24VDC power and provides internal power supplies. It may also have an ethernet switch when required. This board is built into a card cage ready to take the various card components.

• a CPU card (see next section for options in CPU cards)

Eddie is modular to allow it to be configurable for different applications. What you choose to include in the Eddie card cage makes it possible to turn Eddie into a very large number of things. Project Eddie’s mission is making Eddie configurable by adding from a range of cards and using our setup software so you can make a system suitable for your application.

Backplane

Presently we are working on our prototype with a four-slot backplane. Four slots mean four cards can be included in Eddie.

We are also considering for the future:

• A compact 2 slot system. Which reduces Eddie’s footprint and cost.

• A large 8 slot system. Which makes Eddie suitable for complex applications.

We aren’t developing these options just now - but they are part of our planning.

How much choice does Eddie offer in computing capacity?

Some examples of Eddie CPU configurations:

You can choose which of our CPU cards is included in Eddie (50mm x 100mm CPU cards will be developed). We take the CPU chip and integrate it into a circuit board which works with our backplane and the rest of the Eddie system. In the simplest concept you have 1 CPU on the backplane, but you can alternatively have 2 CPU’s operating simultaneously on the backplane.

The CPU chips we’re considering putting onto Board Owl CPU cards include: 

• Leonardo Arduino (the simplest modern Arduino you can buy), 

• SAMX51 which is an ARM processor, lots of power, enough to talk on wired ethernet and process signals quickly.

• Raspberry Pi based. To allow full operating system functionality.

Our planning presently indicates that a 120MHz ATSAMx51 CPU (ARM Cortex M4) will give us best initial impact. This card would have:

• Ethernet

• Optional RFM95 LoRA radio

• Optional CAN bus

• USB-C interface

• SD Card slot

• Eight I/O ports. Each port programmable for:

• V in, out

• I in, out

• Digital in/out

• Drives both backplane SPI (Serial Peripheral Interface) channels

• Drives both backplane I2C (Inter Integrated Circuit) channels

How much choice does Eddie offer in I/O capacity?

If you need more I/O than is in the CPU card you select, then you can add just an I/O card or a set of I/O cards to Eddie. 

Some I/O cards will be dumb and some will by smart. By this we mean some I/O cards will have a dedicated CPU of their own on them so they can do things quickly with the I/O (Generally you don’t need to program these CPUs - even though it is possible). An example of a smart I/O card would be a card for driving motors, so you might want your main CPU to issue commands to move the motor in a specific profile. The task is handled by the intelligence in the card. 

(The motor controllers we’re specifying might have a servo motor interfaces and a stepper motor interfaces. They could be for lab or semi-industrial applications. We expect it to be feasible to load up software called GRBL onto the stepper card CPU to talk to it using G-code to run a pick and place machine or 3D printer. It’s like a smart PLC system but a wider range of programming options)

We also want Eddie to have lots of communications capability. We are prototyping interfaces for 10/100 Ethernet, CAN, Wireless LAN (as station or AP), Bluetooth/Bluetooth-LE or LoRa/LoRaWAN for long range wireless connections.

This blog entry was extracted from our first newsletter back in July 2025. We are slowly moving to blog news instead of sending newsletters.