8-Bit Blog: IC Programming September 29 2013
There are many things that go smoothly during prototyping that fall apart when you begin manufacturing. We were in for a surprise when we recieved our first batch of programmed microcontrollers (or ICs). Below is a video of the sample IC that was sent to us by the programming factory. Note: this is not what it's supposed to sound like.
Unfortunately, they had already programmed 1500 boards this way, so it was time to take a trip out to the factory to see if we could sort it out. The reason we had let them go ahead without receiving a sample, is that they had made several versions of the board already, and we made some very minor changes in our last iteration (small tweaks to the sensitivity of the board). This was a mistake that we learned the hard way: If you change anything, even if it seems minor, make sure you get a sample before you begin mass production.
The IC programming house is actually a company that sells auto programmers. Their main business is in selling the machines to other factories, but they program ICs on the side to make some extra money. Below is a video of one of the machines in action.
Pretty cool, right? I've often seen microcontrollers shipped in those clear tubes, but never knew the reason why. Turns out they're very low resistance, so the chips can slide through them easily, even at a shallow angle. This makes it easier for machines like this one to robotically program the chips.
Another common packaging for microcontrollers is on a reel. This machine punctures through the plasitc casing with little spikes, and programs the chips with the same pins! Also pretty cool.
It turned out that our main problem was in the programming configuration. These are controlled by a group of settings called "fuses" that determine characteristics of the chip. The factory had turned on a fuse that caused the chip to run at 1/8th speed, which resulted in the lower tone that you heard in the video above. They were able to change the fuses, and make us a sample chip with the new configuration.
I've often found it very difficult to solder and de-solder ICs from boards (this is due to them having many connection points, which you have to heat up individually). At the programming house, they were pros at this. The engineer was able to take off our IC and solder on the new sample in a matter of seconds. When he was done, we tested the board, and confirmed that everything functioned correctly. Luckily they were able to reprogram the boards that had errors, and gave us an estimated delivery of two days.
After leaving the programming house, we stopped at a Szechuan Hot Pot restaurant. This was by far the spiciest meal we had, but it was absolutely delicious. Little did I know, there are distinctions between types of spice in China. The Hunan spice is what we more traditionally think of as spicy (think hot salsa). The Szechuan style of spice has a numbing effect, even in small quantities. This meant that every few bites, my tongue and other parts of my mouth would go tingly and then numb. It was a very strange feeling overall.
All in all, the programming error was a pretty good problem to have, and fairly easy to solve. It was one of many instances where I was glad to be onsite to help resolve the situation quickly, and without too much cost.
Thanks for reading!
8-Bit Blog: Silicone Secure Button September 28 2013
One of the interesting features of the Question Block Lamp, is that it hangs and receives power from the same USB cable. This poses some tricky challenges, as the cable needs to provide power to the circuit board, while also being anchored to the top of the lamp.
In order to solve this challenge, we created a custom silicone button that helps secure the cable, while at the same time allowing it to pass through the lamp to the board.
We visited the factory factory that makes the custom button for us, and they showed us the entire process. From the preparation of the silicone, to the molding, and final cleaning process (where they snip off any defects).
This is the first step where they take raw silicone, and use this machine to work out all the imperfections. The entire process takes about 5-7 minutes. This is the point where they would also add the dye.
Above is the process for making the silicone button. The mold produces 40 buttons every time they compress it, so it will only take a couple hours to produce all 3000 parts.
This is what the buttons look like after they've come out of the mold. They're fairly easy to pull apart by hand.
Because our run is fairly small (3000 pieces is minor leagues in China) two workers are able to get through all the buttons in a single afternoon. They'll remove the buttons from the excess material (also known as flashing), and check for any imperfections, which they'll remove with a small pair of scissors.
These are the two most common tools for working with silicone. The tool on the right helps workers pull the part from the flashing. The scissors on the left help them remove small defects.
The factory also had several other machines, including some fairly impressive injection molders. These will inject molten plastic into a mold under very high pressure. This is the process used for most of the plastic parts we see around the world. In the video above, you can see the production of glossy iPhone cases.
After visiting the factory, we went to a Maojia restaurant. This is a cuisine that originated in the hometown of Mao Zedong (top left), who was the Chairman of China from 1945 to 1978. He's also on much of the Chinese currency. Top right: Sticky rice covered beef balls. Bottom Left: Snow peas with bacon. Bottom Right: Pork soup with fried tofu and scrambled egg.
Thanks for tuning in folks! Next we'll visit the IC programming factory, after a bit of a mix-up with the code.
8-Bit Blog: Weekend Edition September 14 2013
We had a very productive first few days visiting factories, so I decided to take a trip on Saturday to Da Fen, a famous painting village in the northwest of Shenzhen. This is where much of the art in the region is produced, and many students come to train here.
This is Richard. He works for our sourcing group, and is an avid art enthusiast. He even came to Da Fen to train when he was younger, although he realized pretty quickly that it wasn't what he wanted to do for a career.
Richard and I walked through dozens of alleys and galleries admiring the brushwork of local painters. The area is quite large and we ended up getting lost pretty quickly. Neither of us minded though.
Almost all the painters were set up on the streets and in the alleys. Some of the best had spectators checking out their work. In these cases, I didn't feel so bad taking pictures.
We ended up seeing a slew of great artwork over the day. Unfortunately, most galleries and artists had a policy of no picture taking. So if you want to see more, I'd highly recommend taking a trip someday!
After spending the day walking around, we were pretty hungry, and stopped on the street for some cha shiu bao (known in the states as pork buns). These are warm pastries filled with sweet barbecued pork. They're often eaten for breakfast, but they're pretty delicious any time of day.
The next day was my birthday, and the sourcing team decided to take me out. In the morning we all went to play badminton, which seems to be a national sport. Everyone there was pretty skilled.
The arena we went to was huge, and had about 30-40 courts. The whole team was there, so we were able to play four at a time on two courts.
Richard and I squared off on a singles court before we left. I played tournament tennis growing up, so I was able to pick it up fairly quickly, but Richard is a verifiable pro (he's played several times a week for about 8 years). I did my best to keep up, but he was definitely taking it easy on me.
I didn't think very far ahead, and ended up wearing the worst possible shirt for a hot day of badminton (that line across the bottom isn't part of the design). We stopped at a sports store later so that I could pick up a shirt that wasn't drenched in sweat.
We all worked up a big appetite, and went to a local restaurant to relax and cool off. We ended up getting a private room (with an air conditioner!) and ate a fantastic meal.
Top left: sticky rice with pork bone. Top right: scrambled egg with red peppers.
Bottom left: fried potatoes served on a stone hot-plate. Bottom right: tofu and chicken with a soy glaze.
After lunch, the team brought out a birthday cake, which blew me away. The top was covered in mango and grapes, and the frosting was nice and light. Everyone had a pretty large piece, so we were all stuffed at the end of the meal.
Our private room had a Mahjong table, so we decided to play a few rounds after lunch. It took me a bit to learn the symbols, but I was decently competitive after a bit of practice. It's pretty similar to a game called Rummycube, which I played with my family when I was young.
Upon hearing the commotion, one of the ladies from another room came by to check out our game. She scrutinized our play, and tried her best to whip us into shape. I'm not sure we ever lived up to her expectations.
Overall, it was a great birthday, and a great weekend overall. Tomorrow it's back to work, visiting factories and figuring out assembly for the lamp. Good internet has been hard to find, so the next posts may be spaced out a bit.
Thanks for reading!
8-Bit Blog: China Edition (Day 3) September 13 2013
Greetings everyone! Day 3 here. As many of you know, the Question Block Lamp is controlled by a capacitive touch sensor. One of the toughest problems with a touch sensitive product is that the sensitivity can change with a variety of factors. This can include humidity, temperature, and skin conductivity (which is affected by oil or sweat). When designing and testing the lamp, we accounted for all of these, and made sure that everything would work under a variety of conditions. However, we didn't expect that the power supply might also have an effect.
Enter Mr. Yang. He runs a power supply factory here in Shenzhen, and has been working over the past several months with us to make sure our lamp will work in countries all over the world. We found initially that different voltages (e.g. 120V in the US, 240 in Europe) could have an effect on the sensitivity.
In order to solve for this, we needed a power supply that blocked any noise and interference that had an effect. Mr. Yang and his team of electrical engineers were able to help us figure out exactly what caused changes, and find a power supply that will work around the world.
Ever been curious how power supplies are made? I use them pretty much every day (to charge my cellphone and laptop) but had never actually seen their insides.
Well, the first step is to add all of the small surface mount components to the blank circuit boards. This is often done with a pick-and-place machine, which is a robot that very precisely and rapidly places all the components on a board. At Mr. Yang's factory, they have two pick-and-place variations that they use for their power supplies.
Larger components must be added by hand on an assembly line. These are then fed into an oven which cooks the solder and solidifies the connection.
These are stacks of completed power supplies. All that's left is to insert them into an injection molded case, and add an appropriate attachment. For our supplies this will be a USB slot. For many others, this will be a cable with a specified length.
Before leaving the factory, every adapter is run through a battery of tests that last several hours. This is conducted in a very hot room, to make sure that the supplies can function at high temperatures. The machines will automatically test each adapter, and display success and failure with LEDs.
After the factory visit, I met up with the hardware accelerator in Shenzhen, HAXLR8R (pronounced hack-sell-er-ate-er). We all went out to Karaoke nearby and had a pretty great time. Here's everyone rocking out to YMCA.
That's all for this week folks! This weekend I'm going to check out a famous painting village called Da Fen. Much of the art that's sold in Shenzhen and the surrounding areas comes from this village. Stay tuned!