Make: Electronics... a book review and BLOG

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2 phunni. many are wondering if the rfID chip is just that:

rfid-chip-obamacare.png
 
Make Electronics: Experiment 18: Make a Reaction Timer... Continued

OK, I got stuck again. The next step in this reaction timer was to add another 555 timer to be able to interrupt the 4026 decade counter. It was actually straight forward enough, but I got in the way. I go tin the way and I got busy enough that I couldn't stop to suss it all out. I don't mind busy. It's great to have friends over and to be able to fellowship and connect face to face instead of merely over the interwebs. I learn a lot and get to do dives I normally wouldn't do. I put this next step in just under a week ago and thought I knew what was going on. I didn't. I thought the driving pin was going to pin 2 of the 555 timer and for the life of me I couldn't figure out how it would work and in the end I was right: it wouldn't and didn't work. I kept wanting to go back to it, but life got in the way. Yesterday was a pretty frustrating day... I had to go into Miami for some Scuba stuff and it seemed that everything and everyone was conspiring against me. There was stuff happening at the house that contributed to the whole mess as well. I walked past the electronics bench a number of times and the circuit just sat there mocking me. However, I opened up the Kindle Book last night and started reviewing schematics again. I looked long and hard at the 555 timer that was set to generate a pulse to the decade counter/decoder. You know, when I took the switch out that I put in I don't think I replaced that positive jumper to pin 8. Now that I thought of it, maybe instead of going to pin 2, the second 555 needed to drive pin 8, but there was a typo? I popped back over to the second 555 schematic and my problem hit me in the face like a wet tuna. It said to connect pin 3 to pin 2 of the 4026 and not the 555. ARRRRGGGGGGHHHHHHHHHHH! It didn't specify which one of the three, but I was certain it was the last one I wired in. I was up at 5:30 this am, took out the trash and went over to the electronics bench. Even though my Kindle was upstairs, I remembered what I wanted to do. I first connected to pin 2 of the 4026 and then I sent power to pin 8 of the first 555. Bingo! Yahtzee! The circuit works as advertised. I'm not finished with this project yet though. I still have another 555 timer to wire in. Maybe I'll have time today.

This is a problem with communications. No, the book didn't have the problem: I did. I anticipated where that 3rd pin was supposed to hook into rather than reading it with an open and clear mind. I was trying to sneak this circuit in between obligations which is not the best way to learn anything, much less something technical.
 
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Do you understand what are you wiring together or you just follow some scheme ?
I make sure I understand the logic behind what I'm doing. That's the whole point. I think the best evidence that someone understands something is that they can troubleshoot it. If you didn't understand it before, you do afterwards. I am still trying to suss out the last part of this experiment. I'm not there yet, though the circuit seems to be working. My mind is not comprehending the role of the last 555 I just put in. Once I "own" it, I'll be posting what I learned.
 
https://www.shearwater.com/products/perdix-ai/

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