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For my embedded systems project, I decided that I wanted to create a weight scale. Naturally, I found the HX711 amplifier that would be perfect for this application. My question is, is it possible to use the HX711 as an instrumentation amplifier without using its built in ADC? The specifications of my project make it so that it's highly preferred if I could use the ADC built into the micro-controller that I'm using (KL43Z).
Thanks for any responses.
No, there is no facility (or pin) on that device that gives you the analogue output. Either use the digital output or choose another chip. An idea would be to use a differential bridge amplifier with in-built digitally controlled programmable gain such as the LTC6915: -
There are plenty of devices out there that would appear to fit the bill. The LTC6915 is just an example of one of them. Check offerings from Microchip, Texas Instruments, Analogue devices, Maxim etc..
From the image given, we can confirm that you cannot get amplification output separately from HX711 amplifier. Also, there is an advantage found in this amplifier which is it has 24 bit ADC unit that is superior to your MCU KL43Z's ADC resolution of 16 bit. Hence, just establishing a serial communication between HX711 and KL43Z is adequate.
If there is no way to communicate, then using instrumentation amplifiers like AD623 is a good choice which is not complex in design and can easily set the gain with a simple gain resistor as you want. For reference, click here.
Here is the sample of Data Acquisition using AD623.
