It is very nice little and simple temperature measuring circuit with PIC16F688...PIC is driven with internal RC oscillator so it requires only pull-up resistor on MCLR pin. DS18B20 sensor requires 4K7 pull-up resistor on data line and display requires 1K resistor on its RX line. Some wires are also prepared for ICSP. Code is written in CCS C compiler.
Display is uLCD-128 from 4D Systems; 128x128 pixel resolution, 65K colors CSTN LCD display with white LED backlight. It has on board flash memory for storing images. Power supply for the display is 5V and serial interface is 0 to 3.3V, that's why a series resistor (1K) is required on display's RX line. Display is very easy to use and it has a built in graphics commands such as LINE, CIRCLE, TEXT etc.
The thermometer display on the left side of the display requires some corrections. That is in progress...
The thermometer display on the left side of the display requires some corrections. That is in progress...
I did a correction on the scale (Figure 3). The height of the red bar exactly corresponds to value now, but it's not possible to align text labels to divisions.
Sensor is Maxim's One Wire digital temperature sensor DS18B20 with 9 to 12 bit resolution and +-0.5 degree Celsius accuracy between -10 and +85 degrees. .
I added power supply from USB port...