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enter the chamoun zone
this blog will likely be about project progress but i will also likely talk about other stuff like big events or other interests i have.
for science;adventure stuff, check out the sci;adv quick link.
7/1/2024: after lots of thread searching on microchip's website, using the EEPROM non volatile memory is actually really easy. all that needed to be done was add __eeprom to the global variables that i will be storing whenever the clock shuts down. overall lots of progress, but still lots of ways to go in terms of programming the rtc. i have capabilities for two time of day alarms, but im wondering if this is overkill or not. what ill probably do is make the clock do an animation based on one alarm because the ds3231 has an internal timer, meaning it can activate a specific function every 2 minutes or so which would be cool for the clock animations to help prevent nixie tube cathode poisoning and help longevity. the other alarm will be the stereotypical sound alarm, so i actually only need 1 byte of eeprom memory for this specific alarm as everything else is calculated directly from the ds3231 rtc chip;
6/26/2024: spent the day reading the datasheet and figuring out how the interrupts and PWM works. I gotta say Microchip does their datasheets very nicely and I am a big fan. big shoutout to this guy: https://www.youtube.com/watch?v=OLYNW1EL0e4 for teaching me a lot about the interrupt flags because it saved me a ton of time. i just ordered the pcb from jlcpcb so hopefully we can begin prototyping stuff soon. update on the hvps, a new one from aliexpress arrived today and is confirmed functional. unfortunately, the two other nixies are confirmed broken, so ill eventually have to order 2-3 new ones. finally, i need to order some solder paste and a small hot plate off amazon tomrrow, should be pretty smooth. tomorrow lots of homework to catch up on, but i am very happy with today's progress B];
6/25/2024: forgot to order connector for pcb parts, luckily have not ordered yet. sometimes my anxiety pays off i guess ***and saves lots of shipping fees. gerber is good to go, ill order it when i submit my parts order first thing tomorrow. then i have class and some more hw to be doing, but after that i can look at potentially getting a hot plate or reflow oven. i think hot plate it is, but ive heard stories of people making their own reflow ovens for cheap using an old oven, so ill check ebay and facebook marketplace before ordering i guess;
6/24/2024: fixed orientation error i made with the second layer. i initially designed the first layer to be oriented upside down so all chips would face downward. this allows a cover to be placed without messing with any data lines outside of some throughhole components such as resistors. need to finalize things still, but everything is checking out. once pcbway approves it i will order the rest of the parts as well as the pcb. i also added some pull up and pull down resistors which i forgot to add for the inputs and the rtc interrupt pin. i think im good to go so i am just going to generate the gerbers first thing tomorrow an if any errors occur i will just order a new board with fixes. there is bound to be at least one error so no point in worrying too much about it right now. all the mounting holes line up now when the first layer is flipped over, so yes, ill do a quick check tomorrow, maybe get rid of unnecessary ground lines from both layers, and get it sent over. thank you man on youtube who helped explain the rtc datasheet because microchips documentation left some unexplained details;
6/23/2024: "finished second layer. need to finalize both first and second: double checking everything looks right, double check pwm pins, add ground plane, and finally send to pcbway. im kinda slow but hopefully done with first version pcb by tomorrow.";
6/22/2024: first layer of pcb design is done but still need to redo some of the traces to make it the most efficient and to prevent any voltage creeping. I confirmed that pcbway allows 4.0 mm holes, with 4.5 mm diameter vias;
6/20/2024: having concerns with my high power traces as i need to have clearances within a specific range, i think it is around .50mm... tomorrow ill set up the net class so i can ensure these constraints are met, and i should also remember to route along the whole board and to use all of the space as i think i have been trying to conserve space when i should be ensuring that all of my constraints are met instead. good progress today though for sure, just need to ensure everything checks out before sending stuff to pcbway;
6/19/2024: finally finished some more hw. glad to be working on the pcb again. today i added some test points as recommended by a youtube video to help when desoldering nixie tubes (it sucks to desolder th 8pin throughholes) as well as figured out the polarity feature on the logic converters. the clock will have 4 buttons: minute button, hour button, clock button, and alarm button. hold the clock button and select hour/minutes to change that, hold the alarm to change the alarm activation time. this is modeled after my childhood spongebob clock :] iykyk. it will also have a mode switch: DM mode, clock mode (no alarm), clock mode (alarm). tomorrow i hope to finish assigning some footprints, and get started on designing the 2-layer pcb (this will likely take most of my time relative to everything else i have done so far);
6/16/2024: life is good, more progress on pcb including adding schematics for a buck converter which will allow 12v to go to 3.3 v. instead of applying every day, every other day works better as it has come to a point where I have already applied to the ones from the day before and they keep showing up on the job boards i frequent. tomorrow, more work on schematics for the hvps logic converters, then i will probably look into a sound module for when the alarm sounds;
6/11/2024: a complete 180 with my clock, i am choosing a different mcu, as the one i had initally picked the PIC16F877A does not allow for i2c and spi communication simultaneously. this is why it is so important to READ THE DATASHEETS oooooo , crazy ikr... now im going with a new MCU which allows for SPI and I2C at the same time which I need in order to 1: communicate with the RTC, and 2: play audio from SD card. I hope there are some libraries I can use for MPLAB X IDE regarding playing audio from an SD card for my specific MCU, because it is a slightly less popular mcu than my original pick. HOPEFULLY it will work (if there are even libraries to begin with). previously there have been a lot of arduino libraries that lacked documentation, but they were there nonetheless. hoping for the best;
6/10/2024: life is a grind at this point which i love, pcb progress is happening, maybe like 1 module per week would be a good goal? i need to remember to add mp3 sound support for an alarm or something which may require an sd card for mp3 data but we will see. first day of summer instruction went well, it is a daily thing for me just have to stay motivated and not burnout. definitely lowering the amount of daily leetcodes and pcb designing i am doing, because accelerated summer classes WILL take a toll if i dont chill out in my downtime. job apps 10 a day is the goal but honestly days off are toooootally fine to avoid any burnout but it is good to have that goal out there. i will remain humble and keep it up tho orz;
6/9/2024: lots of progress regarding whats going on the pcb... i finally understand what i need for the rtc, chose my MCU, one of the PIC's (i need more practice with microchip's chips because they will always be in the industry is kind of my logic), and tomorrow hopefully i will add schematics. need to take a break from all of this as my last class of college in the summer begins tomorrow, but i will continue this project whenever i have time throughout the summer semester. it is important to not burn out!!! so i am really going to be taking baby step with this project. regarding the whole power supply issue from the past two days, that i still present so i will likely just order a new module so i can be at 170V. kind of a pay to win solution but in the case i fix it affter replacing capacitors or resistors, im sure i will use it in a future project whether it is making another clock, replacement parts, or nixie tube designs (maybe a watch?) that is all for today;
6/8/2024: i reread everything again but R_adjust still does nothing to impact the output voltage, im still at 150v when i need to be higher. I emailed the manufacturer of the chip and he responded really quickly telling me to reflow the joint. Unfortunately that did not work so I have replied with a picture of my test setup, so hopefully he can help me through this annoying bug. Not too much progress today as I take a short day break from leetcode, but I did start the KiCad project. I will almost certainly be using MPxIDE instead of Arudino because the libraries that Arduino uses really lacks any documentationfrom my experience. tomorrow ill progress in the KiCad schematics so I can get my first prototype ordered(focus on the RTC module);
6/7/2024: tested all of the nixies on 150V. all but two worked, i think due to me not using the proper voltage of 170V. one of the 8 tubes i have has a very short lead, so im considering just buying a new set of 6 or something (also good to have replacements handy). tomorrow i will test on 170v after i reread the datasheet, then ill begin my pcb work after ensuring i have all the nixie tubes ready. Postnote: after playing some games with friends it has come to my attention that R_adjust needs to be set to something like 50-100kohms (read the datasheets closely in the future!);
6/6/2024: i restarted my clock project because there were too many bugs when i built it initially due to beginner mistakes but now that i have more experience under my belt it should be good to go! i got all of the in-14 nixie tubes unsoldered which was a whole process but tomorrow i will work on getting the high voltage power supply unsoldered as well to begin testing on a protoboard. eventually alligator clips would be nice especially when using high amounts of voltage. Sidenote, ill have to order at least one more tube but that is for later. join me on my journey to complete the clock;