Author: db
USB OTG power, take 2
bq27541, smb345, pm8921 (all in drivers/powr) and ektf3k (drivers/input/touchscreen) seem to know when power state changes. The latter relates to slimport hdmi and receiving power through it. drivers/usb/otg/msm_otg is the other spot the work happens The BQ27541 is a ‘fuel-gauge’ and the data sheet shows it is not involved in decisions about charging. There is…
Graphing bandwidth of a pcap file on arbitrary granularity
OK it seems like i’ve done this enough times in my career w/ 1-off command line, i thought i would share w/ the group. This may not have the mass-market appeal of the cat videos, but its probably better for productivity. The below script will take a capture file, and then graph it’s bandwidth on…
Wiring for dash
The wiring diagram for my factory radio is here. You can tell which specific radio you have by looking in the glove box and seeing a bunch of 3-letter RPO codes (GM) and matching, or by follow the picture here. In my case I have a US8 radio (from the sticker in glove-box): Which…
USB OTG Charging, Nexus 7 Flo (2013)
OK, so the USB OTG works just fine, i’ve added the driver for my ‘easycap’ for rearview-camera, and enabled module loading. Now to dig into how to enable the use of charging while using USB OTG. In the msm kernel directory, there is a file ./Documentation/usb/msm_otg.txt. We want ID_A: Configure device to act as host and…
Starting on the Nexus 7 build etc
So a big change in plans. I bought a used stock AM/FM radio for my vehicle (2011 silverado), and removed the guts. the new N7 is slightly too wide, so a bit of dremelling was needed. Have acquired a single-wire-can to differential canbus converter and a usb canbus reader (for the low-speed canbus, e.g. steering…