89S52 Thermistor Thermometer: LCD version

thermo

by Wichit Sirichote:

This is the 2nd version of Thermistor Thermometer Project done by another group of my student. The 1st version having 4-digit 7-segment LED shows the use of simple display device. For applications that needs text display, this LCD version is more suitable and easy to adapt for many kinds of measuring devices.

89S52 Thermistor Thermometer: LCD version- [Link]

Power supply IC generates low-noise bipolar (+/-) power rails

3265

by Graham Prophet @ edn-europe.com:

LTC3265 is a high voltage, highly integrated, low noise dual output power supply IC which takes a single positive input supply (VIN_P) and generates low noise bipolar rails up to ±2•VIN_P without any inductors. High voltage boost and inverting charge pumps deliver low noise dual outputs with post-regulating ±50 mA LDOs

The device includes a boost doubling charge pump, an inverting charge pump and two low dropout (LDO) regulators. The boost charge pump has a 4.5V to 16V input range and powers the positive LDO post regulator from its output, VOUT+. The inverting charge pump has a wider input range (4.5V to 32V) which may be connected to either the boost input or output. The negative LDO post regulator is powered from the output of the inverting charge pump, VOUT-. The LTC3265 is suited for a variety of applications that require low noise bipolar supplies from a high voltage input, such as industrial/instrumentation low noise bias generators, portable medical equipment and automotive infotainment systems.

Power supply IC generates low-noise bipolar (+/-) power rails – [Link]

Delay using 8051 Timer

The major component of this circuit is Microchip’s SST89E54RDA-40-C-PIE, which is a pin-for-pin compatible with typical 8051 microcontroller devices. It has a built-in timer used to produce accurate time delay. The light emitting diode (LED) is connected through the 330Ω resistor to indicate the time delay. The blinking LED switches ON for 1ms and switches OFF for 1ms that indicates toggling from LOW to HIGH and HIGH to LOW. Output PIN P2.2 can be connected to an oscilloscope to generate a square wave.

SST89E58RDA-40-C-PIE comes with 72 Kbyte of on-chip flash EEPROM program memory that is partitioned into 2 independent program memory blocks. The primary Block 0 occupies 64 Kbyte of internal program memory space and the secondary Block 1 occupies 8 Kbyte of internal program memory space. The 8-Kbyte secondary blocks can be mapped to the lowest location of the 64 Kbyte address space; it can also be hidden from the program counter and used as an independent EEPROM-like data memory. In addition to the 72 Kbyte of EEPROM program memory on-chip and 1024 x8 bits of on-chip RAM, the devices can address up to 64 Kbyte of external program memory and up to 64 Kbyte of external RAM.

This design integrating Microchip’s SST89E54RDA-40-C-PIE would be used if high-accuracy, precision and timing resolution of timed events are required to activate or deactivate control outputs based on programmed time intervals. Time delay applications include pump control, food processing, and packaging control where precise ON/OFF control is necessary.

Delay using 8051 Timer – [Link]

IC monitors multicell battery packs

Intersil ISL94203

by Susan Nordyk @ edn.com:

The ISL94203 battery-pack monitor IC from Intersil monitors, protects, and cell-balances three- to eight-cell rechargeable battery packs, supporting Li-ion CoO2, Li-ion Mn2O4, and Li-ion FePO4 chemistries. Its internal state machine has five preprogrammed stages that accurately control each cell of a battery pack to extend operating life.

In addition to functioning as a stand-alone battery-management system for rechargeable Li-ion battery packs, the ISL94203 can be used with an external microcontroller communicating via an I2C interface. The device integrates high-side charge/discharge FET-drive circuitry, which allows the battery pack to be securely ground referenced.

IC monitors multicell battery packs – [Link]

Mesa-Video : 800×600 Digital video for Arduinos

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blackmesalabs.wordpress.com has build a video system for Arduino boards:

This post describes Mesa-Video, a low cost, low power, small size and fully Open Source Hardware and Software solution for providing 800×600 digital video for Arduino ( and other ) microcontrollers. Mesa-Video makes it quick and easy to display text and 24bit color graphics from any MCU using a single UART serial port pin. Applications for Mesa-Video are embedded projects requiring video output and embedded developers wanting real time visibility into their system operation. Mesa-Video is the 1st of multiple Mesa-Modules planned.

Mesa-Video : 800×600 Digital video for Arduinos – [Link]

Arduino Oscilloscope

arduino-oscillo

Noriaki Mitsunaga has build an Arduino Oscilloscope using minimum parts. He writes:

I have created a simple Arduino Oscilloscope as above picture shows. Here is its summary. You can build your own!

Arduino Oscilloscope – [Link]

MCP2221 HID Library

mcp2221breakout

Zak’s Electronics Blog published a new library and breakout board for MCP2221 USB to UART interface IC:

This is a library for interfacing with the HID features of the MCP2221 USB to UART and I2C/SMBus serial converter from Microchip. The converter includes 4 GPIO pins, 3x 10-bit ADCs, 1x 5-bit DAC and more. Microchip does provide a library for interfacing with the chip, however it is supplied as proprietary DLLs. This project aims to be an open-source and multi-platform alternative. libraryThis library also makes use of HIDAPI.

MCP2221 HID Library – [Link]

ESP8266 + Attiny85 + DHT22 Temperature/Humidity Logger

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by guibom @ github.com:

Basic ESP8266 + Attiny85 + DHT22 Temperature and Humidity logger. I’ve made this to experiment a bit with the ESP8266 wifi module, and hopefully make a remote sensor that posts the data to my server.

I wrote the code to work with both an atmega328 and a attiny85. The mcu sleeps in between readings, consuming about 35uA while powered down (the ESP module, even when chip-disabled, is responsable for about 80% of that).

The UDP messages are very specific to my use case; I have a node-red UDP listener that receives JSON strings from the logger and forward them as MQTT messages. But it should be very easy to change it to send whatever you might need.

ESP8266 + Attiny85 + DHT22 Temperature/Humidity Logger – [Link]

Enclosure 1455 NHD won’t be scared by a hot summer

obr1744_1

The latest extruded aluminium enclosure from Hammond production – 1455 NHD is suitable even for devices requiring more intensive cooling.

The latest addition to the family of the popular 1455 enclosure series is the enclosure with “NHD” suffix – where “HD” marks “Heat Dissipating” design. Six fins (zones) with cooling ribs significantly improve cooling. With its “N” size it´s suitable for PCB of the “Eurocard” size (100x160mm).

Possibilities of the new enclosure
They´re really wide. Thanks to seven inner slots, it´s easy to find a suitable position for your PCB. Removable front panels consequently secure a PCB against movement and at the same time they can be easily machined by drilling/ milling for usage of various connectors, switches, LEDs,…

And it´s still not all …
As the body of the enclosure consists of two pieces – with a removable base plate, it provides excellent reach to inner electronics even in case, when we don´t want to remove the PCB from the enclosure. The enclosure also contains six internal and two external T slots enabling installation of various components inside (by fixings sliding into the slot) or enables fixing of the enclosure to a panel/wall or similar.
Upon request we´re able to provide you any of the two versions – 1455NHD1601 (natural elox) as well as 1455NHD1601BK (black).

Enclosure 1455 NHD won’t be scared by a hot summer – [Link]

Triacs – How to calculate power and predict Tjmax

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An application note from NXP on how to calculate the power dissipated by the triac:

This Application Note describes how to calculate the power dissipation for triacs and Silicon Controlled Rectifiers. Thermal calculations are also included to help the circuit designer to predict the maximum junction temperature or calculate the required heatsink thermal resistance. Four worked examples ensure that all the power and thermal questions that arise during the design process are covered.

Triacs – How to calculate power and predict Tjmax – [Link]