Section 4
User Installed Components
Installing the connection headers and operation selection headers
NOTE
Installing in this case means inserting the header or component in the designated location and soldering its’ leads. A Soldering Iron (25 to 45W) with a 1/16” (max) tip along with 60/40, or equivalent, solder should be sufficient for this task.
If needed, install headers HDR1 and HDR2 in their designated location. The same applies for JP1, JP2, JP3 (M-20 only) and RST headers.
Installing the low frequency, cylindrical-type Crystal
Both the M-28P/O and the M-20P/O are supplied with a 32.768Khz, cylindrical-type Crystal.
Through-hole pads are provided for installing this crystal. It is recommended that the crystal case be soldered to the PC-Board rectangular ground pad, to minimize spurious noise pick-up. The MSP430Fxxxxx family of devices have internal, selectable, 12pF capacitors, so in most cases it will not be necessary to add external loading-capacitors. This feature needs to be selected by writing to the appropriate SFR. Consult the Texas Instruments
MSP430 manual for additional information.
Installing the HC49/US or HC49/U high frequency Crystal
Both the M-28 and the M-20 have through-hole pads for installing a high-frequency crystal. Most of the high-frequency crystals will require external loading-capacitors for proper operation. Pads for soldering the (2) surface mount capacitors
C4 and C5 (case size 0603 or 0805) are located near the crystal case outline. Consult the Texas Instruments
MSP430 manual for proper selection of the crystal and recommended loading capacitors value. In most cases this value is around 12 to 22pF. The crystal case should be soldered to the PC-Board rectangular ground pad.
|
