User`s manual
14 www.rabbit.com Getting Started
Figure 2.6 Test Points for Checking Voltage Levels on the PowerCore 3800
If you see the message “Could not open serial port”
• Another program (for example, a terminal emulator) is already using the COM port you chose for
Dynamic C or the programming cable is not attached to the correct COM port on the PC. To change the
COM port Dynamic C will use, choose Options > Project Options and click the Communications tab.
Select another COM port from the Serial Port pull-down menu.
If you see the message “Timeout while waiting for response from target”
• Check the programming and power cable connections.
• You might have a baud rate mismatch problem. Choose Options > Project Options and click the Com-
munications tab. Select a different value in the Debug Baud Rate dropdown menu.
• If you have a very slow PC or are doing other CPU-intensive tasks at the same time Dynamic C is try-
ing to download, you might get other timeout error messages. Dynamic C needs a lot of CPU time dur-
ing a download. Try stopping the other tasks to see if it helps.
Table 2-6. Description for Test Points in Figure 2.6
Test Points Expected Measurement
A, B, C: These pins are the center-
tapped power supply input. “B” is
ground. Both “A” and “C” measure
the voltage coming from the external
power supply
From B to A, 12 V AC or higher
From B to C, 12 V AC or higher
D: This capacitor terminal is an easy
place to access the board-level
ground.
E, F: These pins are the output and
input, respectively, of the 3.45 V
regulator.
From D to E, approx. 3.45 V DC
From D to F, approx. 5 V DC
R1
DS1
JP1
DS2
T1
U1
J3
Y2
U11
Y1
J1
R4
R2
R3
RT1
C6
R42
L1
U13
VBAT
J2
R54
JP2
R55
C35
C36
R61
R62
R63
R64
C33
U15
C37
C38
SG2
SG1
SG3
TVS1
C34
TVS2
R59
R60
D8
D6
R57
R58
D7
C32
D5
R56
D4
C31
U12
U10
C25
R37
R38
C27
C28
U7
U3
C17
U2
D1
C1
C3
R5
TP11
TP10
TP9
U6
C26
R40
C29
U9
R46
R48
R47
R43
R44
R34
C23
R33
C22
D2
R45
D3
R41
C30
R31
C19
R36
R35
C24
U8
R39
U5
U4
R29
C16
C4
R11
C8
C5
Q1
R24
R23
R16
C13
R7
C20
R32
R27
R28
C2
C9
R9
R8
R6
R12
R25
C14
R10
R18
R19
C10
C11
R30
C21
R17
R20
R21
R22
R26
C15
C12
Q2
R15
R14
R50
R49
U14
R51
R53
R52
CAUTION: HOT!
C67
R67
R118
R117
C7
R116
R13
C18
L7
TP14
TP16
TP12
TP13
TP15
D
A
B
C
EF