I made a thing! Let me in the cool kidz club!
As I wrote before I am exploring the trail of jailbreaking my Kindle and the only option available to me is the serial Jailbreak.
As I don’t have a USB serial adapter that can talk 1.8V I’m looking at alternatives. One is a level shifter, an interface can speak both 5V and 1.8V digital signals. To make sure I can have the electrical connection from the kindle to this component I am investigating using pogo pins, a very little hollow tube with spring loaded electrical contacts.
To make sure that we can make the contacts I created a PCB with 4 aligned holes spaced 0.1mm, I will solder the pogo pins in place and check that the pins touch the pads and are correctly spaced.
Once the alignment is done the rest of the work is in making sure that the contacts are actually useful for UART communication, I have a USB serial adapter rated for 5V so I will use it with these adapter PCB to test connection on another board runing at 5V.
The next step is then doing two versions of my UART adapter, one with a logic level shifter and one with a dedicated component that can do UART to USB at 1.8V. Why this? Why not one level shifter adapter as stated before?
Turns out that PCB assembly can get expensive, more components means more money to pay for both assembly and sourcing. I am a guy alone so my costs are not gonna be out of the roof but I might be interested in distributing more than one of this board. The more people I can get into Kindle development the more interesting it becomes, keeping costs down and reduced component count can be a winner in this context.
Expect some more news about this as I go!