Hi
As I am also working on beaglebone <https://beagleboard.org/black> to measure 4-20mA sensor output with Receiver module <https://store.ncd.io/product/4-channel-4-20-ma-current-loop-receiver-16-bit-ads1115-i2c-mini-module/> using less power can anyone help me out with code to interface the 4-20mA current loop Receiver with beaglebone please ?? On Thursday, August 18, 2016 at 10:36:14 PM UTC+5:30, drhun...@gmail.com wrote: > > There is a TI reference design for 4-20mA loop interfaces > http://www.ti.com/tool/tida-00550. It is designed as a cape. > Iain > > On Thursday, August 18, 2016 at 4:24:45 PM UTC+1, Graham wrote: >> >> If you would think to Google "4-20 mA receiver" you could learn a lot. >> >> Peripheral IC's from TI and Maxim that have most everything you need all >> ready designed in. >> >> Modules you could interface to the BBB, etc. >> >> Application notes on how to design receivers, and things to worry about, >> common system problems that people have had with this circuit for the last >> 50 years. >> >> Good luck. >> >> == >> >> >> >> >> >> On Thursday, August 18, 2016 at 10:03:12 AM UTC-5, Przemek Klosowski >> wrote: >>> >>> On 8/17/2016 5:26 PM, bali...@gmail.com wrote: >>> >>>> I am wondering if a beaglebone black can be used to measure industrial >>>> 4-20 ma loops? I see there is an ADC feature, but the voltage range is >>>> only to 1.8V. Is it possible to set it up to work with the standard 24VDC >>>> circuitry involved with most 4-20ma loops? >>>> >>>> A 90 ohm resistor carrying 20mA will develop a voltage of 1.8V. This is >>> cutting it a little close, so I recommend 68 ohm, which is a more >>> standard/easier to find value anyway. So, just terminate your 4-20mA line >>> with this resistor, and connect it to the Beaglebone analog input. Of >>> course if you're in an industrial environment you need to watch out for >>> transients, noise and interference, especially since the Beaglebone inputs >>> are famously fragile, so include some serious input protection (e.g. four >>> diodes connected as two anti-parallel 2-diode chains, with a filter cap >>> across it and maybe some series resistance). Then again, you could follow >>> evilwulfie's advice to use a dedicated buffer op-amp. >>> >>> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/977d479f-238e-4638-83d2-d01dcf677c5b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
