Weekly Update: May 27, 2017

So, this one’s a bit late. I apologize. It’s been a long weekend at my primary job and it’s worn me out.

On the plus side, that’s now over, AND I have three days off this week. Once my DigiKey order arrives, I’ll be able to hop into some more testing. And speaking of testing – A major landmark in this past week! I managed to upload code to the ESP-12 on the new board. It looks a bit funky, as I had to horridly cobble on some headers into places where they were never designed to be in order to bypass the CP2102 chip, but it worked.

Look at those horridly-cobbled-on headers!I also soldered on the SD card slot, and that worked mostly flawlessly too. The test program picked up the SD card and files just fine, and while a separate one didn’t I’m not too bothered. The SD card is also much easier to remove, unlike the first prototype where it was incredibly difficult. As you can see, it’ll have to be moved to the side some to allow for proper access to the mount hole, but that’s a minor issue.

However, I ran across two issues when attempting to put the rest of the devices on the badge: One, I forgot to order the 1% resistors for the buttons (Oops…), and two: It now isn’t uploading any more programming. I’m not entirely sure at which point the uploading failed, so I’ll have to go back through step by step and test things as I go to see where things went wrong.

Additionally, I discovered an issue in the way the voltage regulator(s) were set up. While they seemed to be functioning (I only managed to test the USB regulator), they wouldn’t stay on even when the ESP was programmed to keep them on. So I’ve begun looking at ways around this issue. Currently, I’m poking through a design that uses an ATTiny running directly off of the battery or USB power (Yay diodes!). The ATTiny can be run as an I2C slave, meaning no extra pin usage on the ESP-12 – In fact, what would have been the power line would now be a free GPIO line. I’ve done some testing with the ATTiny85V that I have and it looks good so far. The ATTiny85V has just barely the number of wires I would need, though, and for curiosity’s sake I looked into the ATTiny84. The 84A has 11 I/O pins to the 85V’s 5, and was actually slightly cheaper on DigiKey. I sent a request to the PCB Manufacturer to get the price of the 84 to see if they can acquire it at a similar price. Additionally, if I use the 84, I could potentially drop the digital potentiometer and drive the backlights from the 84. The digital potentiometer isn’t extremely expensive, but being able to offset the additional price of the 84 some would be great.

I have a DigiKey order that I’m waiting on that has a few 84s to experiment with along with the 1% resistors. I’ll be designing a new PCB to get prototypes of once I have a few more things figured out and adjusted, as there are a handful of things that didn’t line up on their footprints quite so nicely.

If you want to yell at me for being extremely late with this update, you can find me on Discord, on Twitter, and/or Facebook.

Weekly Update: May 20, 2017


I did this:

My reflow oven isn’t the best, so running it on the automatic settings generally doesn’t work. Putting it on manual typically works like a charm. Unless you set it to heat, step out of the room, and get distracted. I think the thing was well over 300C, probably 350C, before I caught it. As you can see, that’s well beyond rated temperatures. Also, it smelled. Oh boy, did it smell.

Anyway, that was the first test of the V3 Prototype 2 board. Getting the CP2102 soldered on correctly is being a complete bear, so I’m likely to bypass it for the next test, just to make sure everything else is working correctly. I only have one more ESP8266 module not attached to something, so if I fry this one I’ll have to wait until Monday when more arrive.

Honestly, at this point, the biggest holdup is the CP2102. Getting it to solder properly has been a bear. I have a new, fine-point tip ordered for my soldering iron that may help with any bridges that form, but as long as I can get the device itself working, I’m less concerned about the UART bridge. Thankfully, the minimal equipment to test is, well, very minimal – A handful of resistors, two transistors, and the ESP12 module. That’s enough to make sure the ESP’s wired correctly, and once that is confirmed I can go from there.

Now that I have the boards, I’ll be back to prototyping and testing, and I expect a more substantial update next week. You can find me on Discord, on Twitter, and/or Facebook before then.

Weekly Update: May 13, 2017

Updates, updates, updates!

Last week I mentioned the project I was working on for the lightsaber interior. I can happily say that they are all assembled, tested, and working and will be shipped out soon. Look, I even have a picture!

I managed to impress myself with this one, as usually there’s at least one device that needs to be fixed or tweaked to make it work. These guys all worked like a charm, first time. Granted, they’re super simple, consisting of an ATTiny85, a 10k ohm resistor, and a MOSFET, but I’ve learned to never underestimate my ability to make some stupid mistake and put something in backwards.

The test PCBs for the V3 won’t be here until Monday, and given the way things are going that means I probably won’t be able to touch them until Wednesday. I’ve been busy at my regular job (I don’t recommend working in a grocery store during the holidays… and there are a lot more of them than you think), so haven’t had a chance to really fiddle with the code much either.

So instead, I want to talk about the next product I want to develop, once I have the funds and the V3 is finished. It’ll take a significant amount of time to work out, but I’ll be able to work off of the V3 as a base to get it working a lot quicker. It’s also something that Michael (Who I made the ATTiny/MOSFET boards for) has been prodding me for a while to make.

What is it? Why, a tricorder! To be fair, it’s not actually a tricorder from Star Trek, but it is along similar lines. Simply put, I’m going to be taking as many sensors as I can get my hands on and jamming them into a single handheld device. An accelerometer, magnetometer (AKA, a compass), GPS unit, temperature and humidity, barometric pressure, a variety of gas detection sensors, distance measurements… While this list includes a number of things I want to include, it doesn’t include everything. And just because something is on this list doesn’t mean it’ll be on the final board. I do intend on having some designated expansion slots on the device as well, as there are some things that are simply too expensive to include in a base device. Take, for example, the LinkSprite JPEG Color Camera – It can output to an RCA display, and can also take JPEG pictures. Incidentally, the ESP8266 can display JPEG pictures, allowing it to display directly the images this camera takes. It’d be a cool addition, but not worthy of adding $50 to the pricetag. On the other hand, if someone wants to add it to their device, that’s  great!

I’ll be back to talking about the V3 next week. You can ask me questions about the V3, the ATTiny/MOSFET, the tricorder, or any number of things on Discord, on Twitter, and/or Facebook! See you next week!

Weekly Update: May 6, 2017

Greetings, everyone, and welcome back!

This week, we have a handful of things to talk about. I did the “last” testing required to get the V3 design to where I could send it off to get another set of prototypes printed. I also worked a little on the code, getting the badge code and Pride Flag code functioning. I still have to re-implement image and slideshow modes, along with rebuilding the menu system, but that can take some time to be done. I also am having issues with GPIO0 on this device, but even with those issues I can still upload code so I’m not terribly worried. Just annoyed. Hopefully those PCBs, along with the others, won’t take terribly long to get here so I can start testing them out.

On Sunday I mentioned a secondary project. This one requires a little bit of explanation, since while it’s a simple device, it’s incredibly specific in its purpose and design. My friend Michael is part of the Golden Gate Knights, a group of Star Wars Lightsaber enthusiasts who train in the proper methods of saber combat and stage choreography. Michael is working on a saber for a friend of his, and wants to introduce a slight flicker to the blade. These blades aren’t your typical saber blades, because as mentioned in their web page, blades with LEDs going their whole length tend to have LEDs die under repeated impact. Instead, they use high-powered LEDs at the hilt – Enough to require a heatsink and a significant power supply.

So, while the requirement was fairly straightforward – Apply PWM to the feed of one of the LEDs – the power required made it outside of almost all “Standard” approaches. To that end, he contacted me, seeing if I had any input. My design was fairly simple – As the LED uses close to 3v of power, I can hijack that to run an ATTiny85. The ATTiny then runs its PWM output to a MOSFET, which controls the LED. I ordered the parts to prototype it, confirmed the design worked, and then sent off for the PCBs. The device is super simple – ATTiny85, a 10k resistor, and a MOSFET, along with programming pins, power pins, and LED pins. This device won’t be on the store soon, as the V3 is taking priority funding, but it’ll be there eventually. I have a bunch of ideas for saber bits and bobs that I’ve tossed back and forth with Michael, so don’t be surprised if something else shows up, too. If you have any ideas, feel free to toss them out. And, if you want something custom built, I’m completely down for that as well. It’s not always cheap – Michael purchased the entire production run – but I’m willing to work with you to see what we can build. Especially if I can sell it later.

That’s all for now. As always, you can hit us up on Discord, on Twitter, and/or  Facebook!