ADS1231: Scale application

Hi Lynn,

See my responses below.

Best regards,

Bob B

Lynn Chen said:

Part Number: ADS1231

Hi,

Please check customer question as below. Thanks.

Application: Scale

1. SG1~SG4 is 50Kg Load Cell，so it can measure total 200Kg，from my bench test, E+(DC-5V)、E-(GND-0V)、OUT+(AINP)、OUT-(AINN)，when I press SG1~SG4 Load Cell in the same time and use meter to check OUT+ and OUT- voltage，there's only 0.003V voltage change, is that correct? [Bob] The design of the bridge is lacking a lot of information.  It would appear that the bridge is made up of several strain gauges instead of 'load cells'. If the elements are true load cells then each load cell would have excitation and output connections.  Also, load cells have not only capacity but sensitivity in mV/V which determine the output voltage of the load cell be volt of excitation at maximum capacity.  If the elements are actually 50kg load cells, then for a platform type measurement that I typically see the elements are connected in parallel.  So to know if 3mV output is appropriate I would need to know more information on the load cells themselves, how they are actually connected, and the actual weight that is being applied.

2. how to set ADS1231 gain？[Bob] The ADS1231 has fixed gain of 128.

3. If use MCU GPIO(DOUT), GPIO(SCLK), there's a 24Bit data，if with correct Gain setting，can i get 1Kg~200Kg result？[Bob] This would depend on actual sensitivity of the load cell configuration, but 1kg to 200kg  can most likely be measured, but the desired resolution is not clear. If the desire is to measure 200kg and the resolution is 1g, then this measurement would require 200,000 noise-free counts, and that would be difficult to achieve.