| MCU | ATxmega256A3BU |
|---|---|
| Operating Voltage | 3.3V |
| Operating Frequency | 48 MHz/4 = 12 MHz |
| CPU clock configuration | 32 MHz internal oscillator calibrated to DFLL 48 MHz, prescaled to 12 MHz |
| Sleep mode | Power down |
| Peripherals enabled | ADC, RTC32, Timer0, UART, USB, Event System, DMA |
| ADC configuration | Operates with 12 MHz system clock, signed mode, 12-bit resolution, 1 MHz sampling rate, VCC/1.6 reference voltage, timer triggers over event system |
| ADC channels | Channel 0: Temperature sensor, Channel 1: Light sensor |
| RTC32 configuration | An external 32 kHz crystal is the clock source. RTC ticks for every one minute, interrupt on overflow |
| Timer0 configuration | The clock source is a 12 MHz system clock, timer overflow interrupt occurs for every 1 ms |
| UART configuration | Asynchronous mode, 9600 baud rate, 8 data bits, 1 stop bit |
| USB configuration | 48 MHz DFLL is clock source. USB 2.0 full speed mode, CDC Class |
| Event System configuration | Clock source is 12 MHz system clock, Ch-0 of the event system is used for timer0 interrupt |
| DMA configuration | Two DMA channels to transfer data from the two ADC channels to data buffer |
Table 1 shows the operating conditions of the ATxmega256A3BU MCU and the list of peripherals configured for sensor node operation.
Table 2 shows the power consumption values of the ATxmega256A3BU MCU with different sleep period values.
| S. No. | Active Period [sec] | Active Current [mA] | Sleep Period [sec] | Sleep Current [µA] | Average Current [µA] |
|---|---|---|---|---|---|
| 1 | 4 | 9.58 | 60 | 1.1 | 599.7 |
| 2 | 4 | 9.58 | 300 | 1.1 | 127.1 |
| 3 | 4 | 9.58 | 600 | 1.1 | 64.5 |
| 4 | 4 | 9.58 | 900 | 1.1 | 43.5 |
| 5 | 4 | 9.58 | 1800 | 1.1 | 22.3 |
| 6 | 4 | 9.58 | 3600 | 1.1 | 11.7 |
The power consumption of the RN2483 LoRa technology mote in active mode is 3.76 mA and in sleep mode it is 0.87 mA.