I am developing a product to which you can connect any 4-20mA transducer. It contains an ADC and a uP (which has two UARTs, one of which is unused), and the 4-20mA value is readable via an RS232 serial port. Simple so far.
Now I would like to add HART (Master) capability. I don't need to write any HART software yet but I need to have all the required hardware in place.
I have done some digging and found the A5191HRT and SYM20C15 chips. Is this all I need, with them connecting simply to my 2nd UART and into the 4-20mA loop, or is there some additional stuff which is needed?
Also, which of these (or any other) chip is the best one to use, in say 100+ quantities?
Any feedback much appreciated.