Gangue,
I really wanted to finish the FDIM Buildathon kit well in advance of my drop dead date but that was not to be this year. March was a VERY busy month that compounded the typical workload that always comes up in April so I was working 20 hours a day 7 days a week all through April. I had several false starts with prototyping the Buildathon kit and when the 2 TTL chips actually did work, it was way TOO EASY! I built one on my Pocket Electronics Lab solder-less breadboards that fit inside a mint tin. It took me about 15 minutes and I was working hard to make it beautiful.... So I needed a little more oomph. I decided to throw in a Picaxe micro to the mix but seems like my Picaxe stock was low. While rooting around the web for Picaxe micros, I saw that they had eliminated the 14M2 and added its unique features to the 18M2. I didn't have any of those either but ordered some and included it in the design of the pcb. At the very last minute, I literally tripped over an obscure TTL submission in SPRAT that showed it in a transceiver configuration. Since I was still underway with the pcb layout, I just expanded the pcb from a 'regular' tuna board to a 'family' sized board to get the extra real estate. I knew we were only going to build the transmitter portion in the Buildathon but the extra stuff would be extra FUN for extended home work.... I try to advance the tuna legacy with each new design and I wanted to add the micro to make the first kit in my portfolio that didn't require a Morse code key to operate. I worked crazy hours to get the design done and then paid an extra premium to get them fabbed in 1 day! I still had the very uncertain shipping time from China so I had them shipped directly to the FDIM hotel. I never got to see the pcbs until I landed at the FDIM hotel late Wednesday night. I built up the first unit over Thursday and Friday, kitted up the parts and was ready to build by 3:00 on Friday. For years, we have started the Buildathon at 4pm on Friday with a pizza party around 4:45 or so to give people some time at the Hamvention before they had to leave and head for the hotel and the FDIM Buildathon. So I was sitting in my room at around 3:30 (or so) when there was a knock. I found Eric, KC2TXO, standing in the hall wondering where the head wrangler was for the Buildathon . Ther were a roomful of Builders that had been waiting for me to show up since 3pm! DAMN! a misprint in the FDIM schedule show the Buildathon starting at 3. News to me! So we grabbed all the stuff and took off.
There were 15 builders in attendance with 1 builder having to leave early due to his buddies having to be elswhere before he was finished. Out of 14 remaining builders, 13 were tested, fixed and declared GOOD! The last builder had a problem that we just couldn't diagnose. He changed several parts but we just couldn't get it to key. He went home with another kit to try a second build... Since I could only find 9 micros, the programming was incomplete and we only tested the builds using the direct keying from MK to MK which bypasses the micro altogether.
The GOOD:
As sold in the Buildathon buildup, the simple TTL 2-Chip Transmitter worked. The switched parallel output buffers indeed worked and created 4 distinct output power levels. There was a bypass capacitor between the 2 TTL chips that wouldn't fit between the 2 sockets but the problem was easily fixed by mounting the cap on the underside of the board and soldering the pins on the top layer before the sockets were installed. The MK-MK jumper worked as anticipated so the keying transistor circuit worked as desired. No power measurements were made but you could hear the distinct power levels on a nearby hand held receiver. The circuitry on board that made up the transmitter and control inputs to the non-existent micro-controller were just about right time-wise for the Buildathon.
The BAD:
I was going to come home and hop on the programming of the micro...but I also came home with a case of Covid-19! I felt like crap for almost 2 weeks...and I 'gave' it to my wife who was none too pleased! We have been hunkered down here at the farm for over 2 years! Masked up whenever we left the farm. She had both vaccine shots and both boosters. I was short only the 2nd booster. I rode 14 hours home with my buddy Steven, N1SH, and of course he got it too. He tested positive first and every time I talked with him, he sounded great. It hardly phased him at all. I think the Covid virus was afraid of my wife so her symptoms were practically non-existent but I felt like crap. I self isolated to a loft bedroom with a half bath, cleared off a table and set up my laptop and micro controller stuff. My main symptoms were that I was extremely tired and unable to focus long on anything...long with a completely saturated snot-locker and a raging sore throat. I tried to get things done but I only had short spurts of energy and really couldn't concentrate on anything very long....and that bed looked so enticing!! So now much was accomplished for about 2 weeks.
The ENCOURAGING:
The micro programming has advanced quite nicely over the last week or so. The control options section and direct keying section have been written, debugged and now working fine. I wrote the keyboard to Morse routines but have spent the last few days trouble shooting problems with them both in hardware and software. I had assumed the PS2 keyboards were I^2C serial devices but turns out they are NOT! So I had connected the keyboard lines to the I^2C pins which I only discovered yesterday was the problem. I'm moving them to the actual specifically defined keyboard input I/O pins and hope to have the PS2 keyboard working fully tomorrow. Then I'll be on easy street. I could only buy 9 micros before Dayton and since the programming wasn't even started, nobody got micros. Nobody got receiver section parts either. I have ordered more micros and will hopefully have all the remaining parts in house by Monday at the latest. Kits and parts bags will go out to everybody very early next week.
I'll put together a couple of sheets of build/modify instructions and post those after I ship the remaining parts.
Sorry for the big delay but unforeseen forces were at work and threw a giant Monkee's wrench into MY plans...
Rex? W1REX
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