Article: NuttX RTOS for PinePhone: USB with Enhanced Host Controller Interface

[lupyuen]

Weeks ago we talked about porting Apache NuttX RTOS (Real-Time Operating System) to PinePhone, and how we might turn it into a Feature Phone.

But to make phone calls and send text messages, we need to control the LTE Modem over USB. Thus today we’ll build a USB Driver for NuttX on PinePhone…

1. What’s USB Enhanced Host Controller Interface (EHCI)

2. Why it’s simpler than USB On-The-Go (OTG)

3. How we ported the USB EHCI Driver from NuttX to PinePhone

4. Handling USB Clocks and USB Resets on PinePhone (with tips from U-Boot Bootloader)

5. And the NuttX EHCI Driver boots OK on PinePhone!

NuttX RTOS for PinePhone: Simpler USB with EHCI (Enhanced Host Controller Interface)

[moodroid]

Thanks so much for all your hard work on this, and really enjoying all your posts.

Really hoping you'll be the first person to get the modem working 100%. Could be a game changer!

[lupyuen]

Thank you so much for reading :-)