Balloons Gen 1 Breakout

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Viper
Part of the HONEY Architecture series
& the HABEES series
Chief Designer Kirill Safin
Technology Line Balloons Breakouts
Version Generation I
Name Viper
General
HONEY Standards Venom Breakout Fang Breakout Board Naming
Core Software
STINGR
Core Avionics
The Count
Core Power
Biscuit
Core Peripherals
Cobra Viper ProtoBee
Core Radio
Macaw
Test & Prototype
QueenBee
Guides
Making a HONEY Board Using STINGR Using QueenBee Making a Prototype
VE

Viper is the first generation HONEY Breakout Board. Viper breaks out most of the important signal and power lines from the HONEY stack Data Bus & Power Bus, as well as the CAN Bus, to enable connecting to the HONEY flight stack remotely, over cable.

As of August 10th, 2017, all HONEY flight stacks require Viper as the bottom-most (stack-terminating) board. This makes Viper a FCC (Flight Critical Component). This is both for physical and electrical reasons -- Viper is the only board with a non-stackthrough data bus, making it the choice for the bottom-most board. This was previously the BMS, due to the need for enough space for the battery pack -- however, the maximum spacing between flight stack boards has since increased to 20mm, allowing the BMS to be on the stack interior, and necessitating an alternate stack-terminating board -- Viper was chosen. Necessarily having Viper in a Flight Stack also guarantees any stack can be debugged using the master breakout, or expanded using payload breakouts.

This enables two important capabilities, such as:

  • The Flight Stack can be broken into two compartments, and connected seamlessly via cable, continuing to act as one complete flight stack (unless there are relevant data bus signals that aren't broken out).
  • The Flight Stack can be broken out to an external payload, which, with the correct receiving connector, can have access to all of the stack data/power/signal lines. This enables using the HONEY flight stack for non-HONEY payloads -- such as ProtoBee's or similar projects.

These functions, as well as a breakdown of the Viper Breakout Pinout, are explained below:

Pinout

Viper comes with three connectors -- two "Payload Breakouts" and one "Master Breakout". They are discussed in detail below.

Payload Breakout

Viper has two Payload Breakout connectors -- this allows for the possibility of daisy chaining vertically or horizontally through the same flight stack. That is, you can "extend" the flight stack downward by having another flight stack below it, connected to the original flight stacks Viper boad, AND simultaneously extend the flight stack vertically, by adding a flight stack above the original flight stack, and connecting it to the other payload breakout.

The Payload Breakout format (meaning, the particular connector, cabling) as well as the specific pinout, is called Venom Breakout.

There is no need for more than two payload breakouts, with the expectation that all boards that receive the payload breakout also have a secondary connector to allow for continued daisy chaining. This is the case, for example, on ProtoBee.

The particular payload breakout itself is a 1.27mm pitch 2x25 pin keyed, shrouded connector. This decision was made to make the breakout as small as possible, and keep the cabling thin. The exact connector, and associated cabling, are:

Connector: [| Samtec SHF-125-01-L-D-RA] Cabling: Samtec FFSD-25-D-XX.XX-01-N

In the above, XX.XX denotes the length -- which can be custom as desired, in inches (2 inch minimum).

The specific pin out for Venom Breakout is the following, with the first row as the top, second row as the bottom, left to right as seen looking into the receptacle from the board-edge.

5V 3.3V BUS VBATT (4.2V) 12V 1.8V SDA SCL MOSI MISO SCLK VA_PWM CHIRP R_MCU R_ALL S_READY LOW_PWR FMODE SYS_F3 SYS_F4 SYS_F5 SYS_F6 (+5 S) (-5 S) CAN_SPD GND
5V 3.3V BUS VBATT (4.2V) 12V VADJ OUT TX4 RX4 TX6 RX6 DAC0 DAC1 AV29 AV42 AV17 AV16 AV35 AV36 AV37 AV38 CAN1_H CAN1_L (+12 S) (-12 S) 3.3V CAN GND

Master Breakout

In addition to the Venom Breakout, Viper also includes a larger, 56-pin 2.54mm (standard) pitch connector known as the Master Breakout -- or, more formally, the Fang Breakout.

The Fang Breakout breaks out the remainder of what the Viper Breakout was unable to breakout, or what was deemed inessential for a payload to have access to. This includes the secondary CAN Bus and some additional avionics GPIO pins.

The connector and associated cabling are: Connector: Samtec TST-156-01-F-D-RA Cabling: HCSD-28-D-XX.XX-01-S-N-G

The Fang Breakout, at time of writing (Aug 10, 2017) has no impending implementation scheme. It exists in the first revision of the HAB Breakout to facilitate two things -- one, the possible eventual need to break out the additional remaining pins, and, more importantly, two -- to enable directly using female jumper wires to tap signals directly from Viper, by providing a standard-pitch connector that can be both directly tapped or cabled.

The Fang Breakout pinout is very similar to the Venom Breakout, with some slight alterations:

5V 3.3V BUS VBATT (4.2V) 12V 1.8V SDA SCL MOSI MISO SCLK VA_PWM CHIRP R_MCU R_ALL S_READY LOW_PWR FMODE SYS_F3 SYS_F4 SYS_F5 SYS_F6 CAN2_H CAN2_L (+5 S) (-5 S) (+12 S) (-12 S) GND
5V 3.3V BUS VBATT (4.2V) 12V VADJ OUT TX4 RX4 TX6 RX6 DAC0 DAC1 AV29 AV42 AV17 AV16 AV35 AV36 AV37 AV38 AVA10 AV51 AV52 AV53 CAN1_H CAN1_L CAN_SPD 3.3V CAN GND