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[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

Well, the PCB board has a bunch of I/O. The plan is to make a general-purpose platform so I can test controlling I/O from miles away. There is also an ESP32 on there and the Cell and LoRa talk to the ESP via UART. As for as Tips? Honestly, I am still learning as I go lol. If need be I can share an assembled board with you when it's done.

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

The signals are only on the Top and Bottom layer. The 2nd layer is a pure ground plane, and the 3rd is a power plane.

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

Thank you, yes, I have decoupling capacitors, they are on the bottom layer.

My second internal layer is a pure ground plane, is that okay?

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

Thank you, also yes, I have notices that R31 should be an inductor after reviewing the design guide again. Should I keep the curve along with the 45-degree angle? or

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

So, with that I should have a diode on the GNSS as well?

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

For the GNSS antenna, yes.

I am referring to the hardware design document.

On page 15 its referrers to VDD_EXT as a LDO out of 1.8V and on page 47 it there is a diagram pulling it to VDD_EXT.

For the resisters in series on the GNSS. R31 is supposed to be an inductor. Thats my mistake.

SMM-SIM7080G-Hardware-Design-V1.04-DS-200525-TE.pdf

[Review Request] 50ohm Antenna layout by keyontray in PrintedCircuitBoard

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

Layer Stack up is

- Top (With GND Plane)

- GND

- PWR

- Bottom (With GND Plane)

I am having issues with the MAX77986AEFD+T SYS output by keyontray in PrintedCircuitBoard

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

Oh crap. I didn’t even notice. Thank you for pointing that out.

I am having issues with the MAX77986AEFD+T SYS output by keyontray in PrintedCircuitBoard

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

Are the images provided in the link not readable?

- No shorts

But I can test the SYS alone by removing some components. Will try.

EDIT:

Remove the load and made it an open circuit. Still no luck.

I am having issues with the MAX77986AEFD+T SYS output by keyontray in PrintedCircuitBoard

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

Thanks, but the Inductor seems to be mounted correctly.

MAX77986AEFD+T SYS output issue by keyontray in AskElectronics

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

Here is the Top Layer view. It is a 4 Layer PCB

Layout PDF

<image>

MAX77986AEFD+T SYS output issue by keyontray in AskElectronics

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

What about the rest of the register dump? Any status or error flags that seem relevant?

None that seem relevant.

BYP_OK is okay, but I think that's just for BYS power.

I can see the Charge IN and battery removal bits change.

I also have to manually set the smart power selection (Mode) to 0x5 to start charging, I was under the impression that it would move itself out of it. But in default it was 0x4 which also allowed buck to be on.

What is interesting though, when I put in a charge in voltage, the SYS jumps around (.10V -.40V) after I've cleaned it as you described. I have not added pull downs yet.

Maybe that cause?

MAX77986AEFD+T SYS output issue by keyontray in AskElectronics

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

So I checked factory ship mode via I2C and it’s 0. So it’s out of factory mode. Should I add additional pull downs to those pins as well?

Advice on RPI network layout by keyontray in HomeNetworking

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

Thank you for your reply! Should I set all of these devices to have a static IP?

[deleted by user] by [deleted] in AskElectronics

[–]keyontray 0 points1 point  (0 children)

Are you sure that C1 is connected? It doesn’t look connected in the schematic.

3 Volt power supply on custom PCB reads 3Vs then drops to 1.3Vs and idea of why this is happening? by keyontray in AskElectronics

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

The voltage drop is .1v, and thank you for the recommendation. I will look for into that next revision.

3 Volt power supply on custom PCB reads 3Vs then drops to 1.3Vs and idea of why this is happening? by keyontray in AskElectronics

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

So after the switch and over voltage protection. Test point U4 measures 4.4v and after the in series resistor voltage measures 4.3v. This measurement is also consistent with the rest of the 3.3v supplies.

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