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===Peripheral attachment points===
[[File:Modified DFM-17 Radiosonde.jpg|thumb|332x332px|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.
<br />
Added possible LD series LDO data sheet
*Transmitter: Si4063
====LED's and Buttons==== *Button = PC8*LED_Y = PC7*U-Blox LED_G = PC6*LED_R = PB12 ====uBlox GPS is attached to (USART_2 on the STM32 via pins )==== *PA3(RX) = GPS TXD (Pin 2)*PA2 and PA3(TX) = GPS RXD (Pin 3)*External serial port PB8 = GPS 1pps (Pin 4) (USB LED next to flex cable connector) is attached to ====UART via USB Port (USART_1 )==== *PA9(PA9 and TX) = USB D+*PA10(RX)= USB D- ====Si4063 (SPI_1)==== *PB2 = CS/nSEL (Pin 15)*PC3 - SDN (Pin 1)*PA7 = SDI (Pin 14)*PA6 = SDO (Pin 13)*PA5 = SCLK (Pin 12) '''NFC/RFID 4k EEPROM''' *PC13 = RF WIP/Busy (Pin 7)*PB6 = SCL (Pin 6)*PB7 (''needs confirmed, sharing TXsignal routes under STM)'' = SDA (Pin 5) '''STG719 (DPST) - U2''' *PC11 = IN (Pin 1) '''STG719 (DPST) - U3''' *PD2 = IN (Pin 1) '''STG719 (DPST) - U4''' *PB5 = IN (Pin 1) '''STG719 (DPST) - U5''' *PB4= IN (Pin 1) '''DG636 (Dual DPST) - U6''' *VDD = ENABLE (always HIGH) (Pin 2)*PA10 = A0 (Pin 1)*''UnknownPin#1'' (routes under STM) = A1 (Pin 14) '''STG719 (DPST) - U7''' *''UnknownPin#1'' (routes under STM) = IN (Pin 1) '''SN74LV4053 (Triple 2Ch Mux/Demux) - U8''' *PB13 & PB14 = A (Pin 11)**STM pins connected by trace? ''Why? Read back?''*''UnknownPin#1'' (routes under STM) = B (Pin 10) & C (Pin 9)**IC pins connected by trace '''Analog Inputs to STM2''' *PA0 - Vbatt/Power supply voltage (''needs confirmation)''*PB1 - Vbatt/RX with the external I²C bus.Power supply current monitor (''needs confirmation)''
<br />
==Identified Supplementary IC's==
<gallery>
File:DFM-17 Uref overlay.jpg|alt=U reference designators overlaid|Top view of PCB with U reference designators overlaid
</gallery>
{| class="wikitable"
|+
IC Part Numbers and Markings
!
!Manufacturer
!Part Number
!Description
!Package
!Part Marking
!Datasheet
!Note
|-
|U1
|STMicroelectronics
|STM32F100R8T6B
|ARM MCU, 24MHz, 8KB RAM, 64KB Flash
|LQFP48
|ARM 32F100R8T6B
|[https://www.mouser.com/datasheet/2/389/stm32f100cb-1851080.pdf Mouser]
|''Some recent batches of the DFM-17 have been using knockoff STM32s! The chip shortage strikes again!''
|-
|U2, U3, U4, U5, U7
|ST
|STG719
|STG719STR Low Voltage 4 Ohm SPDT Switch
|SOT-23-6
|V719
|[https://www.mouser.com/datasheet/2/389/stg719-1850635.pdf Mouser]
|''Analog ADG719 pin compatible equivalent?''
|-
|U6
|Vishay
|DG636E
|0.3 pC Charge Injection, 100 pA Leakage
CMOS ± 5 V / 5 V / 3 V Dual SPDT Analog Switch
|TSSOP14
|636EE
|[https://www.mouser.com/datasheet/2/427/dg636e-1766306.pdf Mouser]
|
|-
|U8
|Texas Instruments
|SN74LV4053A
|Triple 2-Channel Analog Multiplexer/Demultiplexer
|SOT-23-6
|LW053A
|[https://www.ti.com/lit/ds/symlink/sn74lv4053a.pdf Texas Instruments]
|
|-
|U9
|Texas Instruments
|LMV761
|Low Voltage Precision Comparator with Push/Pull Output
|SOT-23-6
|C22A
|[https://www.ti.com/lit/ds/symlink/lmv762.pdf Texas Instruments]
|
|-
|U10
|Silicon Labs
|Si4063
|High Performance, Low Current Transmitter
|QFN20
|40632A
C01Q81
2217
|[https://www.silabs.com/documents/public/data-sheets/Si4063-60-C.pdf Silcon Labs]
|
|-
|U11
|u-Blox
|MAX-M8C-0-10
|u-blox M8 GNSS module, ROM, crystal
|
|MAX-M8C-0-10
|[https://www.u-blox.com/sites/default/files/MAX-M8-FW3_DataSheet_%28UBX-15031506%29.pdf u-Blox]
|
|-
|U12
|STMicroelectronics
|M24LR04E-R
|Dynamic NFC/RFID tag IC with 4-Kbit EEPROM,
energy harvesting, I²C bus and ISO 15693 RF interface
|UDFN8
|4BEB 8150
|[https://www.st.com/resource/en/datasheet/m24lr04e-r.pdf STMicroelectronics]
|''Needs verification. DFM-17 does not boot when removed; I suspect the serial and calibration is stored in the EEPROM here - Trevor229''
|-
|U13
|STMicroelectronics
|LD series, ''unsure on specific part''
|3.3V Low Drop Out Voltage Regulator
|DFN6
|33R
|[https://www.mouser.com/datasheet/2/389/ld39050-1849494.pdf Possible part from Mouser]
|''Needs verification, appears to provide 3.3V regulated power''
|-
|U14
|
|
|
|
|
|
|''Looks like a high side current monitor amplifier, need more information''
|-
|U15
|ABLIC
|S-8200A Series, ''unsure on specific Part Number''
|BATTERY PROTECTION IC FOR 1-CELL PACK
|
|VDL
|[https://www.mouser.com/datasheet/2/360/S8200A_E-1365901.pdf Mouser]
|''Needs verification, Potentially a Winsok WSTDW01 Battery Protection IC?''
|-
|U16
|
|
|
|
|AL
W24
|
|''In-line with battery power, need more information; chip marking''
|-
|U17
|
|
|
|
|
|
|''Connected to USB data lines, likely a UART, isolation, and/or level shifter''
|}
<br />
File:Label id speculaton.jpg|Possible meanings of the internal labels and values. The date code in particular which may be useful to date production times. NWS sondes have the same cryptic string printed on the outside of the sonde where the mfg. date normally is on other countries'. "TU" may just indicate the board comes with sensors according to a third party source<ref>https://sondehunt.de/language/en/archive/1189</ref>.
File:Sensor stalk pinout.jpg|Pinout of the DFM-17 sensor stalk. Not all pins are used, and some seemingly are connected to a trace but end abruptly.
File:V719 and others removed.jpg|V719 SOT-23-6 packages removed as well as 636EE (SPDT Switch) and LW053A (Mux/Demuxer)
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
</gallery>
==Hardware modifications==
====SMA Port to replace antenna & SWD header:====The DFM-17 has solder pads for an SMA port and a SWD header. An [https://adafru.it/4048 Adafruit Skinny SWD SMT] connector and a generic SMA connected was used in the photo.
====Minimizing transmit range:====
As amateurs we are not licensed to transmit in the 400-406MHz band, so for testing purposes one should perform this mod. Unsolder the antenna wire and take two 100 ohm resistors and twist them in parallel, then solder them to the center pad and one of the side pads on the SMA footprint. This creates a 50 ohm dummy load for the Si4036 to transmit into. The range is reduced to a couple tens of feet. Also if you are running a radiosonde_auto_rx instance, don't forget to turn it off during testing to avoid feeding erroneous data to Sondehub!<gallery>
File:Modified DFM-17 Radiosonde.jpg|MrARM's modified DFM-17 with a SWD connector and an SMA antenna port
File:Dfm 17 swd and resistors.jpg|Trevor229's DFM with ST-Link SWD pins connected to debug interface and 50 ohm dummy load mod.
</gallery>
==Developing and Programming the board==
[[File:DFM-17 SWD Port pinout.png|thumb|A very crude diagram showing the standard SWD pinout overlaid onto the DFM-17 board]]
