I must apologize for the late release of the weekly report this week. I was busy coordinating a Hackathon of a leading aerospace vendor to tackle a true business challenge. It was a very fun experience to work across many different groups and bring them together into one room to tackle this challenge.
At the end of the event, we not only achieved what we had set out to do, but we also were able to help many individuals that only worked a small portion of the overall problem understand the problem as a whole. It helped us develop a short term solution as well as lay the groundwork for a longer term digital tool that will provide many benefits to the user community. There are few things more fulfilling than helping solve challenges like this. Having coders, users, and coaches all in the same room working towards an end goal helped us come out ahead. Now for some much needed rest.
This Bluetooth module measures 3.25mm x 8.55mm x 0.9mm, and comes complete with an embedded antenna. This little device uses the Nordic Semi nRF52832 SoC device at its heart. This means that it provides Bluetooth 5 while also providing an ARM Cortex M4. On board it also has 512kB flash and 64kB RAM. This little device can practically fit anywhere. You can almost fit 5 of these modules on top of a standard MicroSD card. Based upon my research, I believe that this is the smallest overall footprint of Bluetooth 5 modules that include an antenna.
FastCap Systems has launched a board mountable ultracapacitor solution that is designed for low voltage electronics. It provides a nominal 470mF capacitance in an 8mm x 11mm x 2.3mm package. The device can use reflow for board assembly, making it compatible with traditional, high volume electronic manufacturing methods.
For those not familiar with the Barr group, they specialize in safety critical embedded firmware. As part of this expertise, they have released their Embedded C Coding Standard. Its stated goal is “to minimize bugs in firmware by focusing on practical rules that keep bugs out–while also improving the maintainability and portability of embedded software.” The PDF version of this coding standard can be downloaded from their website for free, or a printed copy can also be ordered from their website for a very reasonable cost.
Ok, so you are asking, what does this have to do with electronics? Actually, a lot if you are working within the right fields. Kalman filters are used for fusing together datasets of different types of sensors. This effort allows each sensor to help the other overcome weaknesses found in each individually. By combining each of these sensors together, their cumulative strengths are combined to create a solution that increases the accuracy and precision of the solution. The downfall is that there is some heavy math that is involved. To help understand what is going in in the background of a Kalman filter, Tim Babb, has presented what a Kalman filter does in a visual method that really helps understand what is really happening.
This is a hard one to title. You might be thinking, how does one emulate a physical device? In this case, Peter Misenko has provided a simple device that can be inserted into a CR2016 or CR2032 coin cell holder on a PCB (holder type dependent) to power the board. In the comments there are a few suggestions on how this could be improved to provide a more accurate coin cell simulant while powering the device.
If you are into 3D printing, or other applications that use small stepper motors, this write-up is for you. It goes through a simple, but detailed approach to determining how accurate these little micro-stepping drivers really are. It is found that the worst performer is the popular TI DRV8825. I love seeing data presented in the graphical details. Many times we are too focused looking at raw data that we forget that we are visual people.
As you can tell, this week I was doing research on driving stepper motors. In the previous link I shared the issue that the DRV8825 drivers have, but don’t be discouraged, there are a few things that can be done to fix the issue. Some of them have to do with the driver. The other part of the solution, is a hardware solution. This solution adds 4 diodes inline to the leads to the motor. This helps smooth out the drive.
If you are interested in seeing how your motor might match up with one of a few popular small stepper motor drivers, then this spreadsheet calculator created by Ryan Carlyle may be of use. It is a pretty intensive spreadsheet to allow you to put in the parameters of your motor, and then get an output of how well it should step, and other vital information. It is found in a Github repository. There are future efforts to add other stepper motor drivers. If you would like to help with the effort stop by his repository and see where you might be able to add some data.