µCT
X-Ray Source
PSX10-WB-130 Microfocus Source
PXS5-724EA Microfocus Source
Connector
Chassis Ground
4.0V DC kV Control Source
HV Programming (4.0V = 80kV)
HV Programming Ground
Current Programming (2.5V = 100µA)
Standby Power (+12V DC)
HV Monitor Voltage (4.0V = 80kV)
Current Monitor (2.5V = 100µA)
Monitor Ground
+2.5V DC mA Control Source
+12 DC Operate Power
DC Operate Ground
Mating Connector :
Thoshiba DGO 73
X-Ray Detector
FDXD-1417
Dexis Platinum / GXS-700
DigiPan
Connector
(BL) Ground
(RD) +5V
(OR) +15V
(GR) -15V
(BL) RS422 A
(WH) RS422 B
Power Supply
Protocol
8MHz UART, 1 Start bit, No Stop bit
ADC Data is 12bit + 1 control (seems to be always 1)
Data is streamed out pixel by pixel, line by line, 1244x 13 bit data packets per CCD line
Flatpanel Detector
Fluorescent Screen
Mechanics
Stepper Motors
GRBL
Settings
M1: /dev/USB1
$0=10
$1=25
$2=0
$3=2
$4=0
$5=0
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=1
$21=0
$22=1
$23=7
$24=500.000
$25=500.000
$26=250
$27=1.000
$30=1000
$31=0
$32=0
$100=25.000
$101=200.000
$102=200.000
$103=250.000
$110=1000.000
$111=500.000
$112=500.000
$113=500.000
$120=20.000
$121=30.000
$122=10.000
$123=10.000
$130=125.000
$131=155.000
$132=150.000
$133=200.000
M2: /dev/USB2
$0=10
$1=100
$2=0
$3=0
$4=0
$5=0
$6=0
$10=1
$11=0.020
$12=0.002
$13=0
$20=1
$21=0
$22=1
$23=1
$24=250.000
$25=1000.000
$26=250
$27=1.000
$30=12000
$31=0
$32=0
$100=10.000
$101=10.000
$102=250.000
$103=250.000
$110=1000.000
$111=1000.000
$112=500.000
$113=500.000
$120=100.000
$121=100.000
$122=10.000
$123=10.000
$130=165.000
$131=175.000
$132=200.000
$133=200.000
Limit Switches
GND - Schwarz
VCC - Braun
SIG - Blau
A4988
Step Mode
| MS1 | MS2 | MS3 | Mode |
| GND | GND | GND | 1/1 |
| VIO | GND | GND | 1/2 |
| GND | VIO | GND | 1/4 |
| VIO | VIO | GND | 1/8 |
| VIO | VIO | VIO | 1/16 |
Current Limit
Current Limit = Vref x 2.5V/A
TMC2208
Step Mode
| MS1 | MS2 | Mode |
| GND | VIO | 1/2 |
| VIO | GND | 1/4 |
| GND | VIO | 1/8 |
| VIO | GND | 1/16 |
Current Limiting
The best way to set the motor current is by measuring the voltage on the Vref pin (0…2.5V) and adjusting the voltage with the potentiometer. The maximum settable motor current is 1.77A RMS (0.11Ohm sense resistors), but the SilentStepSticks can only be used up to 1.2A RMS.
Irms = (Vref * 1.77A) / 2.5V = Vref * 0.71
Vref = (Irms * 2.5V) / 1.77A = Irms * 1.41 = Imax
Vref → Voltage on Vref pin (Measure on Wiper of Potentiometer)
Irms → RMS (Root Mean Square) current per phase (Irms = Imax / 1.41)
Imax → Maximum current per phase (Imax = Irms * 1.41)
Rotary Stage
0.1° minimum resolution
AMS AS5147 Magnetic Encoder (On Axis)
Datasheet-
29.5mm Center Distance
~50mm gear diameter
Source & Detector
Distances must be known
Source - Center of Rotation (SOD - Source Object Distance)
Center of Rotation - Detector (ODD - Object Detector Distance)
Source - Detector (SDD - Source Detector Distance)
Reconstruction
Correction
Convert x-ray images to projections:
p(s) = -ln(I(s) / I(0))
p(s) : Projected Intensity
I(s) : Intensity recorded at detector after passing through an object
I(0) : Intensity at source (white reference)
Filtered Backprojection