38
edits
Changes
add sections for CC1050<->ST7 and GPS<->ST7 busses
SP1 connects to four channels of U14, an 8-channel analog MUX. Pin 2 also connects to R111, non-populated, which would provide a pull-up to +5 at Pin 1.
==Internal Busses==
=== TI CC1050 to ST7 Bus ===
{| class="wikitable"
!CC1050
Pin
!CC1050
Name
!ST7
Pin
!Notes/Observations
|-
|19
|DI
|Pin18 / OCMP1_A / AIN10 / PF10
|U17 appears to be a level translator between CC1050.19 and ST7.18
|-
|20
|DCLK
|Pin30 / PC7 / SS / AIN15
|U7 appears to be a level translator between CC1050.20 and ST7.30
|-
|21
|PCLK
|Pin29 / PC6 / SCK / ICCCLK
|
|-
|22
|PDATA
|Pin28 / PC5 / MOSI / AIN14
|Voltage varies between 5 and 3.something volts depending on which side is transmitting.
|-
|23
|PALE
|Pin27 / PC4 / MISO / ICCDATA
|
|}<br />
=== GPS Chip to ST7 Bus ===
{| class="wikitable"
!GPS
Pin
!GPS
Name
!ST7
Pin
!Notes/Observations
|-
|
|
|
|
|-
|
|
|
|
|-
|
|
|
|
|-
|
|
|
|
|-
|
|
|
|
|}
==Components==
The following is a catalog of active components. Designators italicized still need positive identification; bold have been positively identified. Markings listed where known to help in identification. List additional markings when they differ.
When testing, it's important not to transmit on unlicensed frequencies. Emissions can be eliminated by replacing the RF amplifier with a jumper between pins 1 and 3, and terminating the load at the antenna connection. The amplifier is an SOT-89 device just above the "-" terminal of B3. To access the RF chain, the shield housing may need to be temporarily removed. Also remove the bias feed resistor just below the "L104" marking. Then, remove the transmitter antenna from the "ANT1" connections. Use a 50 ohm resistor across the two terminals to provide a terminating load and eliminate any further transmission. Near-field reception is still possible after making these changes.
== Reference ==
Here are some reference materials. This is an initial population of material, and this section will need significant cleanup - putting links up for now.