u/ItanMark

This is a PCB I recently designed as a beginner under a very tight deadline. I do acknowledge that the routing is quite messy, but I had limited time to optimize the layout. At this stage, my main priority is ensuring the board will function correctly before ordering.

The PCB is a flight controller (yes, another one) combined with a data logger and equipped with a LoRa radio transmitter. It is based on an RP2040 microcontroller, with all modules communicating over an SPI bus. Power enters through an XT-30 connector, passes through a separate off-the-shelf buck converter daughterboard, and then powers the rest of the board. The board will also be connected to a second, external battery through the pins on the bottom side of the board, so I added diodes to ensure the batteries do not charge each other and essentially function in parallel until the external one is disconnected.

The PCB is also equipped with miscellaneous features such as pads for soldering on a servo, a voltage divider to monitor LiPo battery voltage, solderable GPIO pads for future expansions, a power LED and a buzzer.

I also went with an active antenna for the GPS, so I implemented a bias tee according to the manufacturers specifications.

I know the silkscreen looks horrible, I will fix that later before releasing the board on github.

The modules were positioned to minimize RF interference and improve gyro and GPS accuracy. Due to time constraints, I am unable to redesign the board or significantly clean up the routing, so I am primarily looking for feedback on issues that could affect functionality. That said, I am eager to learn and would appreciate any advice or suggestions.

I would really appreciate advice on the power section of the PCB, as that is where my knowledge is very limited. Though I tried to simplify it as much as possible I am still unsure it will function correctly.

Components:

• U1 – RP2040
• U2 – MPU6000 gyro/accelerometer
• U3 – u-blox M8 GPS module with a bias tee for the active antenna
• U4 – BME280 barometer/temperature sensor
• U6 – Ebyte E22S400MM LoRa transmitter

Attached below are the links for the documentation of all the modules and to my design

https://limewire.com/d/z6aJA#wKS6P63EP9 - documentation

https://limewire.com/d/wRtpG#YSVZVOkbgm - the board itself

Screenshots:

1. All layers except planes
2. Top layer
3. Bottom layer
4. Ground plane layer (L2)
5. Power plane layer (L3)
6. 3D render
7. Schematic
8. Active antenna bias tee
9. Power area (careful, extremely messy)
10. RP2040 and its connecitons
11. SPI bus
12. Flash area

Attached is my design of thr SPI communications. I tried to use as little transitions to the other side as possible and reduce the total number of vias. Does this actually help the signal integrity or anything else or should I overthink this less?

Hello!

I made a similar post about a week ago, and got criticism for an unreadable design. I have now remade it and hope you can help me point out some more mistakes.

The actual board will be assembled with all SMD components due to size constraints and will be a circle 60mm in diameter (or a "stack" design, I will see if I can fit everything onto one board).

It will be powered by a 2S LiPo/LiHV battery, hence the buck converter. The aim is to have a lightweight board capable of sending and recording telemetry while also being able to trigger a parachute deploy system (hence the servo).

The components include:

• RP2040 microcontroller
• E22-400M22S LoRa 400Mhzradio transmitter
• Neo M8M GPS module
• MPU6000 accelerometer and gyro module
• Bosch BME280 barometer and temperature sensor
• Texas Instruments TPS563200 buck converter module
• Servo for the deployment system

I also appreciate any and all advice as to routing/board design.

Screenshots:

1 - whole design

2 - buck converter circuit

3 - modules and their connections to the RP2040 (GPS, LoRa, gyro, barometer...)

4 - RP2040 and its components (oscillator, flash, USB)

I am open to any and all criticisms and thank you all for your attention!

Here is a link to the schematic in PDF format: https://limewire.com/d/iRRxE#QUbLTdlpXy

Documentation and datasheets for all modules: https://limewire.com/d/tUnTL#3r7Ob76MEG

Hello!

I am a beginner engineer and am building this flight controller for a model rocket. So far I am only in the schematic stage, but I feel like it is very important to ensure you have a correct schematic before actually routing anything. I would really appreciate if you could point out some flaws and mistakes I (probably) made.

The actual board will be assembled with all SMD components due to size constraints and will be a circle 60mm in diameter (or a "stack" design, I will see if I can fit everything onto one board).

It will be powered by a 2S LiPo/LiHV battery, hence the buck converter. The aim is to have a lightweight board capable of sending and recording telemetry while also being able to trigger a parachute deploy system (hence the servo).

The components include:

• RP2040 microcontroller
• E22-400M22S LoRa 400Mhzradio transmitter
• Neo M8M GPS module
• MPU6000 accelerometer and gyro module
• Bosch BME280 barometer and temperature sensor
• Texas Instruments TPS563200 buck converter module
• Servo for the deployment system

I also appreciate any and all advice as to routing/board design.

Screenshots:

1 - whole design

2 - buck converter circuit

3 - modules and their connections to the RP2040 (GPS, LoRa, gyro, barometer...)

4 - RP2040 and its components (oscillator, flash, USB)

I am open to any and all criticisms and thank you all for your attention!