4D Systems LCD 4DCAPE-43T Touchscreen jitter

While upgrading my Beaglebone Black with 4D Systems LCD 4DCAPE-43T to Debian 8 I discovered that the touchscreen wasn’t working anymore. Digged a day through software with no result. Then I was checking hardware and found interferences on the 4 analog signals of the touch screen, that were obviously caused by the LCD driver. A internet search brought up this post: BBB and 4DCAPE-4.3T cursor jumping. So I gave this 1nF capacitors a try and finally the touchscreen on that LCD is working rock solid.

A sure indication of the problem is that ts_calibration from Debian tslib isn’t working and reads “Took 1 samples…” for all 4 axis. Also ts_print_raw shows readings while not touching the screen. Continue reading


My ADSB Receiver Box – Temperature Sensors – Upgrade 2

The ADSB receiver OS image that I use provides several performance graphs including the CPU temperature. For receivers installed on a remote location that is maybe not enough to monitor what’s going on inside and outside the box. For that reason I decided to install additional temperature sensors in my ADSB receiver box. My choice was the the Dallas DS1820 1-wire temperature sensor. It’s easy to interface to an Raspberry Pi and the kernel comes already with drivers. Perfect for that purpose.

This upgrade is divided into two steps: 1. Connect the DS1820 to the Raspberry Pi and configure the kernel drivers – 2. Reconfiguring the collectd service and the shell script that is creating the performance graph so that the additional temperatures will be logged and plotted as well.

DS1820 sensors measuring inner and outer box temperature

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