We found that most designs need the same interface for manufacturing test and debug so we built this little programming board. This combines power, serial communications, and JTAG programming into one universal cable. This board acts as the breakout for that cable and also enables current measurement.
Small wearable device incorporates bluetooth, power amplifier, button LED, sensors, etc.
This scope capture is from the Ethernet clock line of a project where we were brought in to get it to pass EMC. Yellow is the signal in the time domain, red is the signal in the frequency domain. On this signal we had to tweak series resistor values to minimize the EMI.
Sometimes, nothing beats a good old fashioned breadboard. We were working on a project that needed a loud alarm. The client had an opinion as to the type of sound that they wanted so we created a little test circuit to drive various speaker elements. This way the client could ensure that the final solution was loud enough for their product. We could have instead provided multiple population options for different speakers but by testing early we were able to identify the preferred component.
This is a photorealistic rendering of a small USB dongle PCBA. It needed to fit within a custom enclosure so we exported a 3D model (STEP file) of the board for the mechanical designer to incorporate into his design. This makes the mechanical integration much easier because we can quickly identify conflicts. You may notice there are many missing components - this is because we originally designed in additional features like USB Tx & Rx LEDs but later omitted them for final production. This also shows our preferred approach to labeling test points with their actual signal names, or a close approximation.
This is a block diagram for an entertainment lighting fixture. It included a little bit of everything: high power LED drivers, closed loop control systems, wireless connectivity, and a few cable harnesses to connect the three different PCBAs. Most of our projects are fast paced with very little time to spend on documentation. So for diagramming we tend to do a lot of hand drawings to convey the point across without getting ensnared in a graphics program. The goal is to communicate the information quickly and effectively.
Texas Instruments has a common development board standard called the BoosterPack which allows one board to work with many different microcontrollers. This is a simple BoosterPack for a Zigbee wireless module. We designed this in an extremely short timeframe (including a one-day PCB turn) so that the product was ready for a trade show. The product met the customers timeframe, worked right out of the gate, and made a positive impact at the trade show.
This table is from a cloud based MySQL database and shows the results of a manufacturing test for one product. This is hosted in Amazon Web Services so that the information is always available and we can monitor testing in real time. For most products like this we track when the test occurred, the results, and whether it passed. Test results are used for statistical process control (SPC) by the manufacturer and client to ensure that production does not have any issues. This product uses multiple test stations so we track where the test was run too.
A printed circuit board is made up of multiple layers of copper sheet, from 1 to many. Each layer is a different pattern of copper and may contain ground, power, or signals. The stackup shows how the different layers shall be combined, and is developed based on the product requirements and the PCB vendor’s capabilities. This stackup is from a fairly complex medical device.
Printed circuit boards should have test points to make it easy to test the hardware during development and diagnose issues during production. This rendering of a board shows how we like to implement test points. First, they’re labeled with their signal name. This makes troubleshooting substantially easier since you can find the signal right away. Second, these test points are spaced at 0.100” spacing so we can solder standard headers to them. These headers allow us to leave wires connected without having to manually solder tiny wires to the test points. Finally, the signals are grouped by their function: SPI, power, etc.