Difference between revisions of "DFM-17 Radiosonde"

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(Added more pictures, pinouts of sensor stalk, identified ICs, peripheral attachment pinouts)
(Added IC Table and began to populate, added image with U ref designators assigned)
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==Peripheral attachment points==
 
==Peripheral attachment points==
  
==== LED's and Buttons ====
+
====LED's and Buttons====
  
* Button = PC8
+
*Button = PC8
* LED_Y = PC7
+
*LED_Y = PC7
* LED_G = PC6
+
*LED_G = PC6
* LED_R = PB12
+
*LED_R = PB12
  
==== GPS ====
+
====GPS====
  
* PA3(RX) = GPS TXD
+
*PA3(RX) = GPS TXD
* PA2(TX) = GPS RXD
+
*PA2(TX) = GPS RXD
  
==== UART via USB Port ====
+
====UART via USB Port====
  
* PA9(TX) = USB D+
+
*PA9(TX) = USB D+
* PA10(RX) = USB D-
+
*PA10(RX) = USB D-
  
==== Si4063 ====
+
====Si4063====
  
* PB2 = CS/nSEL
+
*PB2 = CS/nSEL
* PA7 = SDI
+
*PA7 = SDI
* PA6 = SDO
+
*PA6 = SDO
* PA5 = SCLK
+
*PA5 = SCLK
  
== Identified Supplementary IC's ==
+
==Identified Supplementary IC's==
 
'''V719''' = [https://www.mouser.com/datasheet/2/389/stg719-1850635.pdf STG719STR Low Voltage 4 Ohm SPDT Switch]
 
'''V719''' = [https://www.mouser.com/datasheet/2/389/stg719-1850635.pdf STG719STR Low Voltage 4 Ohm SPDT Switch]
  
Line 56: Line 56:
 
'''636EE''' = [https://www.mouser.com/datasheet/2/427/dg636e-1766306.pdf DG636EEQ Siliconix/Vishay Dual SPDT Switch]
 
'''636EE''' = [https://www.mouser.com/datasheet/2/427/dg636e-1766306.pdf DG636EEQ Siliconix/Vishay Dual SPDT Switch]
  
'''LW053A''' = [https://www.ti.com/lit/ds/symlink/sn74lv4053a.pdf Triple 2 Channel Analog Multiplex/Demultiplexer]<br />
+
'''LW053A''' = [https://www.ti.com/lit/ds/symlink/sn74lv4053a.pdf Triple 2 Channel Analog Multiplex/Demultiplexer]
 +
 
 +
<br />
 +
{| class="wikitable"
 +
|+
 +
!Ref Desig(s)
 +
!Manufacturer
 +
!Part Number
 +
!Description
 +
!Part Marking
 +
!Datasheet
 +
|-
 +
|U1
 +
|STMicroelectronics
 +
|STM32F100R8T6B
 +
|ARM MCU, 24MHz, 8KB RAM, 64KB Flash
 +
|
 +
|[https://www.mouser.com/datasheet/2/389/stm32f100cb-1851080.pdf Mouser]
 +
|-
 +
|U2, U3, U4, U5, U7
 +
|ST
 +
|STG719
 +
|STG719STR Low Voltage 4 Ohm SPDT Switch
 +
|V719
 +
|[https://www.mouser.com/datasheet/2/389/stg719-1850635.pdf Mouser]
 +
|-
 +
|U6
 +
|Vishay
 +
|DG636E
 +
|0.3 pC Charge Injection, 100 pA Leakage
 +
CMOS ± 5 V / 5 V / 3 V Dual SPDT Analog Switch
 +
|636EE
 +
|[https://www.mouser.com/datasheet/2/427/dg636e-1766306.pdf Mouser]
 +
|-
 +
|U7
 +
|Texas Instruments
 +
|SN74LV4053A
 +
|Triple 2-Channel Analog Multiplexer/Demultiplexer
 +
|LW053A
 +
|[https://www.ti.com/lit/ds/symlink/sn74lv4053a.pdf Texas Instruments]
 +
|-
 +
|U8
 +
|Texas Instruments
 +
|LMV761
 +
|Low Voltage Precision Comparator with Push/Pull Output
 +
|C22A
 +
|[https://www.ti.com/lit/ds/symlink/lmv762.pdf Texas Instruments]
 +
|-
 +
|U9
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U10
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U11
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U12
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U13
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U14
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U15
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U16
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|-
 +
|U17
 +
|
 +
|
 +
|
 +
|
 +
|
 +
|}
 +
<br />
  
 
==Photos==
 
==Photos==
Line 69: Line 180:
 
File:Stalk pinout mapping.png|Mapping of the pins on the sensor stalk to the connector and their corresponding IC/IO lines. '''''<u>Top of sensor stalk corresponds to bottom of pictured connector!</u>'''''
 
File:Stalk pinout mapping.png|Mapping of the pins on the sensor stalk to the connector and their corresponding IC/IO lines. '''''<u>Top of sensor stalk corresponds to bottom of pictured connector!</u>'''''
 
File:Dfm back pcb no battery.jpg|Back of the DFM PCB without CR123A battery holders
 
File:Dfm back pcb no battery.jpg|Back of the DFM PCB without CR123A battery holders
 +
File:DFM-17 Uref overlay.jpg|alt=PCB with reference designators|Top of PCB with U(*) Reference Designators overlaid ICs
 
</gallery>
 
</gallery>
  

Revision as of 23:32, 16 January 2023

The DFM-17 is a balloon-launched radiosonde manufactured by GRAW Radiosondes GmbH & Co. KG, and used for meteorological sounding.

The label side view of a DFM-17 Radiosonde


Overview

The DFM-17 radiosonde succeeds the DFM-09 radiosonde. Graw began a contract with NOAA in the US to provide radiosondes. As of Late 2021, several sites have made the transition as part of NOAA’s Operational Test and Evaluation (OT&E) program. 45 CONUS sites are expected to use these radiosondes in early 2022. [1]

Specs [2]

  • Weight: 63g
  • Size: 90 x 67 x 44 mm
  • Power supply: 2 CR123A batteries
  • Estimated runtime: ~240 minutes
  • Transmission rate: 1 packet/sec
  • Bandwidth: ~10 kHz (Website lists <12)
  • Frequency range: 400 - 405.99 MHz
  • Modulation: GFSK
  • TX Power: ~100mW
  • Error Correction: Code-spreading, interleaving
  • SoC: STM32F100R8T6B, 24MHz, 8KB RAM, 64KB Flash
  • GPS: U-Blox MAX-M8C-0-10
  • Transmitter: Si4063

Peripheral attachment points

LED's and Buttons

  • Button = PC8
  • LED_Y = PC7
  • LED_G = PC6
  • LED_R = PB12

GPS

  • PA3(RX) = GPS TXD
  • PA2(TX) = GPS RXD

UART via USB Port

  • PA9(TX) = USB D+
  • PA10(RX) = USB D-

Si4063

  • PB2 = CS/nSEL
  • PA7 = SDI
  • PA6 = SDO
  • PA5 = SCLK

Identified Supplementary IC's

V719 = STG719STR Low Voltage 4 Ohm SPDT Switch

C22A = LMV761 Low Voltage Precision Comparator with Push/Pull Output

636EE = DG636EEQ Siliconix/Vishay Dual SPDT Switch

LW053A = Triple 2 Channel Analog Multiplex/Demultiplexer


Ref Desig(s) Manufacturer Part Number Description Part Marking Datasheet
U1 STMicroelectronics STM32F100R8T6B ARM MCU, 24MHz, 8KB RAM, 64KB Flash Mouser
U2, U3, U4, U5, U7 ST STG719 STG719STR Low Voltage 4 Ohm SPDT Switch V719 Mouser
U6 Vishay DG636E 0.3 pC Charge Injection, 100 pA Leakage

CMOS ± 5 V / 5 V / 3 V Dual SPDT Analog Switch

636EE Mouser
U7 Texas Instruments SN74LV4053A Triple 2-Channel Analog Multiplexer/Demultiplexer LW053A Texas Instruments
U8 Texas Instruments LMV761 Low Voltage Precision Comparator with Push/Pull Output C22A Texas Instruments
U9
U10
U11
U12
U13
U14
U15
U16
U17


Photos

Disassembly


  1. Examine rope, parachute and parachute rigging lines for viability. Neatly organize the flight rigging if usable. Discard if not viable for reuse.
  2. Cut the zip tie surrounding the Styrofoam from the top portion by the rope loop.
  3. Pull the rope loop out, there should be little to no resistance.
  4. Make a slice in the sticker[4] where the two pieces of Styrofoam meet.
  5. Pull apart the two Styrofoam pieces to reveal the circuit board.
  6. Pull the circuit board out. There will be some resistance.
  7. The board is now separated from the Styrofoam shell, reuse if desired.
  8. Pull the two CR123A batteries out, keep or discard them. The board can run off USB power. Batteries are not necessary for development on this board.

Reassembly


  1. Insert two fresh CR123A batteries into the board.
  2. Line up the board to the IO cutouts in the Styrofoam, begin to push into the slots. Make sure the antenna wire comes through.
  3. Press the top piece of Styrofoam into place.
  4. Tape or apply another sticker onto the back label. (Optional)
  5. Insert the plastic rope loop piece.
  6. zip tie the shell together, the zip tie end should end up on the edge nearest to the power button.
  7. Rope on a balloon/drone/kite/etc.. to the rope loop.
  8. Power on the device by pressing and holding the button, you will see a yellow light blink, hold until the light turns solid.

Mini USB Port

The mini USB port on the board does not use the USB protocol for communication, it is a UART bus. However using USB to power the board should not harm the board in theory.

In order to use it, splice a USB cable and wire up a USB<->TTL adapter with the following pins:

  • VBUS: 5 Volts DC
  • D-: TX
  • D+: RX
  • GND: GND


The board will communicate with the official GRAWMET software using this approach. Reverse engineering of the port's protocol is underway, however it is believed to use a similar, if not the same protocol the PS-15 uses.

Hardware modifications

MrARM's modified DFM-17 with a SWD connector and a SMA antenna.

The DFM-17 has solder pads for an SMA port and a SWD header.

An Adafruit Skinny SWD SMT connector and a generic SMA connected was used in the photo.





Developing and Programming the board

A very crude diagram showing the standard SWD pinout overlaid onto the DFM-17 board


When lab testing, you can power the board from the USB header. It also appears to run fine supplying 3.3V to the SWD port(STLink clones do this).


The board uses a STM32, and requires a ST-Link to program. The process used to upload code to the MCU is the same as the Vaisala RS41 radiosonde, you will need to solder and connect the VTRef(3.3V), Ground, SWDIO, SWDCLK and RST pins to your ST-Link.

The board can run without external power being supplied when programming. This board has read-out protection enabled similar to the RS41 and this must be disabled before you can flash firmware to the board.