Digital 2 wire 4-20mA conversion to voltage modulated signal

Dave_W — Mon, 10 Oct 2011 22:26:49 GMT

I need to use a digital single axis accelerometer with capacity to go up to a few hundred g's. The only decent ones I've been able to get hold of are the ADXL180's from ADI. However my project is using the MCF51JM128 so I need to find a way to interface with the device as it uses a 2 wire digital 4-20mA interface.

Now from what I've read I can use a precision resistor and sample the voltage across the resistor through the ADC but then I must do a bunch of programming to convert that into something useful. I don't mind doing the work but I want to know if there is a better solution then bit banging a comms interface. Are there any IC's out there that convert it to a standard interface like SCI/SPI/I2C?

Thanks in Advance

Dave Wright

Re: Digital 2 wire 4-20mA conversion to voltage modulated signal

FridgeFreezer — Tue, 11 Oct 2011 18:37:09 GMT

Surely with the correct resistor values you should be able to do it on a normal digital IO pin?

topic Re: Digital 2 wire 4-20mA conversion to voltage modulated signal in ColdFire/68K Microcontrollers and Processors

Digital 2 wire 4-20mA conversion to voltage modulated signal

Re: Digital 2 wire 4-20mA conversion to voltage modulated signal