Add a warning about duplicate USB pullup for STM32F4 boards

This is suboptimal hardware design, which might need some special care on the software side. This noticed in the Arduino_Core_STM32, see stm32duino/Arduino_Core_STM32#1029 For these boards, a schematic is available to confirm the resistor: - STM32F407VET6-STM32-F4VE-V2.0 - STM32F407ZGT6-VCC-GND-Large - STM32F407VET6-VCC-GND-Small These boards have not schematic, but there is a 1.5kΩ resistor clearly visible in the USB data path that is almost certainly a fixed pullup: - STM32F407VET6-Euse-M4-DEMO-Medium - STM32F407VGT6-SR-Board These boards have a pullup, but it is switched by a transistor. Since there are also internal pullups, a warning is still in order, but using slightly different wording: - STM32F401RCT6-STM32F-Core-Board - STM32F407ZGT6-STM32F-Core-Board All other F4 boards have no such resistor in the schematic or visible in the images. Other series might also have this problem, but were not checked.
matthijskooijman · Apr 29, 2020 · fce484e · fce484e
1 parent 1d05156
commit fce484e
Show file tree

Hide file tree

Showing 7 changed files with 14 additions and 7 deletions.
diff --git a/_data/boards/STM32F401RCT6-STM32F-Core-Board.json b/_data/boards/STM32F401RCT6-STM32F-Core-Board.json
@@ -38,7 +38,8 @@
         "mounting": "None"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional switchable pull-up resistor on D+ (R11, controlled by PD2), which is disabled by default. This resistor is not needed and violates the USB specification when used at the same time as the internal pull-up resistors. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407VET6-Euse-M4-DEMO-Medium.json b/_data/boards/STM32F407VET6-Euse-M4-DEMO-Medium.json
@@ -41,7 +41,8 @@
         "mounting": "4x mounting hole (M2)"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional pull-up resistor on D+. This resistor is not needed and violates the USB specification when the internal pull-up resistors are also used. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407VET6-STM32-F4VE-V2.0.json b/_data/boards/STM32F407VET6-STM32-F4VE-V2.0.json
@@ -38,7 +38,8 @@
         "mounting": "4x mounting hole (M3)"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional pull-up resistor on D+ (R21). This resistor is not needed and violates the USB specification when the internal pull-up resistors are also used. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407VET6-VCC-GND-Small.json b/_data/boards/STM32F407VET6-VCC-GND-Small.json
@@ -38,7 +38,8 @@
         "mounting": "None"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional pull-up resistor on D+ (R21). This resistors is not needed and violates the USB specification when the internal pull-up resistors are also used. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407VGT6-SR-Board.json b/_data/boards/STM32F407VGT6-SR-Board.json
@@ -35,7 +35,8 @@
         "mounting": "None"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional pull-up resistor on D+ (R8). This resistor is not needed and violates the USB specification when the internal pull-up resistors are also used. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407ZGT6-STM32F-Core-Board.json b/_data/boards/STM32F407ZGT6-STM32F-Core-Board.json
@@ -38,7 +38,8 @@
         "mounting": "None"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional switchable pull-up resistor on D+ (R14, controlled by PA8), which is disabled by default. This resistor is not needed and violates the USB specification when used at the same time as the internal pull-up resistors. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {

diff --git a/_data/boards/STM32F407ZGT6-VCC-GND-Large.json b/_data/boards/STM32F407ZGT6-VCC-GND-Large.json
@@ -38,7 +38,8 @@
         "mounting": "None"
     },
     "remarks": [
-        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." }
+        { "type": "warning", "content": "The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time." },
+        { "type": "warning", "content": "The microcontroller on this board features internal pull-up resistors for the USB data lines. However, this board has an additional pull-up resistor on D+ (R8). This resistor is not needed and violates the USB specification when the internal pull-up resistors are also used. This may cause errors while using USB on this board." }
     ],
     "resources": [
         {