Sorry for the newbie question here, but what is the formula for calculating PSI from the output voltage? I am using the Seeed pressure sensor 114991178 - https://www.digikey.com/en/products/detail/seeed-technology-co-ltd/114991178/7387419. My reading is 3.11 when there is no pressure. I get 7.78 for max pressure but I’m not sure what the actual pressure is then - maybe 45-60 psi.
Thank you for your help!
what device are you using? XIAO? basicly you want to ust the analog to digital converter pins… it depends on what device how to set up
Hi there,
And Welcome here… So you need to provide more info. I see the specs on the Sensor(guage)
How is it connected and to What is it connected ? Linear or log?
The specs that matter are 
|Operating Pressure 174.05PSI ???
|Output|0.5 V ~ 4.5 V||
|Accuracy|±1.5%||
|Voltage - Supply|5V||
|Maximum Pressure|348.09PSI
Things like the MAP function in your code can be used to set the scale , Your analog ADC number of bits will give you a set resolution.
Provide more info , what you are doing and the code if you use the code tags above “</>” paste it in there.
HTH
GL 
PJ
Thank you for your help. I am using a LoraWAN Analog transponder and connecting the sensor to it. Here is the datasheet - PS-LB-NA LoRaWAN Analog Sensor User Manual - DRAGINO
I have been able to find 2 configurations that give me back data:
Configuration 1
Black = ground
Red = +5v_OUT
Yellow = VDC_IN: 0~30v sensor voltage input pin
Output in the .35 - .90
Configuration 2
Black = ground
Red = +5v_OUT
Yellow = IDC_IN: 4~20mA current input pin
Output in the 3.06 - 8.02 range
you want to use config 1 because VDC-IN means Voltage DC Input
Config 2 is IDC-In… means I (current) DC In
you are going to have to manually calebrate the values by plotting a series of points and making an interpolation of best fit curve
Hi there,
So the Water Presure sensor specs are Specifications
Wokring Voltage: DC 5±0.5V
Working Current: ≤10mA (DC 5V)
Working Voltage: DC 0.5~4.5V
Working Pressure Rate Range: 0~1.2Mpa
Max. Pressure: 2.4Mpa
Destructive pressure: 3.0Mpa
Working Temperature: -20～+ 105Ԩ
Storage Temperature: -20～+ 105Ԩ
Measurement Accuracy: ±1.5%FS
Response Time: ≤2.0ms
IP65
Cycle Life: 1,000,000 pcs
Given the output looks to be Linear…:
If you connect it to an ADC input with 14 bits resolution, 60 PSI would be equal to 6841 or 0x1AB9
here is the Analysis:
# Constants
min_output_voltage = 0.5 # V
max_output_voltage = 4.5 # V
max_pressure_mpa = 1.2 # MPa
pressure_psi = 60 # PSI
adc_resolution = 14 # bits
psi_to_mpa_conversion = 0.00689476 # 1 PSI = 0.00689476 MPa
# Convert the 60 PSI to MPa
pressure_mpa = pressure_psi * psi_to_mpa_conversion
# Calculate the corresponding voltage output from the sensor for 60 PSI
voltage_output = ((pressure_mpa / max_pressure_mpa) * (max_output_voltage - min_output_voltage)) + min_output_voltage
# Calculate the ADC value for this voltage
adc_value = (voltage_output / max_output_voltage) * (2**adc_resolution - 1)
adc_value
HTH
YMMV
GL PJ