PIC18

Compact Flash based serial (RS232) data logger powered by PIC18F458

Summary This is a complete project with following features: Serial Data (received by built-in RS232 port of the PIC18F) logging with receive date/time Compact Flash data storage Last record display […]

Interfacing DS1788X / DS1288X RTC with PIC18F uC

This is an example program to interface Maxim DS1788X series RTC to a PIC18F microcontroller. The DS17287, DS17487, and DS17887 integrate a quartz crystal and lithium energy source into a 24-pin encapsulated DIP package. The same code may be used to interface Older DS1288X series RTCs with little or no modifications.

Continue reading →

SHT75 Humidity and Temperature Sensor with PIC18F uC

SHT75 from Sensiron is a fully calibrated (calibration constants are programmed individually to each sensor) digital output sensor. It has a I2C like (not compatible with I2C) interface. The sensors are really accurate. I have noticed three sensors close to each other giving an output only deviating by 0.1C of each other.

The attached source code is derived from an application note provided by Sensiron for interfacing SHT7X sensors to 8051 microcontrollers. Please note this code has temperature/humidity conversion coefficients for older (prior to V4) SHT75 sensors. If you use a newer V4 sensor update the conversion coefficients. The code was written for a PIC18F4580 IC and was compiled with HI-TECH PIC18 compiler.

Continue reading →

Interfacing TMP101 Temperature Sensor with PIC18

According to Texas Instrument, TMP101 is a two-wire, serial output temperature sensor available in SOT23-6 package. Requiring no external components, the  TMP101 is capable of reading temperatures with a resolution of 0.0625°C.
This is from a project I did in 2008. The given routines measure temperature from TMP101 and output it to the serial port of the microcontroller at one second interval. TMP101 was connected to the standard I2C pins of the PIC18F452 microcontroller used.

Continue reading →