After comparing the new solder joints to the ones I was making with
the old iron, I decided to start completely over with the LED Binary
Calculator. This time I used DIP sockets and new protoboard I was able
to buy when I bought the new soldering stuff. This protoboard is 25
holes wide which is really convenient since each of the eight LEDs needs
three holes width. There were also just enough of the old red LEDs I
was using before to start over with. The solder didn't take to them very
well at the beginning so I had to scrape off a lot of the coating that
had formed on it. Because I didn't have a battery holder, I soldered on
an 8 pin DIP socket to use as a power connector. I taped wires to a
CR2032 battery and I stick the ends into the socket for power.
After
soldering everything together I ran a test of the LEDs. They only
worked correctly once and the only way to get them to work again was to
remove both the shift register controlling the LEDs and the MSP430.
Toggling the master reset of the shift register didn't help either. Upon
closer inspection it turned out the ground connection to the MSP430 had
come loose. I was surprised that it ran at all with no ground
connection but I have seen it do something similar on a breadboard too.
The buttons worked fine from the beginning except that two of them were
linked by a solder bridge. After I fixed that, the whole calculator
worked as expected.
