Illustrate hardware integration issues faced during todays construction.
9 JULY 2010
- Need to remove 90deg SMA connectors from radio board and solder SMA pigtails to solve SMA interference problem between Radio and Antenna BD
- Top and Bottom solar panel mounting surfaces are too large and prevent proper Solar Panel Clip installation
16 JULY 2010
Remove before flight pins (x2)
How is main unregula
ted power hooked up to battery board to deployment s
Order of the boards:
Where the 'spacer' are supplied in the cubesat kit.
Issue: The 'long spacer' is 60% longer than the supplied spacer from the Pro-E model however then the electrical connectors do not mate.
Issue: The RF connectors on the Radio board interfere with the RF connectors on the Antenna board.
Solutions could be:
1- rotation of the right angle radio board connectors
2- removal of one of the interfering connectors and leave other side connectorized on RF jumper
3- swap the order of the boards: swap TextSpk board with Radio board
4- ADD an extention connector that allows the use of the 60% longer spacer between the Radio and Antenna boards - this allows electrical connection and allows the SMA connectors to clear each other - this also centers the antenna board in the middle of the cubesat structure to align the antenna whips with the structure holes.
Issue: backside of solar panels (conductive) touch the structure. we must apply kapton tape to the structure prior to assembly.
Note: We must put all documents onto this wiki site. Keep all proprietary documents available to only login users.
Issue: the first prototype of the payload textspeak board showed too high of a profile - exceeding the distance of the spacer. It is thought that the flight boards for the TextSpeak payload board is a lower profile.
24 JULY 2010
completed battery board population on EDU board: all parts except batteries
assembled payload board on EDU - NOTE: R1 and R2 are jumpered with 0 ohm resistor to bypass, and therefore not require, the MAX232 driver chip. Since TextSpeak is only receiving the text string - the levels from the MSPF430F1612 is acceptable. AND it saves a few milliamps.
Still checking the RF interface between the Radio and Antenna boards:
A right angle SMA connector does not clear the Radio connectors. We may have to remove SMA and simply use dead-bug RF jumpers. [jrb]
Students Kristina, Alishan, Devan are assembling the solar array flash test cable today. This includes using an arduino (atmel) based uC to read the sensors on the solar array panels to read off voltage and current and temperature.
EDU ground station hardware is in place on the bench: PC<|>Kantronics 3+ modem<|>Kenwood TH-F6 (with 60db pad). We will go open air for testing rather than hardline.
With rumour of other cubesats failing vibration testing to Taurus PPOD levels, discussions on how to stake and conformal coat and stiffen the structure to survive vibration. (Hammond / Kemp)
The nitinol antenna wire does fit underneath the headers on the antenna board!
Radio to Antenna Board Spacing has a solution. By adding a spacer header connectors. However, we cannot use the same part number of samtec that the other boards use - the pins must be between 0.125" - 0.2" shorter. This works and has been implemented on the EDU cubesat today.
To make the flight units - we must order longer spacers than is supplied with the cubesat kit. These spacers must be 0.95" in length.
24 JULY 2010, 12:46, SUCCESS!
Cubesat stack is talking via RF to the ground station. (Just like at TJHSST). We now have a viable Engnineering Development Lab!
This means that all the student designed boards work well together.
Configuration notes: The Kenwood TH-F6 has a 30dB attenuator on the antenna. The Radio TX has 50dB attenuation. The Radio RX has 40dB attenuation. The ground station radio is .5 meters from the cubesat.
Software on the cubesat is queried via ground command over RF. Below is a snapshot of the ground terminal (raw data).
Note that the cubesat ID is KI4VUT. The test ground station is KA3BWT
KA3BWT>CQ: <UI>: ;02,xxxxxx;21; KI4VUT-1>CQ,TCPIP: <UI>: build:v1 TJ3SAT
We went out for pizza to celebrate.