The Final Weeks Before LunchTrak's Launch

Guys, it's almost summer. There are only two weeks before it starts and there is still a lot I need to get done. I've been kinda stressed out lately with all my finals and LunchTrak stuff, and I really hope I can pull off this summer pilot.

Wake Up Receiver

First off, I'll give you (AKA future me) a quick rundown of what I've accomplished since my last post. I figured out the wake-up receiver matching with Andy and tested it out with Dave. The range is really good for a 30dbm gain. I have a 20dbm RF amplifier which gives about 2.5 meters wake-up range, but it is not practical. I'm currently waiting for my 30dbm amplifier to come on eBay.

PCBWay Assembly Order

Well, this is a mess...

I placed my order for my PCB assembly almost a month ago, and there have been many problems and obstacles since. The major one that's been keeping me up at night is the miscommunication between PCBWay and Siqore which almost shut down my entire project; I was told that the ATM2 Modules could not be shipped to Taiwan. My first thought was that it was because of the US-China chip wars, and I became really depressed for 5 minutes. I then looked up what the trade restrictions were and found that they only apply to high-performance chips, a rule which does not apply in my situation. After sending multiple emails and calling PCBWay a couple of times (thank God my dad knows Chinese because the lady did not understand me at all), I think the issue has been resolved. The part should ship to China in the next 2 days, which is much faster than the 20-day timeline I originally thought it would be.

Another big problem (and good learning experience I guess) is that my GND pin on the battery holder was not connected to anything. This is a big problem, and I would not have caught this if PCBWay did not send an email asking whether to put solder paste on the center of the battery holder pad. See the image below. Notice how the circle is not green?

The previous drawing did not connect the pin to GND, even though it looks like it should. Below is the corrected design, where you can see the green wire connecting the two pins.

I was literally so stressed because I thought that mistake would cause my board to ship past the deadline. Luckily, it didn't, and it only set me back $100. Imagine if the broken boards shipped and none of them worked...

The Case

This part is kinda fun.

Because we are not dealing with small 3D-printed batches anymore, the cost to print all 75 cases on JLCPCB is about $160. Crazy right? I'm sure that's probably cheaper than elsewhere, but that brings my product up $2 per part more than it should be, and would also cause me to exceed my budget. Luckily PAUSD included tax when they mailed the check, so I got an extra $75 to compensate for some other costs I did not account for (like how PCBWay charged extra for supplying parts).

Instead of paying JLCPCB to print them for me, and then wait 2 weeks for them to ship, I decided to do something more fun: I'd use the money that the school paid me to buy my own 3D printer, and then print the 75 cases with that. I ended up buying the Creality Ender S1 Pro, which is a great hobbyist printer that cost me $390 (on sale from $500). Yes, this is more than my budget, but I was able to split the cost after a kind investment from my sister. Basically, she would also be able to use the printer and she would be able to cash out 5% of my profits at any time she wants. Pretty good deal for me I would say, I got a 3D printer for free!

While it is cool to have my own 3D printer, there are some notable drawbacks. The print precision, for example, is much worse on my printer than on JLCPCB's printers. I think it is because they use resin, which gives smoother finishes.

I am also working on a new case design, which will give rounded edges and better text quality. I will probably change it multiple times, so it will likely not reflect the actual model used.

I also learned a little bit about 3D printing slicing with Cura. I am still not that good at it, but print quality seems to be good enough for now.

Update (20 minutes later as my print finished): There is a lot more friction in my home-printed cases than the ones from JLCPCB, so the lid gets stuck and it's hard to get out with the notch. Look what I did, I lowkey think I'm a genius.

The notch's functionality is changed from locking the lid in place to being a little handle to pull the lid off. Wow!

Bank and Money

I did it, I finally did it. After months of hard, sleepless nights, months of blood, sweat, and tears, I made $4 in profits.

Yeah... not a lot, but I wasn't planning on making money on this pilot anyways. Coincidentally, I actually said in my head before I worked out all the pricing, "Please God let me not be in debt with this pilot. I don't care about profits, even $4 would be fine". I think this is a sign.

Also, I think it is worth mentioning that American Express was the only place I could open a business checking account. The other banks require all shareholders with 25+% of the company to be over 18, except for Amex. Thanks!

Website Modifications

I made the website a little more user-friendly after (painfully) watching someone completely confused while trying to pair a LunchTrak tag. There was some confusion about the Bluetooth pairing popup, so I made it completely clear how to do it through a picture.

Typing the student ID number is fairly straightforward.

The last thing my friend was confused about was what to do at the last step. I added a verify button to confirm that they were finished!

Final Note

I'm scared guys. It's been a week and the PAUSD admin has not responded to my email about test-trialing the tags in the real lunch line. Could they have forgotten about my project? Are they ghosting me?

I had a really bad dream where the pilot failed miserably. The scanner missed almost every other person and people were complaining about how stupid the idea was. People even took apart the board and soldered weird stuff to it, throwing it away when they were done with it. Am I going insane?

It's midnight now and I should probably sleep. Good night everyone.