Electronics

Testing ER-TFTM028-4 Capacitve Touch Display

Nov 21, 2020 display reverse-engineering

Good debugging equipment priceless. Being able to gain insight into a system in a quick and clear manner greatly helps identify when issues occur. In first versions I like to add visual feedback for myself. This can be as simple as an RGB LED to detect status or as full featured as a touch screen display. For my senior …

Debugging Occasional Incorrect SCD30 Results

Oct 23, 2020 scd30 saleae

Currently, I am working with a Sensirion SCD30 CO2 and RH/T Sensor Module for both work and Senior Design. The module includes an IR led detection chamber for measuring CO2 as well as a SHT** relative humidity and temperature sensor for calibration of the CO2. This improves integration and is a pretty good deal if one …

KiCad Move Block to Sheet and Retain Annotations

Oct 20, 2020 KiCad Tips

The Problem Currently, I am working with one of my senior design capstone team members to develop and create the schematic. To get going faster and be sure to give everyone the opportunity to work on the design, we took alternating turns on design and layout. This created a problem for when we wanted to refactor the …

Un-killable microSD Card

May 27, 2020 FatFs microSD

In a previous post, I was talking about getting FatFs1 up and running on a custom board. However, I was having issues related to the power supply. My first hint was investigating if there were power fluctuations and if the SD was being provided the proper amount of power through the switch. This was my initial thought …

SD Cards and FatFS

May 26, 2020 FatFs microSD SAML11

Okay, I am not happy to admit I have spent far too long trying to get a SD card to work on my own PCB and microcontroller. I have always worked with Wiring based libraries in the past. This is essentially the Arduino ecosystem of libraries, so I have never had to dig down into the implementation. If you find yourself …

PMSA003I and Embedded Serialization

May 23, 2020 Ghidra PMSA003I

The PMSA003 is a small (sub $20) particulate matter sensor. As with most PM sensors, this module uses a fan and a laser to detect the size and counts of particulates in the air. As I am using the I2C version for current project, I needed to write the driver for it. When creating the struct, I realized the sensor's data …

Same or Reversed Wiring Harnesses?

Jan 19, 2020 harnesss JST socket-socket

There are two common ways to assemble wiring harnesses, of which appear to go by several sets of names. Most notable pairs are: "same" vs "reversed", otherwise known as "socket to socket" vs "socket to socket reversed", as well as, 1:1 vs 1:N styles. Regardless of the naming …

Starting the Tuning Fork Gyroscope, Background

Jan 17, 2020 gryoscope mems piezo tuningfork

For my sensors class, we have been tasked with designing some form of a sensor from the ground up. My group, consisting of a grad student, a fellow undergrad and myself, chose to implement a gyroscope. Gyroscopes are instruments used for measuring angular rotation. They are commonly packaged with accelerometers and …

K1-1508SA-01 Meets KiCad

Nov 24, 2019 K1-1508SA-01 kicad-tricks thumbswitch

The K1-1508SA-01 is a multi-directional switch perfect for adding cheap navigation functionality to designs. I was unable to find any 3D models or detailed footprints, so I created my own. As usual, it all starts with the datasheet... From here, I created the PCB land pattern in KiCad as described above. At this point, …

SMT Navigation Thumb-switches

Nov 10, 2019 navigation switches thumbswitch

Recently, I discovered navigation thumswitches or multi-directional thumbswitches. Fundamentally, they allow the user to switch between UP, DOWN, and SELECT. Up and Down are selected by angling the shaft, while Select is by pushing the shaft in. These are very simple switches and in my opinion, are an elegant solution …