diff --git a/fast-servo/pyfastservo/dac.py b/fast-servo/pyfastservo/dac.py
index a523ffc..4de7240 100644
--- a/fast-servo/pyfastservo/dac.py
+++ b/fast-servo/pyfastservo/dac.py
@@ -17,8 +17,7 @@
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
-import mmap
-import os
+import time
import spidev
from pyfastservo.common import (
@@ -29,108 +28,58 @@ from pyfastservo.common import (
CTRL_ADDR,
MAP_MASK,
PAGESIZE,
+ write_to_memory,
+ read_from_memory
)
# /dev/spidev2.0 <=> spidev.
MAIN_DAC_BUS = 2
MAIN_DAC_DEVICE = 0
-
DAC_VERSION = 0x0A
-def main_dac_init():
- spi = spidev.SpiDev()
+def spi_write(spi, address, value):
+ spi.xfer2([address, value])
- try:
- spi.open(MAIN_DAC_BUS, MAIN_DAC_DEVICE)
- spi.max_speed_hz = 5000
- spi.mode = 0b00 # CPOL = 0 CPHA = 0
- spi.cshigh = False
+def spi_read(spi, address):
+ rx_buffer = spi.xfer2([0x80 | address, 0x00])
+ return rx_buffer[1]
- spi_buffer = [0x00, 0x10] # software reset
- spi.xfer2(spi_buffer)
+def hard_reset(spi):
+ spi_write(spi, 0x00, 0x10) # Software reset
+ spi_write(spi, 0x00, 0x00) # Release software reset
+ spi_read(spi, 0x00) # Read reset address (necessary for reset to take effect)
- spi_buffer = [0x00, 0x00] # release software reset
- spi.xfer2(spi_buffer)
+def check_version(spi):
+ version = spi_read(spi, 0x1F)
+ print(f"DAC version: 0x{version:02X}")
+ return version == DAC_VERSION
- spi_buffer = [
- 0x80,
- 0x00,
- ] # for some reason it is needed to read the reset address for reset to actually reset
- rx_buffer = spi.xfer2(spi_buffer)
+def configure_dac(spi):
+ power_down_reg = spi_read(spi, 0x01)
+ spi_write(spi, 0x01, power_down_reg & ~(1 << 0)) # Clear EXTREF bit for internal reference
+ spi_write(spi, 0x0D, 0x00) # Set RREF to 10 kΩ for 1.0V reference
+ spi_write(spi, 0x04, 0xA0) # Enable on-chip IRSET (1.6 kΩ for 20mA output)
+ spi_write(spi, 0x07, 0xA0) # Enable on-chip QRSET (1.6 kΩ for 20mA output)
+ spi_write(spi, 0x05, 0x00) # Disable internal IRCML
+ spi_write(spi, 0x08, 0x00) # Disable internal QRCML
+ spi_write(spi, 0x02, 0xB4) # Enable 2's complement, LVDS interface, 4 LVDS lanes
- spi_buffer = [0x9F, 0x00] # hardware version
- rx_buffer = spi.xfer2(spi_buffer)
- if rx_buffer[1] != DAC_VERSION:
- print(f"Unrecognized device: 0x{rx_buffer[1]:02X}")
+def dac_self_calibration(spi):
+ spi_write(spi, 0x12, 0x00) # Reset calibration status
+ spi_write(spi, 0x0E, 0x08) # Enable calibration clock, default divide ratio
+ spi_write(spi, 0x0E, 0x38) # CALSELI = 1, CALSELQ = 1, CALCLK = 1
+ spi_write(spi, 0x12, 0x10) # Set CALEN bit
- print("=== Contents of spi buffer after DAC VERSION read back: ===")
- print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
- spi_buffer = [0x82, 00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
- # set to 2's complement and I to be first of pair on data input pads
- spi_buffer = [0x02, 0xB4]
- rx_buffer = spi.xfer2(spi_buffer)
- spi_buffer = [0x82, 00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
- for i in range(10):
- spi_buffer = [0x94, 0x00]
- rx_buffer = spi.xfer2(spi_buffer)
- print(f"0x{rx_buffer[0]:02X}{rx_buffer[1]:02X}")
-
- finally:
- spi.close()
-
-
-def read_from_memory(address, n_bytes):
- assert n_bytes <= 4
- addr = address
-
- try:
- f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
- with mmap.mmap(
- f,
- PAGESIZE,
- mmap.MAP_SHARED,
- mmap.PROT_READ | mmap.PROT_WRITE,
- offset=addr & ~MAP_MASK,
- ) as mem:
- start_addr = addr & MAP_MASK
- stop_addr = start_addr + 4
- # print(f"addr: 0x{addr:x}\tstart_addr: 0x{start_addr}\tstop_addr: 0x{stop_addr}")
- contents = mem[start_addr:stop_addr]
- read_value = list(contents)[:n_bytes]
- finally:
- os.close(f)
-
- return read_value
-
-
-def write_to_memory(address, value):
- value_bytes = value.to_bytes(4, "little")
- addr = address
-
- try:
- f = os.open("/dev/mem", os.O_SYNC | os.O_RDWR)
- with mmap.mmap(
- f,
- PAGESIZE,
- mmap.MAP_SHARED,
- mmap.PROT_READ | mmap.PROT_WRITE,
- offset=addr & ~MAP_MASK,
- ) as mem:
- start_addr = addr & MAP_MASK
- stop_addr = start_addr + 4
- mem[start_addr:stop_addr] = value_bytes
- contents = mem[start_addr:stop_addr]
- finally:
- os.close(f)
+ while True:
+ status = spi_read(spi, 0x0F)
+ if status & 0xC0 == 0xC0: # Both CALSTATI and CALSTATQ are 1
+ break
+ time.sleep(0.01)
+ spi_write(spi, 0x12, 0x00) # Clear calibration bits
+ spi_write(spi, 0x0E, 0x30) # Keep CALSELI and CALSELQ set, clear CALCLK
+ print("DAC self-calibration completed")
def manual_override(enable=True):
reg_contents = read_from_memory(CTRL_ADDR, 1)[0]
@@ -138,7 +87,6 @@ def manual_override(enable=True):
to_write = reg_contents | 0b1 if enable else reg_contents & 0b110
write_to_memory(CTRL_ADDR, to_write)
-
def power_down(channel, power_down=True):
assert channel in (0, 1)
@@ -152,31 +100,49 @@ def power_down(channel, power_down=True):
reg_contents = read_from_memory(CTRL_ADDR, 1)[0]
print(f"REG contents: 0b{reg_contents:03b}")
+def set_dac_output(value):
+ value = min(value, 0x3FFF)
+ low_word = value & 0xFF
+ high_word = (value >> 8) & 0x3F
-def write_sample(channel, sample):
- assert channel in (0, 1)
- if channel == 0:
- addresses = [CH0_HIGH_WORD_ADDR, CH0_LOW_WORD_ADDR]
- else:
- addresses = [CH1_HIGH_WORD_ADDR, CH1_LOW_WORD_ADDR]
+ write_to_memory(CH0_HIGH_WORD_ADDR, high_word)
+ write_to_memory(CH0_LOW_WORD_ADDR, low_word)
+ write_to_memory(CH1_HIGH_WORD_ADDR, high_word)
+ write_to_memory(CH1_LOW_WORD_ADDR, low_word)
+ print(f"DAC output set to: 0x{value:04X}")
- low_word_value = sample & 0xFF
- high_word_value = (sample >> 8) & 0x3F
- values = [high_word_value, low_word_value]
- for addr, value in zip(addresses, values):
- write_to_memory(addr, value)
+def configure_ad9117():
+ spi = spidev.SpiDev()
+ spi.open(MAIN_DAC_BUS, MAIN_DAC_DEVICE)
+ spi.max_speed_hz = 5000
+ spi.mode = 0b00 # CPOL = 0 CPHA = 0
+ spi.cshigh = False
+ try:
+ hard_reset(spi)
+ if not check_version(spi):
+ print("Unrecognized DAC version")
+ return False
-def write_ramp():
- signal = [i for i in range(16384)]
+ configure_dac(spi)
+ dac_self_calibration(spi)
- for value in signal:
- write_sample(0, value)
+ power_down(0, False)
+ power_down(1, False)
+ manual_override(True)
+
+ # Enable DAC outputs
+ spi_write(spi, 0x01, spi_read(spi, 0x01) & ~((1 << 4) | (1 << 3)))
+
+ print("AD9117 configuration completed successfully")
+ return True
+
+ except Exception as e:
+ print(f"Error configuring AD9117: {e}")
+ return False
+
+ finally:
+ spi.close()
-def main():
- main_dac_init()
- power_down(0, False)
- power_down(1, False)
-
if __name__ == "__main__":
- main()
\ No newline at end of file
+ configure_ad9117()
\ No newline at end of file