pcb v1.7 upgrade update

pull/3/head
davor 7 years ago
parent 5ae86e21bc
commit d2b273fd79

@ -25,18 +25,19 @@ Mount:
U10 FLASH: IS25LP032D-JNLE-TR SOIC-8 150mil
U9 WIFI: ESP32, but not all pins! read below:
Don't connect ESP32 pins leading to SD card
those are 6 central pins from on the top 10-pin row of
ESP32 chip (only 2 pins on left side and 2 pins on right
side shuould be connected). Either cut the traces or carefully
solder without touching SD card pins.
Don't connect ESP32 pins leading to SD card,
in the top 10-pin row, connect only 2 pins on left side and 2 pins on right
and leave 6 central pins unconnected. GND and VCC
can be connected, but no other SD signal pins.
Either cut the traces or carefully solder without
touching those pads.
# What is fixed
Shutdown:
on assembled PCB v1.7, D11=1N4148 and R4=15k will
keep waking the board up after shutdown signal because FT231x internal
PCB v1.7 assembled comes with D11=1N4148 and R4=15k, those will
keep waking up the board after shutdown signal because FT231x internal
regulator will provide enough voltage (cca 2.5V will appear at 3.3V line)
and that is enough to wake up the board because voltage
on ENABLE pin at switching regulators will be above its turn on
@ -50,23 +51,22 @@ self-hold switching regulator during normal operation and at controlled
shutdown signal, it will drop below turn-off threshold, allowing reliable
shutdown.
Software shutdown is not routed to BGA pads so alternative patch is
to connect any GPIO (we recommend "25-") to SHUTDOWN.
Software shutdown is not routed to BGA pads. It is possible to connect
any GPIO (we recommend "25-") to SHUTDOWN.
I2C:
Too low pull up resistors (470 ohm) are at 5V side of the level converter PCA9306
and some monitors won't tolerate that. Data traffic at i2c will be
errorneously received by some monitors and some serious problem may arrise
if monitor interprets some data garbage as random write command, overwriting
its internal settings, then monitor will become useless.
Correct pull up resistors are 4.7k and they work properly.
and some monitors will receive niose with that. If data traffic at i2c is
not received 100% error-free, some monitors will get into serious problems.
When monitor interprets some data garbage as random write command and
overwrites its internal settings, such monitor might become premanently
useless. Correct pull up resistors are 4.7k and they should work properly.
WIFI:
On PCB v1.7, SD card is connected to ESP32 pins that are widely advertised
as SD card pins, but the problem is those pins are shared with internal flash
chip and ESP32 won't boot from its SPI FLASH if anything is connected there.
SD card should be connected on some other pins, probably HSPI. It has not
yet been verified will that work.
On PCB v1.7 SD card is connected to those ESP32 pins which are widely advertised
as SD card pins, but those pins are shared with internal SPI FLASH of ESP32
chip it won't boot if anything is connected there.
SD card should be connected on some other pins, probably HSPI.
It has not yet been verified will it work, so no patch recommendation yet.

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