Spaces:
Sleeping
Sleeping
| from periphery import GPIO | |
| from spidev import SpiDev | |
| from time import sleep | |
| WAKEUP = 0x02 | |
| STANDBY = 0x04 | |
| RESET = 0x06 | |
| START = 0x08 | |
| STOP = 0x0A | |
| RDATAC = 0x10 | |
| SDATAC = 0x11 | |
| RDATA = 0x12 | |
| RREG = 0x20 | |
| WREG = 0x40 | |
| class Frontend: | |
| def __init__(self): | |
| self.nrst = GPIO("/dev/gpiochip2", 9, "out") | |
| self.pwdn = GPIO("/dev/gpiochip2", 12, "out") | |
| self.start = GPIO("/dev/gpiochip3", 29, "out") | |
| self.dev = SpiDev() | |
| self.dev.open(0, 0) | |
| self.dev.max_speed_hz = 8000000 | |
| self.dev.mode = 0b01 | |
| self.start.write(False) | |
| self.powerup() | |
| self.reset() | |
| self.stop_continuous() | |
| def powerup(self): | |
| self.pwdn.write(True) | |
| sleep(0.1) | |
| def powerdown(self): | |
| self.pwdn.write(False) | |
| def reset(self): | |
| self.nrst.write(False) | |
| sleep(0.01) | |
| self.nrst.write(True) | |
| sleep(0.1) | |
| def read_regs(self, start, len): | |
| values = self.dev.xfer([RREG | (start & 0x1F), (len - 1) & 0x1F] + [0x00] * len) | |
| return values[2:] | |
| def write_regs(self, start, values): | |
| self.dev.xfer([WREG | (start & 0x1F), (len(values) - 1) & 0x1F] + values) | |
| def read(self, len): | |
| values = self.dev.xfer([RDATA] + [0x00] * len) | |
| return values[1:] | |
| def start_continuous(self): | |
| self.dev.xfer([RDATAC]) | |
| def stop_continuous(self): | |
| self.dev.xfer([SDATAC]) | |
| def read_continuous(self, len): | |
| values = self.dev.xfer([0x00] * len) | |
| def close(self): | |
| self.dev.close() | |