A taste of disaster — how I burned a Pi zero …

my father had got a Pi zero as a free giveaway from a circuit board company and he asked me to bring it up, to use in a more lightweight control role in future.

So I went ahead and programmed the latest Pi OS image onto a 32gb microSD card from a PC, using a USB adapter for microSD.

Next the ports on the Pi zero were different from the Pi4 I am using, one microUSB is used for power. The other microUSB I had to connect a USB hub into as there is no ethernet port, full size USB or wifi on this bare bones model (some models have wifi) — I needed a keyboard, mouse and ethernet connection(usb to ethernet dongle) which I put into 3 ports on the usb hub. Finally it needed a miniHDMI to HDMI adapter to connect connect a regular HDMI cable from the device to my monitor.

It booted up fine from the microSD card and came to the Pi desktop. Was noticeably slow vs my Pi4 which I have put a pic above, with a stapler on the side for a known reference. One can note the 4 usb ports and ethernet port on the Pi4 which makes it easier to use without external hubs and adapters.

Next, I wanted to try any device with it, but since the 40 gpio pins were not populated but just holes, one option was trying my Pi4 camera in the camera port of the Pi zero. However it turned out the Pi0 has a smaller size camera port and needs a kind of adapter ribbon cable to hook the camera at one end and go into the (small) camera port on Pi0. Note the regular ribbon cable is too wide to go into that port.

So I attached a regular USB webcam (seen in previous stories) into the external USB hub and tested it out to take a few snaps — it worked fine.

Now it was time to solder the pin header onto the 40 holes and make it ready for connecting to breadboards and sensors. This was where things turned south due to my own oversights.

I gathered my new soldering rod which had both a pointy and spade tips, solder and flux paste and immediately got to work without referring which way the pins should go on the board and which side should the soldering be done…confidence…

So turns out I inserted the pins the wrong way and started soldering on the side of the board which had all the components rather than the bare reverse side. This was to cause problems as we shall see…

It looked deceptively easy but turned out to be really hard due to the close spacing of the holes, often times solder bridges would form between adjacent pins which had to remelt and redo. The pointy tip was good at getting a precise touch on the pins but turned out to have weak heat transfer to the solder wire which took long time to melt…all this time my hot soldering rod was more and more in contact with the pin and the board surface around it. The spade tip had better heat transfer but tended to melt bigger blobs that would touch the nearby pins, leading to a redo — a proccess where the hot rod touched the board even more….I lost track of what all that heat may do to the components and circuits on the board, the whole board heated up and I could feel it on my hands holding it in position, though I put a blob of play dough below the board, still needed one hand to hold it steady and feed in the soldering wire to the hot rod…burned by finger a couple times when distracted and left burn marks on the wood table also (fortunately Ma does not come to this corner of the house much)

Anyway, took time but finally got done…the ‘look’ was a ‘better’ than last time, though thats not saying a whole lot. I used a sharp knife in between the rows and columns to weed out any last bits of stray solder bridging two pins.

But on putting power back on, it would never power up again…which indicates my soldering on the wrong side of the board had burned something out and I had a beautiful paperweight, a talking piece for any party but no more a functional Pi0 … :(

Morale of story — need to watch or read a bit first before attemping something delicate where failure leaves a permanent impact. Equipment wise, not a huge loss, but it stings…

The soldering should have been on the reverse (flat) side of the board with no sensitive components (first pic), and also the black plastic bits in first pic should be on the sensitive side with the pins sticking out — I inserted it reverse. Second pic shows the soldering on wrong side. will remember this episode — a burned child dreads the fire! A inadvertent success in first attempt would not make me think why it worked or remember much.

With the Pi0 gone, will turn to attention to a Arduino mega I have and look into how that works and bring it up next. A lean microcontroller board without a persistent OS/sw like Arduino and its cool shields concept of stacking on boards should be interesting vs a full featured ‘fat’ microcomputer like Pi. I have heard its programming language and IDE is very different from how the Pi is used. (and…I already ran and checked — it has pre soldered pin headers — thank god :))