2017-05-06
Finally real progress is being made. The I2C communication stuff is working on both chips. I’m taking the register-based approach and have tested the implementation of all of the basic registers. Did a bit of stress testing on the communications stuff – weird input, input overflowing buffer sizes, collisions, and etc. and everything seems to be working fairly well in a sense that there’s no corruption, the failures are predictable and graceful, all data gets Read more…
2017-04-30
It has been a while since the last update and for good reasons. So after screwing around with the DAC on the BeagleBone I decided that I really didn’t like it. What’s with this 1.8 volt max nonsense? Now I’m no EE, so please forgive the laymen’s terminology. The BeagleBone has a 12 bit ADC on-board which means that it can split the supplied 1.8V (max) into 4096 discrete steps. Which works out (if my Read more…
2017-02-17
This update has been a while in the making. Between the last update and this one I accidental adopted a dog. That little shit machine has been a time sink. The Hardware Portion So anyways, the previous objective was to interface the NASA quality 4-20mA current loop simulator with the BBB. Several related and unrelated issues had to be address A bit tangential, but the GPIO pins are high when the BBB is first turned Read more…
2017-01-08
The Software So the next goal for this project was to get the BBB (Beagle Bone Black) to be able to drive digital output and to setup the reading of values from a 4-20mA current loop. Googling on configuring a GPIO pin to output with pull down resistors sent me down the rabbit hole of Device Tree overlays, kernel drivers, subsystems, SysFS, and so forth. Spent two days in the fuckery that is Linux documentation Read more…
2017-01-04
Got a chance to play with the Beagle Board. Installed the latest Debian Jessie IoT image[1]. Supposed to be an alternative distribution that removes all of the GUI stuff which sounds perfect for this project since all that this BBB is going to do is sit in a closet and pretend it’s a PLC. It’s certainly much more svelte than the default distribution with X11 and what not, but it’s still bloated in my opinion. Read more…