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 character LCDs, so it would be nice…
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 interface with 5V MCUs such as Arduino directly.…
A while ago, I did a tear-down of a Keithley 196 bench multimeter. Towards the end of that post I showed a picture of my breadboard setup for backing up the firmware EPROM (27128) in case I needed to re-flash…
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 channel can also be programmatically set from 1…
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 to build one…
LTC4151 is a high voltage I2C current and voltage monitor. It is capable of monitoring input voltage ranging from 7V to 80V with the onboard 12-bit ADC. It can also measure the high side current and an additional external voltage…
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 range. I created a comprehensive Arduino…
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 supports serial communications (e.g. devices equipped…
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 load much higher than…
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. With a TL431…
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 drive other devices directly could be potentially dangerous. This…
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.
I did a teardown of a BK Precision 4011 5MHz function generator a few weeks ago. Like most of basic function generators in old days, BK 4011 does not offer frequency sweep as an option. What it does include is…
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 so far and the techniques used to chart the data.
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 approach I took back…