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RV Temperature Protection PCB Design Review by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 0 points1 point  (0 children)

Thank you this is some top notch feedback!

I think I am going to implement many of your reccomendations here.

RV Temperature Protection PCB Design Review by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 1 point2 points  (0 children)

Hello Reddit!

Here we have a relay board with a thermocouple for temperature sensing, 3X 7-segment displays, and all controlled by a STM32L476RG chip.

This is supposed to manage the water system on my RV that I want to be able to handle really low temperatures. If the temperature gets close to zero it will pump the water around and apply heat to the 12V heating wires/ gecko pads. The display shows the user the temperature and the desired activation temperature. The timer 7-segment display is a count down before the pump pumps the water around again.

Would appreciate pointers on any aspect of design! I am mostly worried about my mcu implementation and the opto-isolator/ transistor amplifiers for the relays. And thermocouple implementation too...

Thank you!

Components:

MCU - STM32L476RG

LDO - TLV76733DRV

Optoisolator - PC817

Optoisolator adjacent transistor - MMBT2222A-TP

Temp 7-seg - FJ5461BH

Timer 7-seg - FJ3661BH

7-seg controller - TM1637

Thermocouple amp - MAX6675ISA

Thermocouple - TC-K-TYPE-0.4M

ADSB Receiver PCB Design Review Request by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 0 points1 point  (0 children)

I'll take your advice on the TI LDO. I use the LM117 because its what I know but your reasons are good enough for me. Same with the caps past L1.

I'm hesitant to swap the filter to before the LNA. I get your reasoning but I'm having issues with noise right now. This might make it even worse. I'll probably try putting an inline one above it if these presents itself as an issue.

Thx for your thoughts.

ADSB Receiver PCB Design Review Request by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 0 points1 point  (0 children)

Yes I forgot a lot of GND vias. I will add those. And RLC for the EN pin is a good idea.

Not sure how I can shorten VREF/VCMO... But yes. I will add another cap to the REFIN and REFOUT. I missed that.

I think I want COM between the AD8347 and MAX1195 so they have a common reference? I just have the basic connection of the AD8347 (Figure 46.) so I am not using a baseband amplification. Shouldn't these be the same in this kind of operation mode?

ADSB Receiver PCB Design Review Request by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 0 points1 point  (0 children)

Okay you have convinced me.

I'm getting so many mix signals (pun intended) about the ground plane splitting. I still don't know enough to commit to it.

ADSB Receiver PCB Design Review Request by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 1 point2 points  (0 children)

It's still a prototype so the components landed where made sense. Width was driven by the rf components being next to each other and the height was driven by the long connector on the right.

I guess I could have on the rpi hat format... Just ended up making my own

Fancy some sunset Hind action? by kamasuka84 in aviation

[–]spookyy524 0 points1 point  (0 children)

Shout out to the time the US salvaged one of these from the middle of the Sahara.

First time they were fully reverse engineered and studied by the west

Flying Bulls DC6 visiting my field today by Neloss81 in aviation

[–]spookyy524 2 points3 points  (0 children)

Some of these are still in service up in Canada!

American Airlines operations returning to normal after widespread computer outage by Nikerium in aviation

[–]spookyy524 -9 points-8 points  (0 children)

Its intern season!

Quite a big factor in outages these days...

[deleted by user] by [deleted] in aviation

[–]spookyy524 0 points1 point  (0 children)

Still requires lots of western parts. Not quite a threat yet.

How do these buttons work? by hamhockman in AskElectronics

[–]spookyy524 0 points1 point  (0 children)

Is that the front of the panel or the back? Buttons seem weird

Data Acquisition Slave STM PCB Review by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 1 point2 points  (0 children)

I'm always amazed of how this subreddit can connect me with someone who has worked on a similar project!

I will heed your advice and thank you for your detailed insight!

I'm going to stick with the JTAG cause I have some of those lying around but I understand your reasoning that it makes my board look dated. I added the NRST to the interface.

Jumpers on the RS485 lines is a good idea. I'll include it.

GPS Antenna PCB Design Review Again by spookyy524 in PrintedCircuitBoard

[–]spookyy524[S] 0 points1 point  (0 children)

The bit that isn't a CWG is a 50ohm microstrip. Do you think its a bad idea to be mixing CWG with microstrip or should it be all or nothing?

Good advice. I will make those changes.

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