An embedded multi-purpose Ethernet controller: Application a temperature / light sensing slave board
Description
In the goal of monitoring remotely temperature and light level, we made a board able to read 4 temperature sensors and 2 photodiodes. The slave microcontroller is a 8 bit 20 Mhz PIC16C74 from Microchip (let's use the acronym PIC for the rest of the document). Upon order form our Ethernet Board (EED), the PIC select which sensor to active thru a 8 position analog multiplexer (DG528 from Maxim) and convert the analog signal into a digital 14 bit wide signal thru the AD679 from Analog Devices. The data form the given sensor is sent back to the FIFO included in our EED. The SX52 sends back the result thru ethernet frame to the PC.
Overview : our EED board has now another piggy back board to measure temperature
and light illumination.
This small telemetry application is very usefull in the sense that any temperature and light level can be monitored remotely. A PCB has been made for that purpose, and this PCB is mounted in piggy back to the EED board, as one can see in the next image :
