Coral M.2 Accelerator with Dual Edge TPU takes advantage of m.2 E-key slot to implement two TPUs on a single tiny card. The trick is: it requires two PCIe x1 buses (as per m.2 specification), while most of the systems implement only one PCIe bus. This leads to the fact that only one TPU core is visible on most of the systems, no matter what adapters are being used.

Solution is to use PCIe packet switching to enable both cores on a single PCIe x1 bus. This allows:
- enable two cores on m.2 E key slot with single PCIe bus
- use Dual Edge TPU on m.2 B+M key slot
- use Dual Edge TPU on desktop PCIe x1 slot with dirt cheap PCIe-m.2 B+M adapters

Current status is: production/sales
PCIe version: https://www.makerfabs.com/dual-edge-tpu-adapter.html
m,2 B+M version: https://www.makerfabs.com/dual-edge-tpu-adapter-m2-2280-b-m-key.html