Difference between revisions of "LMS-6 Radiosonde"

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(Connector table cleanup)
(→‎Connectors: I added some observations to the connectors from oscilloscope probing)
Line 100: Line 100:
 
!Pin Number
 
!Pin Number
 
!Function
 
!Function
 +
!Notes / Observations
 
|-
 
|-
 
|1,2,7,8
 
|1,2,7,8
 
|<nowiki>U3 - Vdd | U15 - Pin 4</nowiki>
 
|<nowiki>U3 - Vdd | U15 - Pin 4</nowiki>
 +
|
 
|-
 
|-
 
|9, 10, 15, 16, 19, 20, 33, 34
 
|9, 10, 15, 16, 19, 20, 33, 34
 
|Ground
 
|Ground
 +
|
 +
|-
 +
|2, 8, 18*, 24, 30
 +
| +5VDC
 +
|18 needs more research, may occasionally drop to ground?
 
|-
 
|-
 
|3
 
|3
 
|<nowiki>U3 - ICCLK | TP33 | U21 - PCLK</nowiki>
 
|<nowiki>U3 - ICCLK | TP33 | U21 - PCLK</nowiki>
 +
|
 
|-
 
|-
 
|4
 
|4
 
|U3 - Vpp/ICCSEL
 
|U3 - Vpp/ICCSEL
 +
|
 
|-
 
|-
 
|5
 
|5
 
|U3 - RESET
 
|U3 - RESET
 +
|
 
|-
 
|-
 
|6
 
|6
 
|U3 - ICCDATA
 
|U3 - ICCDATA
 +
|
 
|-
 
|-
 
|11
 
|11
 
|J5 - Pin 2
 
|J5 - Pin 2
 +
|
 +
|-
 +
|12
 +
|
 +
|3.3v - 2.5KHz square wave (4msec p/p)
 
|-
 
|-
 
|13
 
|13
 
|U3 - SW1.4
 
|U3 - SW1.4
 +
|
 
|-
 
|-
 
|17
 
|17
 
|U3 - SW1.2
 
|U3 - SW1.2
 +
|
 
|-
 
|-
 
|18
 
|18
 
|U3 - SW1.1
 
|U3 - SW1.1
 +
|
 +
|-
 +
|23
 +
|
 +
|Rounded-square wave data bursts
 +
|-
 +
|26
 +
|
 +
|Rounded-square wave data bursts
 
|-
 
|-
 
|31
 
|31
 
|BATT POS
 
|BATT POS
 +
|
 
|-
 
|-
 
|36
 
|36
 
|U3 - SW1.3
 
|U3 - SW1.3
 +
|
 
|-
 
|-
 
|38
 
|38
 
|U3 - OCMP1_A / AIN10 / PF4
 
|U3 - OCMP1_A / AIN10 / PF4
 +
|Square wave data bursts, 0.2msec per bit
 
|-
 
|-
 
|39
 
|39
 
|RED WIRE
 
|RED WIRE
 +
|
 +
|-
 +
|40
 +
|Battery voltage
 +
|Around 9VDC measured
 
|}
 
|}
  
Line 194: Line 229:
 
!Pin
 
!Pin
 
!Use
 
!Use
 +
!Notes/Observations
 
|-
 
|-
 
|1
 
|1
−
|Unknown
+
| +5VDC
 +
|
 
|-
 
|-
 
|2
 
|2
 
|Unknown
 
|Unknown
 +
|3V rounded square pulses, 2x per second, 2 different periods avg ~75msec?
 
|-
 
|-
 
|3
 
|3
−
|Unknown
+
| +5VDC
 +
|
 
|-
 
|-
 
|4
 
|4
 
|Unknown
 
|Unknown
 +
|5V, 0.1msec pulse once per second
 
|-
 
|-
 
|5
 
|5
−
|Unknown
+
| +5VDC
 +
|
 
|-
 
|-
 
|6
 
|6
 
|Unknown
 
|Unknown
 +
|5V, 0.1msec pulse once per second
 
|-
 
|-
 
|7
 
|7
−
|Unknown
+
| +5VDC
 +
|
 
|-
 
|-
 
|8
 
|8
 
|Unknown
 
|Unknown
 +
|3V, 250msec pulse once per second
 
|}
 
|}
 
These traces go to U14 (SPI mem?)
 
These traces go to U14 (SPI mem?)

Revision as of 05:05, 5 September 2020

The LMS-6 Radiosonde is a radiosonde manufactured by Lockheed-Martin Sippican, and used for meteorological sounding.


Overview

There are two models of the LMS-6, a 403MHz model and a 1680MHz model. This article will cover the 403MHz model unless specified.

Specs

  • 16 Fixed transmit carrier frequencies (MHz): 400.250, 400.625, 401.000, 401.375, 401.750, 402.125, 402.500, 402.875, 403.250, 403.625, 404.000, 404.375, 404.750, 405.125, 405.500, 405.875
  • Frequency tolerance +/-30ppm
  • Mean TX Power 70.8mW (18.5dBm)
  • Emission Designator 16K8F1D
  • FSK with a maximum modulating frequency of 4.8 kHz
  • Emission 3dB BW +/-5.0 kHz
  • Emission 20dB BW +/-12.7 kHz
  • Omnidirectional antenna
  • Main beam gain 2dBi
  • Horizontal Beamwidth 360 degrees
  • Vertical Beamwidth +84 degrees

Source: https://apps.fcc.gov/els/GetAtt.html?id=121623&x=.

Photos

Relative Humidity Circuit section




Connectors

There are four sensor connectors (SENSN) used for sensor input by the radiosonde. SENS1 is not populated on the 403MHz units. SENS2-4 have leads connected to them, and the sensors are connected to the other end of the leads, outside of the radiosonde housing. Only SENS1 appears to have spacing for a connector; the others have arbitrary lead spacing.

SENS1 - 7-pin, 0.1" header spacing
Pin Characteristics
1 +5V (5.47 measured)
2 GND?
3 +4.93V (Microcontroller VCC?)
4 1 Hz
5 1 Hz
6 1 Hz
7 GND?

Public information shows this header can be used for adding additional analog sensors to the radiosonde.

SENS2 - Humidity
Pin Connection
1 Sensor pin 1
2 Sensor pin 2

0.3" spacing. Both lead wires have ferrite beads immediately before connecting to the board.

SENS3 - Temp. Sensor (standalone)
Pin Connection
1 Sensor pin 1
2 Sensor pin 2

0.5" spacing.

SENS4 - Temp. Sensor (humidistat)
Pin Connection
1 Sensor pin 1
2 Sensor pin 2

0.3" spacing. Fine gauge insulated wire run along SENS3 wire and loomed in white heat-shrink tubing.

Card edge - 40-pin, looks like ISA spacing
Pin Number Function Notes / Observations
1,2,7,8 U3 - Vdd | U15 - Pin 4
9, 10, 15, 16, 19, 20, 33, 34 Ground
2, 8, 18*, 24, 30 +5VDC 18 needs more research, may occasionally drop to ground?
3 U3 - ICCLK | TP33 | U21 - PCLK
4 U3 - Vpp/ICCSEL
5 U3 - RESET
6 U3 - ICCDATA
11 J5 - Pin 2
12 3.3v - 2.5KHz square wave (4msec p/p)
13 U3 - SW1.4
17 U3 - SW1.2
18 U3 - SW1.1
23 Rounded-square wave data bursts
26 Rounded-square wave data bursts
31 BATT POS
36 U3 - SW1.3
38 U3 - OCMP1_A / AIN10 / PF4 Square wave data bursts, 0.2msec per bit
39 RED WIRE
40 Battery voltage Around 9VDC measured
J1 - 4-pin, 0.1" header spacing
Pin Wire Color Use
1 Black Ground
2 White Battery +9
3 Red +9 VDC In
4 NC Unknown - goes to

unpopulated CR1


J4 - NC - earphone jack? uses SENS3 leads

J5 - 4-pin, 2.0mm spacing
Pin Use
1 Unknown
2 Unknown
3 Unknown
4 Unknown

These traces go to U3 (ST microcontroller)

SP1 - 2x4-pin, 0.1" spacing
Pin Use Notes/Observations
1 +5VDC
2 Unknown 3V rounded square pulses, 2x per second, 2 different periods avg ~75msec?
3 +5VDC
4 Unknown 5V, 0.1msec pulse once per second
5 +5VDC
6 Unknown 5V, 0.1msec pulse once per second
7 +5VDC
8 Unknown 3V, 250msec pulse once per second

These traces go to U14 (SPI mem?)

Components

GPS - Trimble 63530-50 s/n 1190122906

   https://www.trimble.com/embeddedsystems/copernicus2.aspx


U3 - 72F324J6T6 - ST72324 - Main Microcontroller, ST7 series

U5, U6 - LP2985

U?? - TPS7201Q

TPS7201Q on PCB

U13 - CD4040BPW

U14 - CD74HC4051PWR

U16 - LMV761

U21 - TI/Chipcon CC1050 (TSSOP 24)

U22 - TPS791


Sens 4 - Capacitive Relative humidity sensor

Notes

U13 Package marking shows CM040B. TI Park marking lookup provides CD4040BPW

U16 Package marking shows C22A. TI Part marking lookup provides LMV761. The SOT-23 footprint appears to match what is on the PCB.

Sens 4 is know to be capacitive since it is listed as such on page 13 of the WMO Common Code Tables Document

Circuits

RF from CC to Ant1 - coming soon


Relative Humidity Circuit

File:Relative Humidity Circuit Schematic.pdf U16 -Input also has a cap to ground not shown on the sketch.

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