iot-contact/pcb/processor.kicad_sch, branch mdnsIoT device to check if doors and windows are closed or openhttps://cgit.xengineering.eu/iot-contact/atom?h=mdns2025-08-10T15:36:15Zpcb: Place test points2025-08-10T15:36:15Zxengineeringme@xengineering.eu2025-08-10T15:36:15Zurn:sha1:c50d7275a98c420506c1be35d1c067394af700f5
They should be used to easier connect cables to the board to debug
hardware or firmware issues.
pcb: processor: Fix missing pull-up on STM32 RESET2025-07-27T16:09:30Zxengineeringme@xengineering.eu2025-07-27T16:09:30Zurn:sha1:2a3432a2195260f436c50e891e2e9b9a615dc670
This is a significant design bug which would leave the RESET line of the
MCU in a floating state. Thanks to ERC this is detected early.
pcb: Fix +3V3 and +3.3V confusion2025-07-27T16:01:47Zxengineeringme@xengineering.eu2025-07-27T16:01:47Zurn:sha1:514352748fee605be176e2f37dd9b12047458503
ERC brought up that those two global power labels were mixed. This is of
course a design bug which is now fixed by consistently using +3.3V.
pcb: power: Add `PWR_FLAG` symbols2025-07-25T20:25:27Zxengineeringme@xengineering.eu2025-07-25T20:02:41Zurn:sha1:d3e7f19f1f87b03e9a7c8a170b9c4351ac565268
This resolves ERC issues. The ERC complains that an power input is not
fed by a power output if there is a component like a ferrite bead or 0
Ohm resistor between the two.
The `PWR_FLAG` tells the ERC that it was explicitly checked that this is
not a mistake.
pcb: Reset part annotations2025-07-25T16:21:10Zxengineeringme@xengineering.eu2025-07-25T16:21:10Zurn:sha1:68d56b6f8e1abeaaa6982245bb73e9f9d712b44cpcb: processor: Add MAC EEPROM2025-07-25T15:24:43Zxengineeringme@xengineering.eu2025-07-24T21:17:44Zurn:sha1:3183f22ccc77e5092775af6d5b5be680a3c9127d
This chip provides a globally unique EUI-48 MAC address. This address
will be printed on the device enclosure.
The IPv6 link-local address of the device can be directly calculated
from this MAC address. Thus a commissioning software can directly access
the device when the user types in this MAC address without any discovery
protocol.
pcb: Use red LED for error indication2025-07-24T20:51:23Zxengineeringme@xengineering.eu2025-07-24T20:51:23Zurn:sha1:360bc81c7532b6677dfb01898bbd94eca6ab75d2
The idea of the red LED used to be to indicate power delivery to the
board independent of firmware.
While this is good to know it adds the constraint that even without
firmware the LED should light up. Furthermore it should stop lighting up
when the firmware takes over the blinking with different colors. This
was solved with a NOT gate.
This adds more parts to the assembly at the cost of rare space. To
reduce space consumption this feature is removed.
The effect is that the user cannot distinguish anymore if the board has
an issue with power supply or with not running firmware. This is
acceptable because the user cannot do anything about both issues.
Developers have the chance to e.g. connect the UART to validate if the
firmware is running.
pcb: Connect RMII, MDIO and PHY reset2025-07-24T12:45:32Zxengineeringme@xengineering.eu2025-07-23T12:00:31Zurn:sha1:5e15c86cd5197466653f510a7ccc4b76d67f69d1pcb: Move version detection to processor schematic2025-07-23T09:57:32Zxengineeringme@xengineering.eu2025-07-23T09:57:32Zurn:sha1:24d9a38a95a7cc51528efebcb5d81dd8ea67bef8pcb: processor: Add TODO for MAC EEPROM2025-05-28T18:45:18Zxengineeringme@xengineering.eu2025-05-28T16:58:56Zurn:sha1:d5d2f7db13aeb4283387de5d7e90ebe1966c6c98pcb: processor: Finish first schematic2025-05-25T18:08:39Zxengineeringme@xengineering.eu2025-05-24T20:00:19Zurn:sha1:161dd48aa8a14bb99a31e91480977e2961d27a72pcb: Invert button signals2025-05-24T12:04:13Zxengineeringme@xengineering.eu2025-05-24T12:04:13Zurn:sha1:5e48ef91e68fcddc591950ca56c930c50912454f
Making them active-low makes it easier to reset the MCU. For the wipe
functionality it does not make a role since it will simply be defined in
Devicetree.
pcb: Add voltage divider for PCB versioning2025-05-24T11:52:16Zxengineeringme@xengineering.eu2025-05-24T11:52:16Zurn:sha1:6db34475d1935f368bec60f530f88cd066924849
This voltage divider provides an analog voltage between GND and +3.3V to
indicate which hardware revision this board is.
Thus the same firmware image can be used on multiple PCB versions
compensating the hardware differences in software.
The resistor combinations are calculated by
`tools/resistory_selector.py`.
pcb: U1: Add STM32F427VIT6TR2025-05-24T10:01:55Zxengineeringme@xengineering.eu2025-04-11T16:14:59Zurn:sha1:36d369e46c84642ef4b2069619fb53a586b60055pcb: Update to KiCad 9.x2025-04-01T16:13:10Zxengineeringme@xengineering.eu2025-04-01T16:13:10Zurn:sha1:aa3a6384f14ee7d148b84523aa30723bc1020d39pcb: Add hierarchical labels and connections2025-02-18T18:44:49Zxengineeringme@xengineering.eu2025-02-18T18:44:49Zurn:sha1:968d182429594578654a983d8a5b605f8f152650pcb: Set title to `iot-contact`2025-02-18T18:09:20Zxengineeringme@xengineering.eu2025-02-18T18:09:20Zurn:sha1:ca4bdaf956ac6a100cc386e6119641c35807becapcb: Rename some signals2025-02-18T18:02:30Zxengineeringme@xengineering.eu2025-02-18T18:02:30Zurn:sha1:15e451d799cefd647fa14af569187645553877depcb: J2: Add UART pin header2025-02-15T20:49:14Zxengineeringme@xengineering.eu2025-02-15T20:49:04Zurn:sha1:b5a439b3268c055e0daddd86c34acf71dd62d9f0pcb: Fix connection errors reported by ERC2025-02-15T20:26:10Zxengineeringme@xengineering.eu2025-02-15T20:26:10Zurn:sha1:d9fedc339118a630cbe7b382b5c18b4930a9c8a5pcb: SW1-SW2: Add switches for reboot and wipe2025-02-15T19:28:57Zxengineeringme@xengineering.eu2025-02-15T19:28:57Zurn:sha1:86f5b56b1b6749fdddfb7ce0e7a2499233c69d37pcb: D1-D3: Add LEDs for PWR, UPD and ACT2025-02-15T13:03:26Zxengineeringme@xengineering.eu2025-02-15T12:50:09Zurn:sha1:b61465930b36603dda2e50ebf78f68386da9c30apcb: J1: Add JTAG connector2025-02-15T13:03:18Zxengineeringme@xengineering.eu2025-02-15T12:26:08Zurn:sha1:eab2bac5267657142a7ab78ebbf458cccc09ee1apcb: Add sub-schematics2025-02-14T12:41:27Zxengineeringme@xengineering.eu2025-02-03T20:48:04Zurn:sha1:de8bc23e81c136b2153fe93d87e5a5ba9e518878