Iridium SBD communication for sending telemetry over a RockBLOCK module

[ivogeorg]

Description

The primary ground communications channel for the balloonsat is the Iridium satellite constellation through the RockBLOCK short-burst-data messaging modules. Since the packet size is 340 downlink and 270 uplink, this channel is only good for telemetry and control (insofar a balloonsat can be controlled). With clear sky, a message can be sent about every 10 seconds.

We have two versions of the RockBLOCK:

1. The 9602 or v2
2. The 9603 or v3, which is preferred due to lower weight and other improvements.

The PRi will connect to the RockBLOCK with a USB cable. V2 requires an external USB-to-Serial chip. V3 might have that internally.

Use RockBLOCK short burst messages to deliver live telemetry. In particular:

1. Connect to RPi and get the RockBlock library running
2. Write program to Schedule and queue messages per type and subsystem
3. Set up the msusat.org website and a Web service to show the telemetry.
4. Set up redirect to the Web service at msusat.org

Knowledge

1. 9603 vendor product page, specs, and docs
2. RockBlock guide. In particular:
   1. What's RockBLOCK.
   2. Integration with application
   3. Short burst data.
   4. Receiving data.
   5. RockBLOCK data cycle.
   6. Data compression.
3. RockBLOCK API reference. In particular:
   1. Sending MT messages. MT messages are ground/web service to RockBLOCK.
4. FTDI USB-to-Serial drivers
5. Simple message tutorial (DOES NOT WORK)
6. SparkFun video demo for connection from laptop.
7. Adafruit and CircuitPython (On Wikipedia):
   1. 9603 product page and user guide.
   2. Adafruit CircuitPython RockBLOCK library/driver on Github and ReadTheDocs.
   3. Raspberry Pi example with RockBLOCK and driver.
   4. CircuitPython releases and libraries.
   5. The Adafruit library depends on Adafruit-Blinka (PyPi and Github).
8. iridium AT Command Reference.

Deliverables

1. A driver library for the RockBLOCK in the form of a Python package. Managed by the Flight Executive (See #28).
2. Minimal functions:
   1. Send periodic telemetry (See #3).
   2. Accept and send asynchronous critical alerts.
   3. Priority message queue.
   4. Check for incoming messages (aka check mailbox). The incoming (MT) messages have to be retrieved by the RockBLOCK. TODO: Is there a PUSH mechanism that can be configured?
   5. Check and report status of Iridium connection.
   6. Acceptance tests:
   7. Check RPi-RockBLOCK connection (indoors). (AT --> OK)
   8. Round trip to ground with UPS and voltage and current sensor data (outdoors, on ground).
   9. Periodic telemetry after power up from inside battery-powered enclosure (outdoors, on ground).
   10. Periodic telemetry after power up from inside battery-powered enclosure (outdoors, in the air).

[ivogeorg]

We have 3 RockBLOCKs, one mine, and two from Randy. Randy says we can add his to my account. Need to ask Kate to buy credit.

[ivogeorg]

What to send:

1. Processor level of utilization (@ target of 80% continuous).
2. Processor internal readings (temperature, etc.).
3. Ambient temperature in box.
4. Altitude.
5. GPS coordinates.

@dperry29, @NotfatPrince, anything else?

[ivogeorg]

USB to Serial converters

For verifying RockBLOCK operation with a laptop.

1. SparkFun FT231X Breakout (BOB-13263):
   1. Defaults to 5 V (needs jumper soldering).
   2. No headers.
   3. USB, Micro B.
2. SparkFun FTDI Basic Breakout - 5V (DEV-09716):
   1. Defaults to 5 V. Jumper soldered to 3.3 V.
   2. USB, Mini B.
3. SparkFun Serial Basic Breakout - CH340C and USB-C (DEV-15096):
   1. Defaults to 3.3.
   2. USB, C.
4. SparkFun Cerberus USB Cable - 6ft (CAB-12016).

[NotfatPrince]

Description

1. Get the RockBlock library running
2. Schedule and queue messages per type and subsystem
3. Pack and encrypt data (encrypted text should be in ASCII) MSUSAT/Systems#2

   Knowledge

   RockBlock guide Drivers Simple message tutorial

Deliverables

For Indoor lab test of the system

• The RockBlock should communicate with the the RPi (We won't be able to send messages from indoors)
• The RockBlock should receive data packages from RPi and send an acknowledgement that data has been received

For outdoor lab test of the system. No box.

• The RockBlock should be able to send scheduled messages with data from the sensorium and internal telemetry.

[ivogeorg]

Sending a message AT commands

AT (testing device status) OK AT&KO (ready to send short-burst data) OK AT+SBDWT=Message to send (writing the message) OK AT+SBDIX (send message in buffer) +SBDIS: 0, 4, 0, 0, 0, 0 (upon successful transmission) +SBDIS: 32, 4, 2, 0, 0, 0 (upon failed transmission) OK

[ivogeorg]

[ahmedjazeera11]

"Connect to RPi and get the RockBlock library running" issue solved

[ahmedjazeera11]

DSD TECH 2PCS USB to TTL Serial Adapter with CP2102 Chip Compatible with Windows 7,8,10,Linux,Mac OS X https://www.amazon.com/gp/product/B078W5L8W1/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

[ivogeorg]

Iridium application

[ivogeorg]

Critical alerts from flight executive

[ivogeorg]

@nmead1 Read through this issue and let's discuss. This will feel like drinking from the hose, but don't worry. Tomorrow, I can give you a RockBLOCK to play with.

[ivogeorg]

The RPi setup for using the UART for the RockBLOCK specifies to enable Serial but disable Serial Console. In reference to #30, could both be enabled?

[ivogeorg]

The rockblock_simpletest.py works with Serial on and the following code:

# uart = board.UART()
# uart.baudrate = 19200

import serial
uart = serial.Serial("/dev/serial0", 19200)

Temperature fell under 0 degrees Celsius and could not run the rockblock_sendtext.py and rockblock_senddata.py.