SMD Wing - arribada/featherwings-argos-smd-hw GitHub Wiki

General

Overview

The SMD Wings board provides a complete solution for satellite uplink development. It comes with the SMD Module pre-soldered and pre-flashed with the latest firmware, ensuring out-of-the-box functionality. Its Feather-compatible design enables rapid prototyping by seamlessly integrating with Feather boards, while streamlined testing offers reliable Argos SMD connectivity. Designed with production in mind, this board makes it easy for developers to transition from prototyping to full-scale manufacturing with minimal changes.

This board is fully-certified by CLS/CNES and can communicate with satellites with just a valid ID—simply request your ID from CLS and upload it to the board using an AT command.

This board is dedicated for use with Adafruit Feather boards and has been thoroughly tested with the nRF52840 Feather.

Versions

Version managed by git repository under Releases and Tags.

Latest (02/2025):

  • V1.0 production (branch breakout-v1.0)

Hardware

Technical Specifications

  • Dimensions: 51x30 mm, 7grams
  • Power Supply Voltages provided by Feather board:
    • Powered by USB or Battery required for Uplink.
    • System voltage (3,3V) required for core operation .
  • Tested with the nRF52840 Feather board, enabling bluetooth communication
  • Reference design for power amplifier dedicated LDO
  • u.FL and pi-filter defined.
  • Integrated programmer
  • Pinout with easy connection with Serial/Uart for KimGUI communication

Block diagram

Below is a brief explanation of the block diagram for the Wings-SMD board. The dotted lines represent optional test connections that can be used during development or debugging:

  • External VPA Header (J5): Provides an optional way to test the VPA power supply for the power amplifier.
  • Debugger Connector (J6): An additional header for easy serial/USB connections, allowing use of CLS’s KimGui software for AT command testing.
  • Qwiic I2C Connector (J7): Enables the addition of other I2C devices or peripherals to the system.
  • Feather Headers (J1 & J3): These connect the Wings-SMD board to an Feather board.

Power requirements

Thanks to the Feather board no external power is required to work with the Wings-SMD, only a battery or an USB cable connected to the Feather board is sufficient. Check power management of nRF52840.

However, it can still operate without one if the user provides 3.3 V on pin J3-2, GND on pin J3-4, and VBAT (J1-1) and/or USB (J1-3). The 3,3V required for the Argos-SMD VDD is extracted from the power convertissor of the Feather board. The power of the Amplifier is extracted thanks to the TPS63901.

The TPS63901 is a buck/boost converter with a 75 nA quiescent current, supporting input voltages from 1.8 V to 5.5 V. It provides two possible output voltages based on the SEL pin state. By default, it supplies 3.3 V at up to 400 mA when SEL is pulled high. If SEL is pulled low, the output voltage switches to 1.8 V. The SEL pin could be managed by the SMD module thanks to the pin GPIOC1 or via the Feather board with the pin D11.

To change the secondary (low) output voltage, adjust R27 according to the required value as specified in the datasheet. For proper transmission, keep SEL high to maintain a 3.3 V output.

Note: In the schematic, the SEL pin is incorrectly labeled as PGOOD and should be updated to reflect its actual function.

The converter typically takes about 2.375 ms to ramp up to 3.3 V during soft-start.

Pinout

Each pin from the Feather headers is routed through a 0-ohm resistor, and by default only the UART and WAKEup signals are actively connected. The Feather interface also supplies 3.3 V power to the board and provides access to either USB or battery voltage. The following image shows the pinout of the Adafruit Feather nRF52840 used for the test and the link with the with Wings-SMD. NM = Not Mounted.

Programming

The Wings-SMD, combined with the SMD module, is pre-programmed with the argos-smd-at-kineis-firmware. Currently, to program or update the SMD module through the Wings-SMD, a TC2030-NL (No Legs) connector is required. This connector must be attached to a compatible programmer, such as the J-LINK Edu Mini or an ST-LINK. During development, a TC2030 clip can be used to keep the programmer securely in place.

Firmware

More details about how the firmware works can be found in the dedicated Wiki page of the repository. Includes:

Software

Includes:

  • CLS KimGUI interface (ask to CLS), software to communicate with AT command to the SMD module

    • Version >= 4.1.2

  • CLS Emulsat (ask to CLS), software dedicated to test the communication with Adalm-PLUTO SDR

    • Version >= 0.9