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To: Bobalu
My FRA contracts used PC104 running Linux or QNX with custom, stripped down kernels with BusyBox for utilities and custom code to drive the GPS, A2D board and CAN controller. The PC104 had an Ethernet to 802.11b converter with OLSR mesh networking in place to span up to a 255 car train.

The cars have accelerometers that support +/- 80g at up to 100 KSPS on the bearing adapters to perform spectral analysis of the cup/cone/cage/roller vibration. PIC18F6680 MCUs provided the CAN interface and a German supplier provided the CANopen embedded libraries. I designed and programmed devices to service a tri-axial accelerometer on each bolster for ride quality assessment, temperature sensors, a handbrake controller, an anglecock controller and a brake piston position sensor. Wilcoxon Research provided the accelerometers and did the CAD, fab and packaging of each controller. A dedicated PIC16F device monitored the 12 pole tachometer output of the Timken generator to determine car speed over the track and the threshold speed for making net charge to the system battery vs load. The 16F "pushed" the "power on" button and reported battery voltage.

I published a paper at the 10th Annual CANOpen Conference in Rome describing the Onboard Continuous Monitoring System. A related paper was published for the ASME/IEEE in Pueblo, CO a couple months later. More details than are suitable here. I love embedded and kernel work, but it is hit and miss on opportunities. Customers want systems moved "to the cloud". Lots of Java, Docker, kubernetes, Kafka, helm, keycloak and whatever UI framework is popular when the proposal is being written.

One of my co-workers was doing custom Xilinx devices to do DSP with sample rates in the 400 MSPS range. My tasking on that project was real-time stream compression. Never a dull moment :-)

47 posted on 07/06/2022 4:52:02 PM PDT by Myrddin
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To: Myrddin

CAN and ARINC work is always a little nerve-wracking since you are dealing with safety issues on every hand.

I’d sure hate to be the guy who’s firmware caused a disaster :-/

Imagine the hand-wringing and grief that must have resulted from the recent Boeing fiasco with the flight control on the 737 MAX ...

Working with biomedical devices is similar... you can leave NOTHING to chance.

It’s nice to be able to just create hobby projects now, no one is gonna be in mortal danger :-)

I enjoy playing with simple AVR projects and prefer DIP packages to avoid the hassle of having boards made... I often do dead-bug soldering, it’s a fright to look at but once the project is in the cute 3d printed enclosure who’s gonna know...lol


52 posted on 07/07/2022 10:45:24 AM PDT by Bobalu (A dem asked what side I was for in Ukraine, I said "I'm against the commies" -- He got real pissed!)
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