2017-10-01
Today I was working on my power and serial expansion board for the Beagle Bone Black. This board provides 5VDC to the BBB, breaks out the RS-232 ports, and sequences (or is supposed to anyways) the power to the RS-232 transceivers and the IO board. All that because the BBB can not have any power applied to any of its input pins until a specific pin goes high indicating that the processor has found its Read more…
2017-09-30
How do I put this. Version 1 of the board is done. The pictures below is the first board assembled on the final revision of the PCB. It says revision C, but it’s really revision D. The only difference between C and D is that I made the holes slightly bigger for the drive FETs in the output over-current protection circuits. This batch I had manufactured by Elecrow (https://www.elecrow.com/). I’m fairly satisfied with the results. Read more…
2017-09-17
So I am going to go ahead and open with this. Those are the stats for the ‘LOGIC_CORE’ piece of the software stack. For those not fluent in gibberish, what this shows that after an hour of something like half-dozen threads grinding away at the IO board communicating with an “end user” process no memory errors have been encountered. No out of bounds writes, nothing was lost after allocation, etc. What this means is that Read more…
2017-09-09
It appears that I am incapable of taking a decent picture. I guess I am not perfect after all. All of the pictures below were taken at the same time. Well OK technically not at the same time; they were taken in a serial fashion. They were taken during the same picture taking session. Why some of them look like a teenage girl applied some sort of social media photo filter on them is beyond Read more…
2017-09-02
Note: Last time I did web development was in 2010 or thereabouts. At the time I was up to my ass in JSP, servlets, beans, rice, J2EE, jQuery, etc. So I’ve been out of the game for a bit. I certainly hope that I’m missing something. Some sort of piece of underlying logic that ties all of the nonsense together and converts it from “uhmmm this is kind of bulshit” to “oh ok that makes Read more…
2017-08-15
So it works. My IO board that has been in development for 7+ months works. The hardware works. Sure there are some warts that need to be addressed in revision C, but it works. It is functional. The firmware works. The CLI-style human interface works and the binary machine interface works. Sure there are some warts, but it works. The Linux portions, the multi-threaded, multi-process, bi-directional serial stack, and misc works. The human interface component Read more…
Revision B of the board PCB came in and has been assembled. All of the issues from revision A have been addressed. Did find a couple of issues in this revision though. I added microprocessor sanity checking circuitry and IC. It does not work at all. On the PIC24 it keeps rebooting the chip on the dsPIC30 it prevents the ICD3 from connecting to it. I will be ripping it out in rev C and Read more…
2017-07-31
I’ve made a huge mistake While waiting for my boards to come back from fabrication (they should be here tomorrow OMG SQUEEE) I decided to do some software work. Early on in the process I made a slight little design error. I made the piece of the stack that’s gonna live on the Beagle Bone a bit more complicated than it really should be. Naturally, rather than admitting my mistake I plowed forward. At this Read more…
2017-07-18
So many failures, so little time More failures. Apparently the driver IC I chose to drive the digital outputs is an N-channel driver. Naturally I had it trying to switch +24V. I know what you’re saying: hey Vic, you stupid, you’ll need a charge pump in order to bring the gate voltage above the source voltage. I did not have nor am I willing to incorporate a charge pump. Another failure was failing to properly Read more…
2017-06-24
The turkey has landed The boards have arrived and the lost Digi-key order has been retrieved. The folks where the package was erroneously delivered were kind enough to reach out to me and I picked it up from them. Assembly wasn’t terrible. Almost everything fit perfectly. I must have double-dosed my stupid pills the day I laid out the pads for the fuse holders. Apparently they’re 9mm wide and I, for some reason, allocated 6mm Read more…