Temperature and Humidity Logging Over Ethernet — I
I did a project on temperature/humidity logging a couple of years ago. In that project I logged the temperature and humidity readings in my basement lab over the course of a year. One issue with the...
View ArticleTemperature and Humidity Logging Over Ethernet — II
Last week, I discussed the construction of a network-capable temperature and humidity sensor using SHT21 and ENC28J60 with an ATmega328P microcontroller. In this post, I will show the results obtained...
View ArticleA DIY Vacuum Fluorescent Display Driver
In my previous post, I showed a simple vacuum fluorescent display filament driver built using a 555 timer and a custom hand-wound, center-tapped toroidal pulse transformer. And as promised in my...
View ArticleVFD Clock – Putting Everything Together
After I completed the filament driver and the circuit to drive the multiplexed VFD segments, it is time to finish the VFD clock project I had in mind earlier. On the circuit side, there isn’t too much...
View ArticleAn Isolated DAC Using PWM Output
Arduino‘s (ATmega328P) PWM outputs via analogWrite can be conveniently turned into analog voltage levels through the use of simple RC filters. Since the PWM outputs are not isolated, using them to...
View ArticleInterfacing TLV5620 With Arduino
TI’s TLV5620 is a budget 4-channel 8-bit DAC. While it is designed primarily for running with a power supply between 3V and 3.6V, it can be powered by 5V as well given its wide supply voltage range....
View ArticleBuilding a Constant Current/Constant Power Electronic Load
A while back I built a simple constant current electronic load using an aluminum HDD cooler case as the heatsink. While it was sufficient for a few amps’ load under low voltages, it could not handle...
View ArticleA Simple Serial Protocol
We can send and receive commands wirelessly with Arduino by using these cheap RF data link transmitters/receivers. I like these RF modules because they can be hooked up to pretty much any device that...
View ArticleLM92 Library for Arduino
LM92 is a 12-bit + sign temperature sensor from Texas Instruments. This sensor operates on the I2C interface and can achieve an accuracy as high as ± 0.33 °C within the typical temperature measurement...
View ArticleExtending DAC Resolution Using Digital Potentiometer
One way to extend the resolution of a digital-to-analog converter (DAC) is by employing a sigma-delta converter in software. The main disadvantage of such approach is the slow speed. Alternatively, we...
View ArticleModify An Off-the-Shelf CP2102 Module As An Arduino Programmer
A while back, I wrote an article on how to use a CP2102 USB/UART converter chip in place of an FT232RL to program an ATmega328P using Arduino bootloader. Of course, not everyone has the time or wants...
View ArticleMCP3903 Library
MCP3903 is a six channel Delta-Sigma A/D converter. It features six synchronous sampling differential channels which can be programmed to sample between 16 bit and 24 bit accuracy, the gain for each...
View ArticleDS3232 Clock Frequency Calibration
DS3232 is an extremely accurate RTC with a guaranteed accuracy of 2.5 ppm (0 °C to 40 °C), which translates into an error of just 80 seconds over the course of a year under the worst case scenario. I...
View ArticleOn Arduino Due PWM Frequency
I just got myself a couple of Arduino Due boards. While they were released almost two years ago, I have not really got a chance to look at these until quite recently. Arduino Due is based on Atmel’s...
View ArticleUsing Arduino Due’s True Random Number Generator
Arduino Due uses an Atmel SAM3X8E ARM Cortex-M3 CPU, which has a native hardware based True Random Number Generator (TRNG). In this post, we will take a brief look at how to use it in the Arduino...
View ArticleTurn Your Android Phone into a Wireless Touchpad
In this blog post, I will show you a simple way of turning your Android phone into a wireless touchpad. For this to work all you need is your Android phone, an Arduino board and a HC-06 (or HC-05)...
View ArticleYet Another Scanning Monochromator Build
A while ago, I saw a video on the signal path in which Shahriar modified his Verity EP200Mmd monochromator/detector and turned it into a scanning monochromator. Inspired by his work, I decided to do...
View ArticleInterfacing HDC1050 with Arduino
Recently, I got my hands on TI‘s HDC1050 low power, high accuracy digital humidity/temperature sensor chip. The supply voltage of this chip can range between 2.7V and 5V, making it possible to...
View ArticleReverse Engineering a Uniden Cordlessphone LCD
I recently upgraded my home phone system and thus was left with a couple of old Uniden DCT648-2 handsets. Most of the components inside are probably not salvageable but these handsets use 3×16...
View ArticleA Quick Look at the M5Stack ESP32 Development Kit
I recently received an M5Stack ESP32 development kit from Banggood. Although I have not used any ESP32 based development boards before, I have heard many good things about the ESP32 platform,...
View Article