norns shield

ed: I'm delaying this article forever because I'm still sad about this failure. Let's start from the beginning.

26 March 2022 journal

On February 2022, I fell in love with norns, a beautiful sound computer with open-source firmware and an open-source hardware version too named norns shield.
I checked the BOM and ordered everything from a couple of famous and trusted electronics component distributors. There were some problems because, if you remember, after COVID for a couple of years, there was a huge shortage of microchips, electronic components, and supply chains in general. This wasn't the best moment to get involved in a project like this, but I was really hyped, so I paid the extra cost for the standard components found and searched for valid alternatives for the sold-out ones on these websites.
Everything was ready except one. The audio codec Cirrus Logic CS4270 was sold-out everywhere! I only found it on the eBay from a private vendor for almost 10 times its original price! What a scam! But I decided to order it anyway...
After a couple of weeks, I have everything to start soldering.

I will be honest: it wasn't an easy task. Definitely far beyond all my previous projects, but I was very determined to achieve the goal, so I rolled up my sleeves and started with the easy ones: resistors, capacitors, audio jacks, buttons, and encoders.

The phase of soldering the crystal arrived. Probably my tools weren't the most suitable because it was very difficult to make the solder flow under the crystal (where the pads are located). Solder paste could have been a better choice. After the *CS4270 expensive version edition* was soldered, I checked all the pads with a magnifier lens to verify that there wasn't contact between legs.

The first problem was the connection between the screen and the main board. There was a 20 pins long connection on one side, and I found it very difficult to click inside. I applied too much pressure, and I broke the male pins.

Nanananana desolder time. The mistake I made was that I soldered it whit the long legs upside down. That's why I cannot insert them all the way into it. To prevent issues, I started plugging the stip inside the female pins and then I soldered the screen directly in place.

I connected the Raspberry pi and...

fcuk!
Time to debug. Firstly I troubleshot the hardware by checking the connection with a multimeter. Here is a topological connection I dit to power the shield and verify continuity and short circuit.

Since everything seemed ok on the hardware side, I started checking the software. I was able to connect via ssh to the norns, so I tried to find which were the problems. Some useful command line input for readers stuck in the same situation are:

# display startup messages
dmesg

# check the status of the service
systemctl status norns-jack.service

# display messages produced by the kernel about the norns-jack service
journalctl -u norns-jack.service

# kill and restart supercollider
killall sclang
sclang
0.exit
                

11 April 2022 journal

After some weeks, I received an alert from a trusted electronics store about the availability of the CS4270. I bought it instantly!
Now I just have to desolder the old one and place this one. But jeez, desolder at the same moment all these pads isn't an easy task for a n00b like me. I found this video where an option was to cut the legs and desolder them one by one. Seems viable. I tried it and made a mess (again)! I pressed too much with the cutter and destroyed a track.

I was so upset that I waited a year before writing this, but now I want to retry! I am writing this and, at the same time, placing orders to get all the materials I need to try again.
I can't wait to write a good happy ending for this story. So stay tuned!

June 2023 update: the follow-up of this post is online. Check it out here!