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Elecrow-RD / CrowPi2

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Schematics for Sensor switch and power supply #26

Open rabagliati opened 3 years ago

rabagliati commented 3 years ago

I am enjoying my CrowPi2 - and I am glad that libraries for access to all the sensors are available.

I am using my Crowpi2 to interface to other hardware, at the same time as driving the LED and LCD displays - it makes an excellent controller.

Please - can I echo Pearl-852 in asking for release of the schematics around the Sensor switch, and the power supply switching between Barrel jack and USB power. The Crowpi2 is a Makers ideal platform, and in that spirit can I make a plea to release those schematics.

Pearl-852 commented 3 years ago

I would love to see the schematics of the USB power port circuit, as it is not delivering enough voltage to the Raspberry Pi causing the Pi to display the "Low Voltage Warning" message. (Issue #18)

rabagliati commented 3 years ago

This is another design, faced with the same problems around packaging as the CrowPi2 designers.

YouTube series - https://www.youtube.com/channel/UCnmjLVLoxTEK_aprpLuw2LQ

There are pictures at https://imgur.com/a/BkcIFII

also he puts in a power booster. For people here, I think the best is to run it off the barrel jack.

CrowPi2 designers put most of the power components in the unit - so, use them - from 12V.

For me it would be more convenient from 18V - my power drill battery - or even 19V - the inevitable old laptop charger doing nothing. It is for this reason I would like the schematics.

berista commented 3 years ago

Hello everyone I want to run my Crowpi2 on a brand new Powerbank and was running into some strange observations. While on the barrel jack, i measured 5.11V, on the Powerbank 4.8ish Volts. I tested with a different powerbank with fixed 5V output I disconnected the 2 phase connector cable from the Rpi and plugged the powerbank back in. Obviously The RPi is also powered via GPIO Header (also giving low power lightning bolt) but i have no measurement atm.

Tested on Rpi 4, 4GB, Rev1.4

It is mentioned on the official forum, that undervoltage warning is by "design" (Downward compatibility for Rpi 3 with micro USB vs. USB-C on RPi4). It somehow loses 0.3 Volts in the internal wiring. I hope this helps

rabagliati commented 3 years ago

This ticket has been open for 9 months now.

I wish to use SPI from my CrowPi2, to talk to some custom hardware, and also to write to the LED displays on the CrowPi2.

SPI1 SCLK seems to be used for the stepper motor.

SPI0 seems usable - even though RFID is using CE0 and DHT11 uses CE1, the driver supports using other pins for those functions.

Importantly, SCLK, MOSI and MISO seem to be free.

Please give us the schematics around the GPIO pins, and the Sensor Switch.