Rick Kimball wrote:If they are truly analog you will need to use a voltage divider or it will fry the analog peripheral.
Yup will do, and yes it's truly analogue.... photo of bench test circuit below...
It's a bit of a rats next, but essentially there's:
* a TSSOP14 to DIP adaptor housing the MAX31856, connected via Software SPI to the Nano
* a small amount of input circuitry on a daughter stripboard for the K-type, basically capacitors for filtering.
* pull down resistors for some of the analogue inputs - I've just been adding some fault detection code which flashes a warning graphic if a sensor is disconnected
* Software SPI to a single OLED display - unfortunately I've had to drive the OLED's and MAX from different software SPI buses because the libraries stomp on one another.
* Voltage divider/pulldown for the Bosch NTC M12 ( 0 280 130 026) Analogue input - already being driven at 3.3 volts.
Not pictured is the boost sensor part, because it's in the vehicle on the existing production setup. This is the part being used -> https://www.aliexpress.com/item/New-Hig ... 21605.html
There are probably other better choices but this part is the most economical that covers the range of pressures that I need.
I've found some posts on the forum that seem to suggest issues with multiple devices on the same h/w SPI bus, is this still the case?