Macrofab Engineering Podcast

Podcast Notes Stephen and Parker do a live discussion on how the digital and analog side of the Super Simple Power Supply will interface with each other. MultiSim has been a huge part in simulating the power supply design. Stephen has a new blog post about the Super Simple Power Supply. Parker has the 3D layout of the Super Simple Power Supply and the FX Dev board enclosure done. He still needs to draw up the mechanical drawing to send off to the machine shop. See Figure 1 for the 3D layout. Stephen built a discrete opamp built into a standard DIP-8 package. The opamp is designed for audio applications and Stephen wants to build a guitar effect pedal with them. See Figure 2 for the board. Parker wants to try to build a discrete 555 timer inspired from Stephen's opamp. Smallest BJT Parker can find is the 2SCR523V1T2L which is a DFN style package with a physical size is 0.8mm x 0.6mm x 0.35mm. Microchip publishes USB Mass Storage Loader that allows programing PICs by dropping the .HEX file into a "thumb drive

Parker has almost finalized the front panel design for the Super Simple Power Supply. Going to have a "VU" meter for how much power it is pulling. Parker is also still looking for a proper encoder that is vertical mounted but is also thin enough to squeeze between the PCB and the aluminum front panel. Next week Stephen and Parker will do a "live" discussion on how the Analog and Digital side of the SSPS will mesh. Stephen is working on a Ultimate Pogo Pin Showdown article for the blog. He will be testing lots of different kinds of pogo pins with a wide assortment of tests. Parker is working on getting an enclosure for the FX Dev board completed and Stephen has REV 2 of the PCB being made. MacroFab now supports ODB++ format. Most big EDA tools support this format. No Eagle ULP for ODB++ format? Article on the EEWeb about "Why to like USB 3.1". Parker thinks the article is total click bait. Stephen thinks its USB 3.1 is not backwards compatible if you have to use an adapter. Any reason to still use through ho

Podcast Notes Parker is still working on the Super Simple Power Supply. He is designing the front panel. He is considering using some WP1043 Kingbright LEDs. Super Simple Power Supply will have two decimal places for the LED segmented displays. 10mV and 10mA display resolution. Keypad for punching in numbers directly and encoder for scrolling. The Rigol DP832 is the powersupply Parker and Stephen currently use. Has the funky keypad. ESP8266 is a low cost wifi module that has been in the maker space for the last couple years. IoT BBQ? Stephen thinks its getting silly. Parker thinks IoT is just going to advertisement saturation. Stephen did a guest lecture for the Iron Yard. It is a coding school. He gave a hardware based lecture. Covered the toolsets needed to design hardware like EDA Tools. Stephen pimped the MacroWatch. Josh the sound guy trumps Parker and Stephen in figuring out where .ino file extension comes from. Parker wrote a blog post about programming for production. Heathkit launches a new website

Parker ordered all the parts for the SAIM this week. The v-slot rails and brackets from OpenBuild, iES-1706 servos from Leadshine, and 3D printed parts from Shapeways. MacroFab uses 3D printed parts to make custom spacers and tooling for assembly of PCB boards. Parker will be adding acceleration to the motor controller code to make sure the SAIM does not jerk around to much. Maximum Smoothness as Stephen puts it. Stephen has bee working more on the FX Dev Board. The board has a couple different power rails. It has +15VDC, -15VDC, an adjustable +9VDC and a half rail that tracks the +9VDC rail. The half rail uses a voltage divider for the reference voltage and is powered by an opamp. See Figure 2. The 16in/16out board that Stephen made has a 16bit A/D and a 16bit D/A on it. MAX5217BGUA+ and MAX11100EUB+. One uses I2C and the other uses 3 wire spi which Parker thinks is unfortunate. See Figure 2. Stephen has some old mylar 60's era caps that his mentor in junior high gave to him. They are 500pF caps. The Super

Audio quality of the podcast leveled up! Stephen and Parker went over to The Pharmacy Recording Studio which is run by Josh Moore. He hooked them up with 2 (!) microphones and a nice an acoustically pleasing room. Big thanks to Josh! Parker has been working on the X-Y Platform which has been code named the SAIM which stands for Semi-Automatic Inspection Machine. Half of Parker's job is coming up with "cool" acronyms. The SAIM will be a PCB inspection machine for low volume runs at MacroFab. See Figure 1. Parker gets Open Beam and Open Builds confused again. Similar names and similar products! Parker is using Open Builds V-Slot Linear Rails for the SAIM. Controlling the SAIM is the Macro PLC. It is a in house designed CNC controller based off the Parallax Propeller. Stephen has been working on the FX Development board. This board has all the power supplies and trimmings you need to develop guitar pedals, analog effects, and synthesizer circuits. The board has two solder-less breadboards as well built in. See

Stephen and Parker have been testing the main opamp for the OPA541. Stephen wrote a blog post detailing the opamp tests with simulation and real world testing. GitHub link to the repository for the SSPS. Giant 200W 8Ohm resistor. Liquid Cold Plate Heat Sinks for cooling the opamps in the SSPS. Isolators for the opamps made out of Aluminum Oxide. Part no. 4180. They make Beryllium Oxide Ceramic isolators but not in the right size. Antek transformers is the company that makes the Doughnut (Toroidal) Transformers Parker and Stephen are looking at. Really neat Super Capacitor Flashflight. A 30F 3V cap would weigh 5.685x10^-12 kg more fully charged vs discharged. It would take roughly 176 billion of these super caps to have a charge weight gain of 1 kg. Carbon film capacitors sounds almost as cool as carbon nano tubes. If they can replace bypass caps it would make compact board layouts easier. President Obama going to sign bill to combat chip piracy. FTDI rejoices? Microchip releases the MPLAB Xpress which is

Stephen continues his work on the Stupid Simple Power Supply (SSPS). He decided to go digital voltage control over analog. Also he has been trying out MultiSIM BLUE by Mouser for circuit simulation. See figure 1. Parker has been working on a X-Y gantry platform and an industrial level controller based on the Parallax Propeller P8X32A. See figure 2. OpenBuilds Linear Rail V-Slot. R/C StrandBeest. The original ones are giant monsters of kinetic art. Atmel releases the ATmega328PB. Has essentially double what the original 328P had. Only comes in SMT packages. Supports capacitive buttons built in which is cool! Parker decides that the lower the voltage a MCU can run at the better. Xilinx rumored to be bought by some unknown company. Stephen and Parker guess what company it is. To all chip and part manufactures out there, dimension to the center of pads please. Thanks. Special thanks to whixr over at Tymkrs for the intro theme!

Stephen talks about the Stupid Simple Power Supply (SSPS). He designed a OPA541 breakout board for testing. See figure 1. OPA541 Datasheet : Street price of $21.88. Parker brings up that blinky LEDs are the most important part of a project. He is designing the control panel and chassis for the SSPS. FTDI is again at war with counterfeit parts. Microchip buys out Atmel for $3.8 Billion. The consolidation of semiconductors continues. France building a huge solar roadway. This again? Special thanks to whixr over at Tymkrs for the intro theme!