updated readme

Author: MaxBaex

pcb/README.md

@@ -1,68 +1,49 @@
-# Concept change
-- Enclosure change: 1455K1202 (120x78x43 space for DGNSS)  or 1455J1201 (120x78x27 for single GNSS)
-- Replace HM-19 Bluetoothmodule with a ESP32-WROOM-32U with external Antenna. Could even be used to flash the STM32F4 via WIFI. Connect STM32 UART, Boot-0 and Reset for Wifi flashing option. Attention: 400mA peak consumption in Wifi Mode. Example for WIFI / TCP: https://github.com/AlphaLima/ESP32-Serial-Bridge Connection of two smartphones simultaneously in a double seater is possible. 
-- Design milled static pressure hose connector. Concept Idea: Mounting holes 4x in 11.5mm distance square on the edge so that inner hoses are only required for pitot sensing?
-- U.FL for GNSS and Wifi/BT via external SMA-Pigtails.
-- USB-C connectors whereever possible. Vertical USB-C for GNSS somewhere on PCB
-- 2 RJ45 connectors. 1 for CAN/RS232 (selectable) 1 for RS232 
-- Redesigned 3.3VA supply with capacity multiplier and filtering.
-
-# TODOs Version 2.0
-- Finished!
-
-## Done
-- DONE: Larus Symbol on PCB
-- DONE: Separate Shield GND around the PCB connected with one ferrit to GND.
-- DONE: Thermal reliefs on copper fills. 
-- DONE: Added 3 mounting holes 0.8inch distance for sparkfun headers
-- DONE: MS5611 no routing not between pins!
-- DONE: Active current limiting of GNSS antenna feed with C8542 cuircuit taken from https://content.u-blox.com/sites/default/files/ZED-F9P_IntegrationManual_UBX-18010802.pdf
-- DONE: Added a LED to 3.3VA
-- DONE: ESD-diodes at voltage supply input and GNSS antenna.
-- DONE: changed ptc fuse with a suitable current 
-- DONE: Change RJ45 CAN pinout so that a real twisted pair is used.
-- DONE: Replace the diodes with a lower forward voltage ones.
-- DONE: Boost Converter to Boost USB Voltage: TPS61170DRVR Inductors: 10uH 1.5A: C340393, 
-- DONE: Move sd-card as far as possible to the pcb edge.
-- DONE: Redesign 3.3VA voltage supply with a separate LDO after the 5V Buck.
-- DONE: Filter C for R1 on DC-DC regulators: 15PF here: https://www.researchgate.net/figure/The-circuit-structure-of-the-MP2359-power-supply_fig24_330912026  Put a 0603 footprint. 
-- DONE: Check ferrit bead current rating. Saturation!
-- DONE: Remove cheap Gyro / ACC IMU as there will e.g. be a SparkFun 9DoF IMU Breakout. Keep expensive xSense Footprint.   
-- DONE: Add a switch for boot0 at the pcb edge. 
-- DONE: Add GNSS reset pullup resistor. 
-- DONE: At least add a 10uF, 100nF on voltage input and after buck converters.
-- DONE: Change name in schematic for gauge sensor to HSCMRRV001PG2A3 
-- DONE: Replace existing USART-3 connector with Pixhawk standard JST-GH 6 pin Connector to connect and supply simpleRTK2B+heading modules.  1: 5V_IN, 2: RX (3.3V level), 3: TX (3.3V level), 4,5: Not connected, 6: GND
-- DONE: Detect hardware version with an adc input. Might use new GNSS-Reset or CAN2 pullup? Check for missing GPS_RESET pullup to detect the first or newer version. Use ADC123_IN11 to distinguish between 2nd and future versions. 50% for 2nd version. 
-- DONE: Decrease testpoint size to 1mm
-- DONE: Sense supply voltage before ferit.
-- DONE: Remove one MS5611 sensor
-- DONE: change RJ45 connectors
-- DONE: u.fl connector
-- DONE: status led name labeling
-- DONE: Connect differential pressure supply to analog voltage and beautify schematic symbol. 
-- DONE: Connect USB, RJ45 schields and aluminium enclosure together (Shield_GND). Connect Shield_GND with ferrit to GND. 
-- DONE: Connect aluminium enclosure on one side to the PCB.
-- DONE: 7x C77096 (4.7u 1206 Package) on the input side of the Buck Converter. Remove 10uF and 22uF. 
-- DONE: Adjust R28 1k 5V Supply LED resistor.
-- DONE: Add ESP protection for CH340E USB connection
-- DONE: Add solder jumper (default closed) on CH340 TXD pin.   (Default shall be the USB connection) 
-- DONE: GNSS antenna connection on pcb is slightly above the critical length: https://www.youtube.com/watch?v=_Hfzq1QES-Q  Consider when changing to U.FL
-
-
-# Design decisions which wont be realized for version 2:
+# PCB Concept
+- Format to fit aluminium enclosure: 1455K1202 (120x78x43 space for DGNSS)  or 1455J1201 (120x78x27 for single GNSS)
+- ESP32-WROOM-32U for an improve connectivity. Could also be used to flash the STM32F4 via WIFI. Example for WIFI / TCP: https://github.com/AlphaLima/ESP32-Serial-Bridge connection. Simultaneously two smartphone connections in a double seater are possible via wifi. 
+- Footprint for a milled 5mm pressure hose connector on the edge.
+- U.FL connectors for GNSS and Wifi/BT antennas via external SMA-Pigtails.
+- USB-C connectors for GNSS, ESP32 and STM32
+- 2 RJ45 connectors for CAN and RS232
+
+# Changes done for Version 2.0
+- Changed the pcb format to fit the aluminium enclosure 1455K1202 or 1455J1201.
+- Redesigned the analog 3.3VA voltage supply with a capacity multiplier and a separate LDO after the 5V Buck converter.
+- Introduced a seperated analog section on the board and placed the regulator, filter and sensors there.
+- Replaced the bluetooth module with an esp32 for improved bluetooth and wifi connectivity.
+- Removed the low cost Gyro, Acc and Mag components and addded 3 mounting holes in 0.8inch distance for sparkfun headers.
+- Removed the second MS5611 and improved the layout.
+- Replaced the existing USART-3 connector with a Pixhawk standard JST-GH 6 pin Connector to connect and supply DGNSS simpleRTK2B+heading modules. 1: 5V_IN, 2: RX (3.3V level), 3: TX (3.3V level), 4,5: Not connected, 6: GND.
+- Changed to two single RJ45 connectors for CAN and RS232.
+- Added a footprint for a milled pressure hood including mounting screws to connect static and pitot on the pcbs edge.
+- Redesigned the digital voltage supply regulators and added sufficient capacity.
+- Added a separate boost converter to boost the USB Voltage.
+- Added a Larus Symbol on the board.
+- Changed the SMA to a u.fl connector for the GNSS Antenna.
+- Added active current limiting of GNSS antenna feed with circuit taken from the U-Blox F9P hardware integration manual.
+- Added ESD-protection diodes for voltage supply, GNSS antenna and USB connectors.
+- Added thermal reliefs on copper fills to improve hand solderability.
+- Added more status and error LEDs and labeling.
+- Connected USB, RJ45 shields and aluminium enclosure to a separate shield ground net. Routed the shield ground around the PCB and connected it on one point with a ferrit to ground. 
+- Changed the RJ45 CAN pinout so that a twisted pair of a standard patchcable is used.
+- Improved anti-alias filtering for supply voltage measurement.
+- Added a switch for boot0 at the pcb edge.
+- Added the missing GNSS reset pullup resistor.
+- Enabled detecting the hardware version with an adc input and a 1:1 voltage divider for this version.
+- Decreased testpoint size to 1mm
+
+
+# Ideas for next hardware iteration
 - User switch at the pcb edge.
 - A single sepic converster e.g. LM3488 for 3... 24V input  -> 5V output
 - Alternative Debug Connector TC2030-CTX-NL-STDC14 : https://www.tag-connect.com/solutions-target-devices/arm#s0
-- Sd-card power supply switchable
+- Sd-card power supply switchable.
 - 27R series resistors for sdio bus lines. 
 - Connect GNSS-PPS to GPIO timer input. 
-- Fuses between RJ45 12V connections. 
-- Change CAN1 to CAN2 so that the build in STM CAN-Bootloader can be used for flashing.
 - Sockets for 2 DGNSS modules: https://www.gnss.store/gnss-gps-modules/145-elt128.html,  https://www.ardusimple.com/product/simplertk2blite/
 
 
-## Links to parts
+# Links to some parts
 Gauge pressure: HSCMRRV001PG2A3
 https://de.farnell.com/honeywell/hscmrrv001pg2a3/drucksensor-1psi-i2c-digital/dp/3439040
 https://de.rs-online.com/web/p/drucksensor-ics/2269696