![]() ![]() Using typically optocouplers to interface your ADC to your MCU. ![]() What you do instead is usually put the ADC on the unprotected side, and isolate the digital interface to the ADC! But I digress.īasically, isolating an analog signal and still reproducing it with a high number of bits is hard, and nearly impossible when you want accuracy at DC. I question your boss's logic when it comes to industrial standards: Where you need that level of isolation, I'd presume you want something very different than a raspberry pi running general purpose operating systems for safety reasons. However because this is for a prototype that should be up to Industrial safety standards, my boss wants me to isolate the 10V from the 3.3V logic. I would appreciate it if somebody more experienced would share his knowledge.Įdit: I have decided on using 2 ADS1115/ADS1015 instead of MCP3004/3008. I would use an opto-coupler if this was a digital signal, but I am not sure if there is a way to achieve the same level of isolation while reading analog values. So I was wondering if there is a method to read analog values, without a voltage divider that is safer to use when reading higher voltages with low logic voltage components. My Google search didn't yield any answers to me. I don't really know a method to do this though while reading analog signals. Simulate this circuit – Schematic created using CircuitLabīecause this is for a prototype that should be up to industrial safety standards, my boss wants me to isolate the 10 V from the 3.3 V logic. I am aware that I could use a voltage divider like this: For now, 10-bit resolution is good enough. I will be using the MCP3004/3008, as I got lost in the datasheets of the TI counterparts. In another example, sometimes excessive frequency can be handled with digital prescalers or IF downconversion.Įlse as far as I can see, if you need something in the range of a few microsecond response, then you would need the high speed ADC hardware.I want to implement an ADC as an extension to a Raspberry Pi, so that it has the capability to read analog signals. In fact, it makes an interesting question to ask, "have you thought about using a diode-RC peak detector, in front of the ADC?". Peak detection is effectively an active filter, in the analog domain the difference between charge/discharge is provided by a diode or synchronized transistor switch. But most applications of peak detection have a slow fall off to zero, in order to differentiate between this peak and the next one. ![]() As you know, a peak detection function must have some defined fall off rate, which can be zero if necessary. So for spot sampling, you would not filter at all. The built in problem is that by its nature, averaging or low pass filtering defeats peak measurements. That would give you a very slow but believable quantity. You are limited by orders of magnitude in the available sample rate, but since you are (or seem) focused on amplitude peaks, you could take spot samples for example. In particular, what information you need to extract from it. This depends on the nature of the signal. If so, is there any way that I could possibly modify the output (like perhaps adding any components) so that I could make sense of it on my due? ![]()
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