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themasterandmat · 01-09-2021, 05:59 AM

Sad news for those playing at home.

I opened up my KT4, hooked up a modified USB to Serial adapter to allow 1.8V comms, and tried to talk to it at 115200 with no joy. I took some pictures, but I'm too new to attach files.

Basically I soldered wires to the port that looks like a serial port in this thread: https://www.mobileread.com/forums/sh...d.php?t=267541
It's at the bottom right corner of the KT4

I tried swapping the TX and RX lines, that didn't work either. There was no communication at all, I tried disconnecting and reconnecting the battery while it was all hooked up to see if I could get something when it first started up. Also nothing.

Reading that thread Dave suggested, and a bit more digging, I might have to wire directly to the processor, but it's under some EMI shielding, so I'll have to get a heat gun to it or something.

There's also a chance that my voltage step down converter isn't connected correctly, so it's back to the drawing board. I do have a cheap oscilliscope, I'm just waiting on a replacement probe for it, so I'll try again when that arrives and see if I can see any blips on either of the lines

01-09-2021, 05:59 AM	#7
themasterandmat Junior Member Posts: 4 Karma: 10 Join Date: Dec 2020 Location: Brisbane, Australia Device: kt4	Sad news for those playing at home. I opened up my KT4, hooked up a modified USB to Serial adapter to allow 1.8V comms, and tried to talk to it at 115200 with no joy. I took some pictures, but I'm too new to attach files. Basically I soldered wires to the port that looks like a serial port in this thread: https://www.mobileread.com/forums/sh...d.php?t=267541 It's at the bottom right corner of the KT4 I tried swapping the TX and RX lines, that didn't work either. There was no communication at all, I tried disconnecting and reconnecting the battery while it was all hooked up to see if I could get something when it first started up. Also nothing. Reading that thread Dave suggested, and a bit more digging, I might have to wire directly to the processor, but it's under some EMI shielding, so I'll have to get a heat gun to it or something. There's also a chance that my voltage step down converter isn't connected correctly, so it's back to the drawing board. I do have a cheap oscilliscope, I'm just waiting on a replacement probe for it, so I'll try again when that arrives and see if I can see any blips on either of the lines