CE for Babies August Update

Books have Arrived!

Tldr: The Computer Engineering for Babies books finally showed up and are starting to to ship out. There are a lot of orders, so if you don't get a tracking number in the next week, it's not because I have forgotten about you. But please click the button and confirm I have your shipping address correct (if it looks good, no action is needed), and if you're outside the US you'll need to add a phone number that I can put on the package label. And I have about 10% extra books, so if you want to add a book to your order you can do that as well:


The dirty details of the last month:

I was expecting that the books were going to show up two weeks ago. With the couple previous batches of books, the boat would arrive in the US, and then three days later the books would show up on my driveway without any warning. This time, however, it took a couple weeks between the boat landing in the US and the books showing up to my door (actually this time it was a storage unit). But the books arrived yesterday! With previous batches, the boxes would arrive with six guys to unload them off the truck and stack them on my porch and driveway. This time they gave me a scare, while I was away visiting a friend. The truck showed up to the storage unit, and there weren't six guys, but one tired truck driver with a bad back. Shortly after, I got a call from their boss threatening that if I didn't get some people over there to unload the truck within the hour, they were going to take off back to LA. Fortunately, after anxiously pacing in circles for 30 minutes, I was able to recruit a couple friends to show up with only a moments notice, and they got everything quickly unloaded.

There is one other hiccup, which I have been fearing the last 6 months, that was realized a few weeks ago. The program that runs on the circuit board for these books has some problems and all the chips need to be reprogrammed one by one, AGAIN! This, so far, has happened with every batch of books that I have received. Let me explain why this happens and what it means: to detect which page is open, there are holes in the pages that expose light sensors in the back of the book. The circuit board runs code on a microcontroller and takes readings from these light sensors, and then predicts which page is open on the book. Well, whenever I make a change to the book or the circuit board, the code on the chip usually needs to be updated as well. On this run of books, I moved the light sensors to the top of the page, I've changed some of the components on the circuit board so it can work in both darker and brighter environments, and I was forced to swap microcontrollers, due to the the previous chip not being available anywhere (chip shortage).

I had three sample books to test my code on, and everything was working great with the sample books. Then we scaled it up to thousands of books, and after the books had already shipped, I start getting messages about books with lights that aren't turning off, and it becomes clear that the code hasn't scaled well. There is variance from book to book in the amount of light that leaks through to the sensors, and some of the books are getting confused about which page is open. I had a box of the problem books air mailed to me, and I received them 2-3 weeks ago, and I have fixed all the code so that they don't get so confused, and been able to test and confirm that we're in business. It now seems like an obvious and stupid mistake to make, but my lesson has been learned: three books is not enough to confirm that the entire batch is going to follow suit.

So now I need to flash all the books in this storage unit with the new code files. At scale, this takes about 20 seconds for each book: open the window on the back cover to expose the programming pads, reprogram, and then re-seal the back window. This is a lot considering that it takes about the same amount of time to construct a shipping box, put the book in it, fill the void space with glitter, tape up the box, and put the shipping label on it (Just kidding about the glitter. Imagine how awful that would be). So this adds to the amount of time it takes to get a book out the door, but we've cleared out our living room so we can have a few more people over to help get it all done.

The next email you get will be "Your book(s) are shipping." which will be a last call to update your order/address, and then you'll get an email a few days later with a tracking number! Thanks again! Feel free to email me with any questions or concerns.