pojd / can-pcb Goto Github PK

wire up the connector to the cable and test I can easilly plug it in, otherwise I may need to change this component on Relay too.

2A or perhaps even just 1A to protect the circuit and power adapter from blowing. Perhaps optional on CanRelay. Somehow make it optional via a jumper so that only one relay will actually have it. Also buy it front GME then.

Mirror the pins and use additional 2 for GND and 2 for PWR. And update schematic desc to use custom CAT5 wiring so that PWR is always twisted with GND, the same for CANH and CANL (already the case)

• - https://www.gme.cz/rj-konektor-webp-8-8-pcb - single RJ45 plug
• - https://www.gme.cz/ark350-3-blue - 3pin connector for usbtin
• - https://www.gme.cz/napajeci-souosy-konektor-pc-gk0-65 - power adapter (hopefully correct this time round)

May become handy if voltage drops between relays is too high, calculate the voltage drops. At home with 4 nodes and roughly 15m CAT5 cable, first node had 5.1V, while the last one had 5.0V only, i.e. 0.1V drop across 15m. So over 90m I would get down to 4.5 only, which is absolute minimum.

Since running CAT5 to individual light switches would be a nightmare. Use something from this for example: https://www.gme.cz/nasuvne-vidlice-zasuvky-do-dps?price=1;354&tech_par[172][]=8061&showFilter=172&page=1#products perhaps in time with a wire secure like https://www.gme.cz/kabelova-prichytka-samolepici-kss-10j-s-14mm

Shoot for 9 pins so that we can eventually connect all 8 input pins + GND. Rename wiring accordingly in CanSwitch then.

At times it seems the resistors at least have too much space around them in PCB causing the soldier to run through. Check data sheets for both resistors and capacitors and other components and confirm/adjust the lead width

Think over better ground for XTAL

without this a lot of spurious triggers happen

Page 6 in datasheet, all physical components already ordered, so just lay it out on the schematic

Now it has just 1. Also put another RJ45 socket on the board for the additional switches. Even for 1. So that it snaps to the PCB and just the other side is using single wire connected.

Page 49/622 in datasheet talks about it in more detail

so that I can increase the output count from current 19 to up to 30 (35 minus CAN minus xtal minus MCLR - that can also be used as RE3 input only pin)

stress testing. wire up all input pins of all can switches together to be able to simulate all switches at once. observe the current drawn.

so that we can connect the power and ground from the end points (CanRelays) to have the biggest consumers the closest to the power source so that the current has the shortest path to the most draining parts and rest of the power line therefore shall not see that much voltage drop.

Use unused pins for PWR and GND, match CanRelay, so that the same twisted pairs exist and are connected

This would allow the PIC to move transceiver to standby mode in sleep mode of the PIC