It's an even smaller board that fits inside a USB port. It's good for making a Raspberry Pi pocket-sized. I use it as a WiFi keyboard for typing Chinese. It's much easier to use handwriting recognition on my phone for characters that I don't know.
To get the EspUSB built, I had to download the KiCAD designs, generate Gerber files, guess the BOM, email back and forth with PCBWay, pay 70 EUR for 3 units, and have a stable address for them to ship to. And I still had to solder on serial wires, boot into Ubuntu, build and flash the firmware myself. The whole process took a couple of years. I'm starting that process (guessing the BOM) for the HDMI-PI now, but discovered that I also need to design an adaptor from MIPI-iPhone LCD connector so it will probably be another year or two before I finally get it built.
After the long process of having custom hardware built, I thought I'd write about it and maybe get some more built and sell them online. But I was scared away by FCC regulations: I could be sued for $100,000 or more if I sell a WiFi device that isn't certified, and it costs $10,000 to get the certification. So I gave up on trying to make it easier. Hardware is hard.
https://github.com/cnlohr/espusb
It's an even smaller board that fits inside a USB port. It's good for making a Raspberry Pi pocket-sized. I use it as a WiFi keyboard for typing Chinese. It's much easier to use handwriting recognition on my phone for characters that I don't know.
https://www.youtube.com/watch?v=FPBzOaLbWhM
To get the EspUSB built, I had to download the KiCAD designs, generate Gerber files, guess the BOM, email back and forth with PCBWay, pay 70 EUR for 3 units, and have a stable address for them to ship to. And I still had to solder on serial wires, boot into Ubuntu, build and flash the firmware myself. The whole process took a couple of years. I'm starting that process (guessing the BOM) for the HDMI-PI now, but discovered that I also need to design an adaptor from MIPI-iPhone LCD connector so it will probably be another year or two before I finally get it built.
After the long process of having custom hardware built, I thought I'd write about it and maybe get some more built and sell them online. But I was scared away by FCC regulations: I could be sued for $100,000 or more if I sell a WiFi device that isn't certified, and it costs $10,000 to get the certification. So I gave up on trying to make it easier. Hardware is hard.