Suggestion
I noticed that in your excellent blog post explaining your project you explain how you use the 5V rail to power the I2C components and also explain why this is OK to do as long as you carefully vet the datasheets of your components. They must all be configured as open drain. or you will smoke.
I decided to use the 3.3V rail for most of them and 5V rail for only LCD which worked fine until I hit an edge case.. I discovered a brownout condition on startup where the out-rush current to the 3.3V powered i2c peripherals causes transient brownout and RPi fails to boot.
Perhaps just drop a line in your tutorial explaining that the 3.3V line is more limited through the LDO, and that you won't run into this issue on the higher amperage 5V rail.
kizniche
commented
2 years ago
Suggestion I noticed that in your excellent blog post explaining your project you explain how you use the 5V rail to power the I2C components and also explain why this is OK to do as long as you carefully vet the datasheets of your components. They must all be configured as open drain. or you will smoke.
I decided to use the 3.3V rail for most of them and 5V rail for only LCD which worked fine until I hit an edge case.. I discovered a brownout condition on startup where the out-rush current to the 3.3V powered i2c peripherals causes transient brownout and RPi fails to boot.
Perhaps just drop a line in your tutorial explaining that the 3.3V line is more limited through the LDO, and that you won't run into this issue on the higher amperage 5V rail.
Just my 2 cents.