FPGA and Pi in Space: Lattice Certus NX Space Dev Board

Adam Taylor's Adiuvo Engineering has released a new FPGA development board targeted specifically for the demanding requirements of space applications. As mentioned on his blog, Adiuvo Engineering quite frequently does design and development in the space industry, so naturally the announcement of a new FPGA for space applications caught his attention.

The Lattice Certus NX Space Dev Board from Adiuvo Engineering is powered by a Certus™-NX LFD2NX-40. This Lattice Semiconductor FPGA (in collaboration with CAES) is equipped with 40K LUTs, 2.5 Mbit of BRAM, 56 DSP (18x18), 2 ADC and inbuilt 32KHz and 450 MHz Oscillators. They are 28nm devices that feature temperature-resistant tin-lead (SnPb) terminations using a radiation-tolerant, fully-depleted silicon-on-insulator (FD-SOI) manufacturing process.

This is the fancy way of saying these FPGAs are specially fabricated to be able to withstand the harsh environment of space without error or issue. Because while one's natural assumption is to think that space is a vast realm of emptiness, that's not actually the case. Space is actually full of radiation, as outlined by this great article on NASA's website explaining the nuances of space radiation.

Space radiation is ionizing radiation (high-energy). This poses a threat to an FPGA in that when a high-energy ion collides with it, the ions can knock the electrons of the substrate of the programmable logic around thus causing the logic gates to no longer function as expected.

This misalignment of the electronics in the substrate can either be temporary or permanent. In the event of the former, this causes an error referred to as a Single Event Upset or Single Event Effect. As the name implies, this means that HDL firmware will have a certain number of clocks where the data is erroneous. There is also the chance the electrons of the substrate are permanently misaligned and the FPGA is damaged.

All this to say: it's very important it is very important to use an FPGA "built" for space if that's where it's going. And as a personal observation, the Lattice Certus NX Space Dev Board fills a very open gap in the market for rad-tolerant FPGA development boards. While one can find options for rad-tolerant FPGAs, a development board that one can start developing an application on out-of-the-box is an otherwise hard find.

In conjunction with the rad-tolerant FPGA, the Certus NX Space Dev Board hosts peripherals commonly used for the command, control, instrumentation, and communication interfaces utilized in space. The 10 Pmod connectors provide a method to connect off-the-shelf options for common space interfaces such as CAN, RS485, UART, SpaceWire, etc. as well as peripherals such as monitoring cameras, sensors, and ADCs/DACs.

There is one more peripheral on the Certus NX Space Dev Board that really sets it apart from anything else on the market, and that is the Raspberry Pi Pico that is connected to the both the FPGA and the Lattice In-System Programmable Hardware Manager. As Taylor has demonstrated in his blog, the Raspberry Pi Pico is very handy for emulating systems, sensors, and communication interfaces during the system integration phase of an FPGA project.

On the Certus NX Space Dev Board specifically with the way it is connected, the RPi Pico can access/report telemetry on the supply rails to the FPGA so the FPGA's current draw can be characterized then reported to a monitoring computer. It can also be used to simulate satellite platforms and equipment interfaces so otherwise hard to replicate edge cases can be simulated in a state machine.

As with all of the great things Taylor does, a full user manual and basic example code was released with the Certus NX Space Dev Board along with a tutorial for its hardware and software.

In conclusion, I feel the need to touch on how important it is to have a development board for space applications like this that gives engineers the fine-tuned flexibility to hone in their design before investing the time and effort of laying out a custom PCB. The Certus NX Space Dev Board is currently available, so if you're interested email: space@adiuvoengineering.com