rs 232 dual commnunication

[Jorim]

Hello,

I have the following problem.

I've build an analog voltage regulator ( http://www.circuitsonline.net/schakelingen/71/voedingen/labvoeding.html) and I want to replace the potentiometers for digital ones. If that is done I want to let it communicate via rs232 so that I can regulate the voltage and amps. Beside that I want to see on my comuterscreen what the voltages an amps are.

How can I do that? How does the software work? And what do i need for hardware (selfmade, not an fpga module or something like that).

Regards,

Jorim

[Henrik_Volkers]

If you want to measure the voltage and current you need ADC 😉

The cheap and easy way is an µC of your choice with adc and uart , add a ttl3rs232 chip (like max232).

Without µC programming: use the RS232 flow control lines to bitbang something like a I2C communication. Maybe there are dig pot and adc chips that can chained up otherwise you need 4 chip select lines and you only have 3 easy to access output lines where one is needed for clk , one is data and one for CS???? so you need another I2C port extention chip for the CSs .... and you need to write a bitbanging protocoll for the RS232 in LabVIEW using the VISA serial properties....

Or you decide to use the good old legacy printer port .....

[Jorim]

I've just reseved(???) an PIC18F2520. This pis has 2 adc's on board. Is it posible to use this one combined with an max 232? Does someone has an .hex file that I can use for an PIC ic (18f252 or an other one) If this is posible?

[Coq_Rouge]

Using a PIC18F2520 is a good idea. In order to get something useful out of it. You need some equipment like a programmer. You must also do the programming job your self, as almost every MCU project is unique.

By the way. For this project you will only need 1 RS232 line. Your job will be to create a protocol so you can sort out the information sent from the PIC18F2520.