2020-08-24

We went out for brunch today, and my daugther who has been sick the last week and not always eating or drinking enough, devoured her food and even ate all the bananas and blueberries off my plate. She even drank some of my orange juice, and appeared to enjoy it. We were relieved, and we look forward for her to go back to daycare.

I also had two packages arrive today, and I was looking forward to testing components and assembling the case for my component tester. Unfortunately the mounting holes for the case were off, so I need to drill the holes so that I can shift the component tester a few millimetres, and hopefully assemble the case without pinching or squeezing everything to fit.

Then I tested the transistors I ordered for an auto shutdown switch. These were for alternative that I could build with through hole parts, in case the SMD soldering for the first choice ends in disaster. They were supposed to be P-Channel MOSFETs (Normally Open), but the parts I received are actually N-Channel MOSFETs (Normally Closed). The label on the transistors are correct, but component tester and an independent test using my multimeter indicated that they are mislabelled.

I think this is the first time that has happened. Two nights ago I would have said that it has happened to me twice, but I realized that I was in error. I thought that the OLED display I purchased was supposed to be 128x64 pixels, but I could only ever get the 128x32 pixels version of some Adafruit code to work with it. I came across a few arcade games recently that fit onto an ATtiny85 using an 128x64 OLED. I wanted to try them out, but I thought the only display I had was too small. While searching for other versions of the display, I came across a forum post mentioning my exact situation. The author mentioned their realization, that he just had to set the number of rows to 64 instead of 32 and it worked. I decided to check my display using the Adafruit library, and I was able to get the 128x32 version working. When I tried the 128x64 version, the display did not work. Then I realized that the two demo codes used a different I2C address, so when I changed the 128x64 version to use the working I2C address the 128x64 version now worked! So I was able to resolve an old problem.

It seems that the code that connect to the incorrect I2C address, does not fail as I would expect it would because I did not see an error message in the serial monitor. If that code had displayed an error, I may have spotted the address mismatch sooner.

I also ordered some LiPo charging boards, and two HC-05 Bluetooth Serial boards. The charging boards all appeared to work, providing the correct voltage. When I tested the new HC-05 boards, initially they did not work. I tried swapping the RX and TX pins on the Arduino, and I was then able to get messages from my phone sent to the boards. When I re-connected the original HC-05 board I was still not able to receive a message, so it seems I might have damaged it.


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