Soldering Components to PCBs

For any and all PCB components of the eVOLVER setup, is there documentation of the exact layout of what components should be soldered where?

New to the eVOLVER community myself. I just bought all the PCB components I need from PCBWay and am ready to start fusing it all together!


Hi Yasheen,

Welcome to the community! Happy to have you here!

Which board specifically are you asking about? For the vial board, the silkscreen should be pretty clearly labeled as to what goes where, but if you have more specific questions I’d be happy to help.


I guess I was referring to everything besides the vial board. I purchased the RPI hat from you guys so I’m good there. But the other PCBs I’m a little lost with some of the abbreviations on the silkscreens. I also purchased the more updated opensourced revision designs for the PCBs so they don’t look exactly like the ones in the paper for me to go off of that.

Is there by any chance some sort of key so I can be certain I’m soldering the correct components?

If you have the KiCad files you can cross reference the schematic and board layouts that to make sure you are placing the parts appropriately. If you select a part in one of the windows it should also highlight in the other. For the ADC and PWM boards, there should be a repeating pattern for all 16 channels, so once you get going it should be pretty straightforward. I also recommend using a needle point soldering iron tip for the small 0603 parts with a very thin solder, < 1 mm diameter should work well.

Have you already purchased components or do you need a parts list?

Thanks so much! I’m purchasing kind of as I go, but a parts list would be phenomenal if you have one!

My email is

I don’t have an up-to-date parts list (parts become unavailable all the time, and we usually just buy our PCBs pre-populated from Fynch), I was more just trying to see where you are in the process. In general though I’d say to use the KiCad files as a guide - everything should be clearly documented in those files. I can try to help with part selections if there are parts you can’t find.

Hi, @heinsz

I have one more question about the KiCad files. What does it mean when one of the parts says OMIT underneath the footprint description. Like R2 in the screenshot I attached? Should I still solder a 10 K resistor there? Thanks for the help!

It means do not put anything in that spot. The footprint is there to allow the gain of the circuit to be modified, but it’s not needed for most applications.


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Hi, @heinsz

I had a few more clarifying questions here.

On the kicad file for RS485 there are five capacitors, C3-C7 that do not list a capacitance for them. Is it safe to assume C3-C7 require 0.1 uF?

On the motherboard kicad file, what is required for the 3-pin jumper receptacles (for example, in the attached image there is one with pins marked 24 volt, P39, and 5 volt)?

And final question, in the last attached image, what part goes to the 6-pin footprint marked J4?

Other than that I think I am all set with soldering and ready connect everything together and start calibrating my equipment!

Hi @jadidiya,

C3-C7 on the RS-485 board should have 0.1 uf, 10 nf, 1 nf, 100 pf, and 10 pf, respectively. It’s a noise filter.

For the jumpers, you can really put any jumper pin. That is there to allow you to select 5 or 24 volts for any given parameter channel. So for instance, for the OD slot, you would put a jumper between the middle port and the 5V port. STIR would require the 24V port have the jumper and not the 5V. There are parts that you can solder in that allow you to pull the jumper in and out so you can change the voltage if you need to modify the channel without additional soldering, but I don’t have those part numbers in front of me and I’m currently traveling. Maybe @bgwong can provide that.

J4 on the motherboard does not need to be populated.


One thing I forgot to mention - for the jumpers, make sure they are decently sized. You don’t want to use thin wire for those, use something close to the diameter of the hole.


Hi, @heinsz
For resistor footprints that have a value of ‘R’
what type of resistor should I use if I do need to add a resistor?

I am looking at the kicad for vial board Rev C

Thank you!

You can use 82 ohm resistors for all of them. You do not need to populate R4 - the footprint is there for future design ideas that are not currently implemented.


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