3.1.5 DC Power Monitoring
The SAM9X75-Curiosity board embeds a DC Power Monitor device performing power calculations and energy accumulations on the three main SAM9X75D2G power rails. This function is ensured by the PAC1934 Current and Power Measurement IC.
Data can be retrieved through an I²C interface connected either on SAM9X75D2G or on a computer through a USB Micro-B connector. The protocol conversion from I²C to USB interfaces is ensured by a Microchip Serial Converter Chipset MCP2221A.
The following figure shows the DC power monitoring schematic.
The following table shows the DC power monitoring configuration signal selection.
| J38 | J39 | Interface | PIO | Signal Name | Signal Description |
|---|---|---|---|---|---|
| Jumper 3-2 | Jumper 3-2 | SAM9X75D2G | PC0 | PAC_I²C_DATA | TWI interface connected to SAM9X75D2G (PAC1934 driven onboard by the MPU) |
| PC1 | PAC_I²C_CLK | ||||
| Jumper 2-1 | Jumper 2-1 | USB Micro-B connector (37) | – | – | TWI interface connected to MCP2221A (PAC1934 driven externally through USB) |
| NC | NC | Disconnected | – | – | – |
| – | – | Other settings N/A | – | – | – |