Monthly Archives: November 2019

Converting a Binary Table To Hex With Power Query

Posted on 26-November-2019 by mathscinotes

I was recently given a specification for a Digital-to-Analog Converter (DAC) that contains a table of register settings that correspond to the DAC's output voltage. Each row of the table corresponds to one register setting and each column corresponds to a register bit. Thus, each table cell corresponds to a single bit – a 1 or 0. A simplified version of this table is shown in Figure 1 – a simplified version of the much larger table I was working with. Continue reading →

Posted in Excel | 2 Comments

Steinhart-Hart Thermistor Calibration in Excel Using Matrix Formulas

Posted on 2-November-2019 by mathscinotes

I had a job this week that required that I use the Steinhart-Hart equation for modeling the thermistor resistance versus temperature relationship. The requirement was driven by the customer's need for high accuracy. Most thermistor applications do not demand high accuracy, but this application can tolerate no more than ±0.2 °C of error.  This means that I cannot use the β-based thermistor model, which in this application would have an error of more than ±2 °C. This page will show how how to perform an efficient 3-point calibration using Excel and a bit of matrix math. As a side benefit, I am using this workbook as an example of matrix math in my Excel tutoring at a local library. Continue reading →

Posted in Electronics | 2 Comments