Soldering Headers and GPIO access


As you can see I also like to use the extension headers on my Pi Zeros and pHats, thus allowing stackablity and access to pins at all times. I have recently looked into these low profile smt female headers like on the sense-hat, but alas, I haven’t figured a good way of soldering them being the pins are off to the side. These would be ideal and wish the Zero and pHAT PCBs allowed for them sense the extra long male header would push fully through allowing a new set of GPIO ontop of the smt header.


The header on the Sense HAT is really cool - it is great for stacking boards miles high.

If you want to solder them, providing they fit on the pads on the board, you should probably use some solder paste and a heat gun (being careful not to melt the solder already on the board). It’s gonna be hard work with a soldering iron (I would melt solder onto all the pins on the board and try and reflow it pin-by-pin).

The Sense HAT’s PCB was possibly custom-designed around this header, so it might not even be possible. Not all SMT female headers are push-through - most are just like normal but with SMT pads instead of thru-hole pins, I believe.

Good luck!


I think the greatest mod that could be done to the Pi zero series would be to make it compatible with the surface-mount pushthrough low profile header the sense-hat has. really adds re-usability of pi zeros from project to project. whether a female/male extension header is applied to it for double-sided accessibility, a right angle header inserted in it or just double length pins, the ability to have all these variations from adding the SMT low-pro header is ideal. I wish the protoboard and even some of the phats were compatible. Especially the pHats due to there ability to have be combined. I use extened headers soldered into a few of my phats that use few pins. Unfortunately this often leads a taller stack with bendable pins sticking up or an extra female header below. Harder to fit in some project cases.


That would be rather cool - but when you’re making a $5 computer you gotta make every saving possible. I suspect those headers cost a pretty penny - and would bump the price a fair bit.


If I read the first post correctly, the push through SMT headers would be on the pHat/HAT, not the Pi.


I used the tall stacking headers with my Proto Hat. I actually need the space, I have a DS3231 RTC board mounted on my Proto Hat. Plus some right angled headers.

Isn’t there an issue with multiple Hats/pHats if they both have eproms on them? As far as the Hat spec goes anyway.


I am not suggesting including the header just have the GPIO soulder hole/pads able to accommodate them. I have tried to figure a way but alas there just is no room with the test pads where they are located so close to the GPIO holes.


No. Have the pi zero accommodate the SMT header. If the GPIO holes solder pad area were a little elongated or had a slight side spur of area to solder to for the SMT header and the test pads on the Pi zero were a fraction away I could actually mount the SMT header. This would be an ideal way to solder most my pi zeros by default because of the variety of modes I could add pins or other headers. Take the spacers off an extended extra long header and its the same foot print to push through as would be solder. If the SMT header was on the bottom I could still mount onto a breadboard break-out cobbler type. I could also push through individual pins to connect a hat/phat on top yet have access for jerky wires from bottom giving me alot smaller height in a project. Very useful in building when you are not ready for a permanent fix yet.


Oh see. I need to look into the headers - they are much nicer and easier so
would be nice to include them in my future projects. Are the pads just
surface mount ones either side of the normal ones?


Couldn’t find it here, but Adafruit has it, It’s the same header that is on the sense hat.


yes. if there was just a hint more surface on the PCB to solder I could make it work but the tiny SMT pins extend into other areas of the board and will make unintentional contact with them. I bought mine from adafruit with the intent to solder on a pi but alas after much study relized even with it held in place with mechanical pencil graphite through the gpio in order to keep the holes open and not accidently seal I still ran into other areas of the PCB that would make contact.
Graphite is a great medium for hi-temp tools. nothing sticks and it is thousands of degrees heat resistant.