20131021o
How is my last log from wednesday? I know I was at the lab on friday, albeit I didn't get much done and can't remember logging anything really. But what the hell happened with thursday?
Oh well. I guess we'll never know.
I'm going to look at the schematics because that's what Rune says needs doin' in his last log, 20131018r. It also says that the board should be prepped for production but I'm not entirely sure what that entails so I'm doing the looking bit first because I might not remember what I spent my thursday on but I've still got functioning eyesight.
- Should we re-label everything in the schematic?
- We are missing LED 1 and 3 (they used to be on the PSU schematic).
- Also some components start at 0 while others start at 1.
Like, the amount of each component on the board? Ungh you know what, no. I'm going to look into how to prep it for production.
- When trying to generate gerblerlrlr files Altium returns an error stating "The Film is too small for this PCB."
- According to http://wiki.altium.com/pages/viewpage.action?pageId=12125605 it's either because the film is too small or due to off-board objects.
- I removed the off-board objects and saved the document as barricelli2.pcbdoc. Comparing the two files using
Project -> Show Differences - Oh wait no "show differences" displays the differences between a pcbdoc and the project's design hierarchy. That's not what I want. Although it sounds like something we should do before shipping it.
- I reset hard to HEAD and created the branch
b4-prodprepto serve as a bookmark from before I started trying to prep the board for production. - Also I made a branch called
prodprepand switched to that.
From the 256SoG report:
- They spent two days (TWO DAYS) manually routing to reduce the number of vias. They do not specify how many they managed to get rid off, nor how many they had when starting out. Nor do they state how much it reduced the production cost.
- There's nothing in the section about the PCB design process explaining how they got from routing to production.
- However it seems to be covered by appendix B.3 - Macaos.
- Wait, shit, have we applied for a macaos license? I'mma go ask Tufte about this.
- Tufte's office was closed and Odd Rune was in the break room talking to some guy so I'll check back later.
- Wait no I'm just going to apply for a license just in case.
- Well that was painless. Also the form seemed vaguely familiar. I wonder if I've filled it out before?
Error appears when generating gerber files.
See Why do I get the error "The Film is too small for this PCB" when generating Gerber files? on the altium wiki.
- There were a couple of components just floating about outside of the actual board.
- THEY WERE REMOVED.
Using Select Outside Area (S O) and dragging the selection around the PCB selects the following components
- the silk screen text "Datamaskinprosjektet"
- Fixed by moving it slightly to the left.
- USB port
- Serial Port
Hurr durr. Setting the film size to some silly large amount (like 1000x1000 mm^2) makes the error go away but the resulting .Cam file tells me nothing. It's just blank.
- The USB connector slightly overlaps the edge of the board.
- Follow-up problem: There's a via like right behind one of the USB's pads/connectors. See
- Thing is the via's on top of two cables and I don't know how that's supposed to work. Moving just the via seems to derp the wire placement. I'd say we should autoroute again after moving the usb slightly, that's probably for the best.
- Where does the components' silk screen labeling come from?
- It seems to be manually applied to a lot of components, because they don't always correspond to the labels in the schematic (schdoc) files. For instance: INST.MEMORY 0 / IMEM, DATA MEMORY / DMEM.
- Step by step, how does one use harnesses in Altium?
- What design rules did we use and where did we find them? Like, we need a link or something.
- While viewing the pcbdoc, altium can generate a list of links between the components in the pcbdoc and the related schematics:
- Project -> Component Links
- That could be useful for the report, if the generated list contained the component's labels.
- A brief explanation of (de)coupling:
- Coupling: transfer of energy from one medium to another medium. Or from one circuit segment to another. E.g. between wires or power layers on a PCB. Wikipedia.
- Decoupling: the prevention of undesired coupling (between subsystems). Wikipedia.
- Capacitors can be used for decoupling by placing them physically close to the component you want to prevent coupling at because they charge up and store energy so they "act as small localized energy reservoirs that supply the circuit with current during transient, high current demand periods, preventing the voltage on the power supply rail from being pulled down by the momentar current load."
- Decoupling is also explained in Fortitudo Floris' report (3.3.2 Decoupling capacitors and noise reduction)
- Board specs: 154mm * 154mm, border: 1mm