The unit is comprised of 3 boards
The Mainboard, witch contains the DSP and a 1 bit PWM DAC for audio as well as headers for a HD44780 LCD, User Interface Switches, and the two daughter boards, one for the Analog Fronted (RX) and one for the Mosfets controlling the TX function.
The Analog Fronted board contains the 1MSPS Low noise ADC and is connected to the CPU with a high speed SPI link, This board contains 2 high speed op amps providing a gain between the two of them of 50, it also has isolation circuitry to isolate the fronted during the peak of the fly-back and keep the op amps from saturating.
The TX Mosfet driver board contains an Isolated 2ch Mosfet driver as well as the two mosfets to drive a double O coil.
I chose the Daughter board configuration to allow for easier upgrades in the future and make debugging easier.
The secret to it's deep penetration is low noise, Everything is designed from the ground up to minimize all types of noise. To do this XPI utilizes the following techniques.
1. Averaging: XPI takes 6 samples (first 5 detection and the sixth is a ground balance sample) during the fly-back decay and averages them each against the last 64 values for each sample. To do this we have to process 64 * 6 samples in real time! This level of performance is only made possible by the high powered XS1-L1 DSP. By averaging in real-time over each individual sample set an extremely high degree of noise removal is possible.
2. Insanely Powerful EM Field: Because of this, XPI will probably never pass electronic remittance requirements which govern this type of equipment and will therefore remain as an experimental kit only, but since I'm in this for more than money the advantages of a much stronger field are huge. A stronger field punches deeper into all types of soil while overpowering background noise that may be present in the area.
Combining these technology allow normally weak targets to sound out strong! Enabling the best detecting of small, deep targets as well as everything in between!