In one hand you hold the soldering iron, in the other the solder, and in two more hands the parts you’re trying to solder together. Clearly this is a case where helping hands could be useful.
One reason is to take advantage of standardized, open source creativity. Anyone can share a model of their design for all to use as is, or to modify for their needs. A case in point is the ball and socket model which I downloaded for a helping hand. I then drew up and printed a magnifying glass holder with a matching socket, made a variation of the ball and socket joint, and came up with a magnetic holder with matching ball. Let’s take look at what worked well and what didn’t.
Our guests for this week’s Hack Chat are Pete Dokter and Toni Klopfenstein of SparkFun Electronics. Pete is formerly the Director of Engineering at SparkFun and now the Brand Ambassador for SparkFun Electronics.
He hosts the According to Pete video series expounding on various engineering principles and seriously needs a silverburst Les Paul and a Sunn Model T. Toni is currently the product development manager at SparkFun. She’s served on the Open Source Hardware Association Board and participates in the Open Hardware Summit yearly. In her free time, she spends fifty weeks out of the year finding dust in her art and electronics projects.
The Micro:bit is a pretty decent platform for teaching kids to program, but you can’t really make arcade-style games for it. You only have two buttons and a 5×5 display. Perhaps enough for a very small snake game, but that’s pretty much it. That’s why I started working on #PewPew FeatherWing as an alternative platform, but at some point I started wondering if it’s really impossible to do it on the micro:bit.
When the most recent version of micropython got the ability to use any pins for I2C, I realized that I can finally connect a display easily. I could use a HT16K33 and a 8×8 LED matrix like on the PewPew, but I decided to try something else — a monochrome OLED display, similar to the one used on many Arduino-based game consoles.
This project is based on my #reDOT project. Basicly it is a 5×7 SMD LED Matrix an a microcontroller on one PCB. I started wirh 0201 LEDs (see first project log), but this was not reliable. So a second version with 0402 is in development. 0402 LEDs do have some benefits over 0201:
bigger and you can solder them better
cheaper
more colors availible
The microcontroller (a low coast STM8) drives all LEDs directly with multiplexing. For controlling a UART interface is available. The dimensions are like a DIP-6 package. For easy connection of multiple PCBs, the pads are castellated. Also the supply rails are available on both sides. So multiple of these display can be soldered together to a bigger display without the need of additional wiring.
This is a small blinky with 20 LEDs powered by one CR2032 coin cell
and with an ATTiny45 brain. The firmware is written in plain C and
compiled with the avr-gcc toolchain. The PCB is a two layer design made
with KiCad.
The Snowbot has three major subsystems: Power and Timer and Display.
Power Subsystem
The power subsystem uses a 3.7V LiPO battery boosted to 5V with an SC4503 boost converter to power the fully analog circuit. It requires a set of passive components in order to generate the higher voltage.
Timer Subsystem
The timer subsystem is comprised of a 555 IC that generates a clock signal. The speed of the clock is adjusted by twisting the potentiometer (the nose of the snowbot). The clock signal ticks through the outputs of a CD4017 decade counter, lighting each LED in sequence, then moving back through them again.
Display Subsystem
The display subsystem involves taking the output of the CD4017, and directing it to six red LEDs in the form of a larson scanner. In addition to lighting the LED, the current also charges a 22uF capacitor through a diode. When the output moves to the next LED, the cap discharges through a 2.2K resistor (part of a resistor network), fading the LED out gracefully.
Makernet Knob’s makes the point that “Rotary encoders are cool but hard to wire into your projects.” Having wired up a custom input device for my computer using an encoder, I can attest to both of these statements. In my case, it took me quite a bit of time simply to figure out how each encoder pin was used!
Three years ago, as a student under the Google Summer of Code program for BeagleBoard.org, I developed BeagleLogic – that turned the BeagleBone Black and its variants into a Logic Analyzer using the Programmable Real-Time Units (PRUs) on the AM335x SoC to capture up to 14 inputs up to 100 MSamples/sec. It is possible to fill up to 300MB of the 512MB DDR RAM in the BeagleBone with logic samples – that’s 3 seconds of data at 8 channels (1.5 secs at 16 channels). I also designed a cape for the system – called the BeagleLogic cape that would allow buffering the external logic signals up to 5V TTL so that they do not damage the BeagleBone.
The launch of Octavo Systems and its OSD3358 SiP got me excited, and the idea of a turnkey version of BeagleLogic was rekindled as the design would be greatly simplified due to the SiP integrating the core components, leaving me to focus on the features I want to add to the system.
From concept to completion, this project took 4 months working on it part-time. I relocated in August so work happened at an even slower pace during that month
The schematics were originally based on the OSD3358, however Jason encouraged me to design based on the newly announced OSD3358-SM as it was smaller and had a more optimized ballmap. The schematics were then migrated to the OSD3358-SM in late July. At the beginning of the routing exercise, I was really apprehensive if the design could be routed in 4 layers but thanks to the optimized ball map of the OSD3358-SM, the routing was easily completed so.
Reflowduino is the first completely open-source, Arduino-compatible reflow oven controller of its kind that enables practically anyone to assemble their own beautiful circuit boards at home!
Reflowduino comes loaded with features, all in a compact Arduino-compatible package, with full documentation, example code, demo app, and comprehensive wiki on Github.
Reflowduino is designed to be extremely easy to use! The general concept is to switch the power of the appliance on or off with a solid-state relay as shown below, measuring the temperature by placing the thermocouple tip inside the oven during the whole process.
If nothing else, please share this campaign to your friends, family, and anyone who might be interested on social media! Remember that every view counts for me, and I’m depending on you to make this happen!
OSH Park 