I'm at my wits end with the existing ADC setup (MCP3561 + MCP1501) due to poor performance and documentation, so I'm looking to find a replacement part which is easy to get working.
The device is measuring a 1kg-5kg load cell in real time for a control / measurement application. The samples per second will need to be more than 10, with as many noise free bits as possible. I moved the setup to a separate board from the rest of the electronics, so I'm open to redesigning the ADC board entirely.
The relevant details:
- the ADC board is powered by 5v over a 6 conductor cable, and has logic level shifters / buffers to convert from 3.3v -> 5v on either side. The 5v goes through a 3.3v regulator with good noise rejection on the ADC board, which powers 3.3v port of the buffer, and is available for electronics.
- CK, SS, and MOSI are seen as inputs on the ADC board and cannot be changed / driven on the ADC board
- MISO is an output on the ADC board and cannot be changed or driven on the main board
- a full duplex SPI interface is currently used, and UART (only tx/rx) via RS232 is also available
- only one differential channel is needed, ideally with a PGA of 64 or more (or whatever gives best accuracy)
These are the conductors on the cable (shielded mini-din6):
(1) 5V
(2) GND
(3) CK
(4) SS
(5) MOSI
(6) MISO
All I really need is gram accuracy with a 1kg load cell. The easier the part is to interface with from a software perspective, the better. I don't want to spend another week writing and debugging drivers again, only to have the device display undefined behavior. The price is no longer much of a concern since it's a low volume production and I have wasted a lot of time already. If there are samples available that would also be good.
Thanks,
an exhausted intern