2017-12-30
Note: I was wrong in the last post. It’s the dsPIC that has a broken UART, not the PIC24. For the last month I have been doing the very unsexy work of grinding out bugs in the code. As I hinted at before my software stack had issues under load. I chose to test the full stack (hardware and software) by subjecting it to a completely unrealistic load. The logic behind it is that the Read more…
2017-11-18
I have been working on finishing up the software related to the board. The only feature that I had left on my wish-list was implementing the calibration stuff. The goal was to have the calibration offset be stored in EEPROM and for it to be adjustable via the text/cli interface and via the binary protocol. The process was going to touch the graphical interface piece, the middle-ware that sits between the interface and the board, Read more…
2017-10-22
I am a firm believer that the tool a man uses to should conform to the man not the other way around. If, for example, I need to remove a Phillips-head screw I will not take a slotted screwdriver and forge it into a Phillips-head screwdriver. I will take a Phillips-head screwdriver and use that. In other words I will use a tool that is conformed to the me and my current need rather than Read more…
2017-10-08
Second board is complete. Here are a few pictures of the two boards mounted together. That’s total of eight ICTD inputs, eight 4-20mA current loop inputs, and eight digital outputs. Now I need to find something to control! Next update will be about yet another major screw up of mine.
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…
2017-08-15
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…
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…
2017-06-18
Well the boards have been lost in shipment along with a Digi-Key order. Two orders in the span of two days. Not even properly lost. They were delivered to the wrong address. Through complete and total incompetence of the USPS I received junk mail destined for 1234 Street A. I live on 1234 Street B. According to Google maps that’s a neighborhood two streets over so it’s probably the same mail route. Put two and Read more…
2017-05-31
The board circuit design and schematic are done. This is pretty terrible picture export. I couldn’t figure out how (spent 15 seconds) to export an SVG of the board without the copper fills. And here is the 3D rendering. A lot of 3D representations of components are missing, but the general gist is conveyed. All of the design work was done using KiCad (http://kicad-pcb.org/) EDA. Which of course means that I had to learn KiCad. Read more…