blog

date: 2024-10-22 00:16:35 projects: skipper
ive decided. the SDM3055 will first gain a SDM3055 driver which does not use the scancard. this will implement a new DMM interface

when the SDM3055-SC driver with scancard support is written it will implement a new scanningDMM interface

there is now also some minimal support for gitea actions


date: 2024-10-21 21:07:09 projects: switchBox
the PCB layout is now generally complete. it just needs some silkscreen fanciness and a final look over to verify that the tracking is sound.

i may put some form of protection on the ethernet lamps, they dont have any right now

i put the design into aisler to get a RoM cost on the PCB and it is expensive at about £50 per PCB and MOQ of 3 which gives a total PCB cost of £100 per switchBox. this means it needs to be as close to perfect as possible as its very much a oneshot as theres probably about the same in components on the PCBA still, it should be fine...right?


date: 2024-10-20 21:45:58 projects: switchBox
after too many hours of searching for 5mm requirement clearenced ethernet connectors with no success i give up. this design will have to have the PCB butting againt the chassis panel. the USB connector will be reworked to provide the same amount of edge overhang as the ethernet connector

the contact connectors were revisited and actually the chosen part was fine, the model was incorrect but the chosen part was fine and its BoM information is now populated

the PCB is almost done just needing:-

  • ethernet
  • silkscreen tidying
  • routing final look
  • DRC
  • any additional silkscreen

then it will be on to software! its been a long time coming


date: 2024-09-30 21:12:56 projects: switchBox
relayout in progress.

there are several component changes to make, they are:-

  • longer ethernet connector - there is a 5mm pcb overhang requirement to allow connector access through the chassis wall
  • contact connectors - when originally specified, there was insuffiucient bill of materials data and they are fairly tall

i will also need some series resistors as the traces are a bit long...


date: 2024-09-23 22:05:34 projects: skipper
the next device that will be supported by skipper is the siglent SDM3055-SC. i have not yet decided whether to support the front panel or scan card first; there is a forced exclusivity between the two as when the scanner card is active, the chosen input is routed to the front panel

this will lead to a new DMM and scanningDMM? interface. the interface name for when a DMM with a scan card is used is currently undecided as this may fit better under a DAQ label but this is uncertain as i have not looked at DAQ that deeply