GPIO

[OLLYDOTDEV]

As an electronic engineer It is needed that a platform to interface hardware like sensor or Radio transmitters. As there becomes a point in Project Birdseye that data must come from hardware into a full data processable form with 1&0 this GPIO is where that happends

[OLLYDOTDEV]

for the SPI it needed to work out that was the interface it was connected to with the #16 so by using this command

how we can see that the

/dev/spidev0.0 happen to aline up with spi0

that knowledge will be used in #16

otherwise, that is all that is needed for this sprint.

[OLLYDOTDEV]

there see that I have tined the gold pads so that they are ready for soldering. then I tested to make sure that I hadn't shorted anything and it booted just fine.

(pi zero w with headers link to image as I forgot to take an image of this stage)

when I added the NRF24 #16 to the GPIO header but well it would not boot so then I moved on to soldering headers but after I had to solder the header the Pi zero w wouldn't boot so I tried removed the solder and It still did not work.

[OLLYDOTDEV]

So I thought that I had just got unlucky and shorted something when I powered while it was connected to the NRF24. so without looking to much further into in it I.

[OLLYDOTDEV]

so with having my first Rasberry pi zero w not working I was lucky to have one on standing by as a backup. so again I tined the pads on the pi and it still worked just fine but this time rather the putting headers I directly solder 7 jumper wires as seen below

the pins I soldered to were 3.3v, MOSI, MISO, SCLK, CE0, GND, GPIO 25 again it wouldn't boot so I when I started to worry no stores had any PI zero w in stock due to COVID-19.

Then I powered up the board after connecting the header (i had removed them my now to see if that fixed the issue ) and I here this https://youtu.be/H65ErzZNP3U so yeah not looking good.

so this time I got out my multimeter AND tested the continuity and I could see that the GND, 5v, and 3.3v were all shorted. Now I know that they weren't previously connected as a did of a test before it is any soldering thus mean something had shorted.

the first thing that comes to mind is my soldering on the GPIO pins, so using a microscope I inspected each pad individually on both sides. for examples of what I was looking at see the image below.

so keeping in mind that the width of one of those pads is about 1cm.

we can see that some of the surrounding solder mask is been burnt/scarped away with some excess solder at first I thought it might be shorting it to the GND plane but this can not be so as the ground plane is on layer 4. so might be still be shorting but I have evidence that might show there the issue is. now I repeated this process for all of the 7 pins that I soldered.

So my suspicions are that I could have damaged another component by heating it up too much.

[OLLYDOTDEV]

so to work out that part was the issue. I leave the RPI Zero w plugged into 5v till stuff started to melt as seen here charred parts is never a good sign. the part that was generating the heat was the DC to DC converter

the odd thing is that this DC to DC converter to noware near where I was soldering thus meaning that it must come down to being overheader whiles soudering the headers i could have let the solder iron on the pad to long causing the PCB trancs to heat up and in the then the DC to DC converter.

[OLLYDOTDEV]

This means that I now have two dead RPI Zero w's and with no shops selling it can am at a bit of a loss

so I have made three plans (in order of preference )

Plan A Reach out to some contacts in the industry and hope that one of them as an RPI zero

Plan B use my fall back plan and emulate HID with an ATMEGA32u4 instead of the RPI while it would get the job done it will limit the Functionalityof the project severely and this would hinder my interaction. the only main got'ya with this plan is that I would need to find an ATMEGA32u4 in NZ as from what I have seen is that they are few and far between seen being sold

Plan C so failing to find any parts in NZ to buy to do have some parts I all ready have on hand that I would be able to DIY together.

Arduino pro mini

digispark attiny85

I would need to use the combined features of both to be able to complete this function of this project as having automatic HID input into the computer. These are the main features I need from each IC. From the Arduino pro mini, it would be using its SPI interface and it would be the master controller for the Relay, As for the attiny85, it is able to act as the USB HOST for a virtual USB 2.0 keyboard. yes, the attiny85 does have SPI for is lacking the Extra data pins to control the NRF24 as two USB of the three Digital IO pins.

[OLLYDOTDEV]

I manage to find one more RPI zero w through contacts that all ready has the header solder on meaning that i should have the same issues as last time

[OLLYDOTDEV]

with this RPI zero the header this concludes all the work that needs to be on the GPIO