Legal Removal Request

Post: Hi, We have connected the PI to an H bridge and are attempting to use this to measure soil resistance. We have two sets of probes, one set are fixed (remote) and the other set moves (mobile), to take measurements. We included a shunt resistor, whose resistance we separately determined, to enable us to calculate the current from the voltage, initially. We get ghost voltages from the mobile probes when the circuit is open, which we assume is down to the mobile probes acting as antennae, Previously the circuit allowed us to accurately calculate the resistances of some resistors that were placed in where the probes would go for testing purposes (327 ohms for a 330 ohm resistor and 151 for a 150 ohm resistor). Now the circuit is giving readings that are often exact multiples of the shunt resistor, although there is no consistency in these values (e.g. the same circuit when measuring once per second can give 2, 3 or even 20 times the shunt value).