Puertos Bidireccionales en FPGAs

Los puertos bidireccionales en los FPGAs pueden ser un tanto confusos. No estamos hablando de definirlos como inout, sino de definirlos de tal forma que puedan enviar y recibir información.
Un puerto inout es normalmete utilizado para monitorear el valor de salida de un puerto, es decir, leer lo que estan enviando ó enviar a alguna otra salida lo que estan recibiendo, sin embargo, si desean leer y escribir información, esta única definición no será suficiente.
La imagen muestra un código utilizando la definición inout. Como mostraré en las imágenes del día de mañana, esto no funciona como se desea. El puerto LED es definido como inout, SWITCH, SWITCH2 y ENTRADA como in y SALIDA como out.

PCBs

The PCBs are almost done!! Today the solder mask arrives, so when finished I'll post a new picture.

GLCD Screen

After a lot of work, we are finishing the sterilizer's control. The image shows the GLCD screen with the temperature sensor connected. The FPGA is already managing all the valves and their periods along with the temperature's control. There's still work on the GLCD and on almost all the PCBs. Hopefully we'll finish this week!!!!

That's it. I took real values measuring the resistance and the voltage. The images show the real values and the theoretical values(left bottom corner on the first image) predicted by the mathematical model. Of course, I have to rise the temperature and read several values.
The current is on the order of hundreds of uA which is good because it prevents the self-heating.

Sterilizer's bridge

Researching, I found that the Wheatstone bridge it's the most common mode for obtaining a change of voltage due to a change of resistance. After a few elementary maths I've reached the resistance vs voltage equation. If I didn't make any mistakes, then the picture shows this plot. If I did have mistakes, then I will apologise (again) and re-do the job. Of course, being the plot positive or negative is just a matter of how the voltage is being measured.

Sterilizer's Temperature(Update)

Today, the RTD temperature sensors arrived. I can now put the correct plot. I don't think putting the Resistance vs Temperature equation to the FPGA will be a problem, but I'm not quite sure if it's worth the effort. Perhaps would be easier to obtain a linear regression and use the form Y=a+bX.

The known universe by AMNH

Un gran video. Una mirada al universo (en forma digital). Chequenlo, no se van a arrepentir.

The Known Universe