search

kriswiner / Ladybug

9 stars 4 forks source link

32.768 oscillator necessary? #6

Closed flybrianfly closed 1 year ago

flybrianfly commented 1 year ago

Hey Kris,

Making a custom board after prototyping with the Ladybug. Wondering if you know offhand if the 32.768 oscillator is needed if I'm not using the RTC? Would the core software need to be updated?

Thanks much!

kriswiner commented 1 year ago

Definitely required if you want to use the Tlera Corp Arduino core...

On Sun, Feb 5, 2023 at 3:43 PM Brian Taylor @.***> wrote:

Hey Kris,

Making a custom board after prototyping with the Ladybug. Wondering if you know offhand if the 32.768 oscillator is needed if I'm not using the RTC? Would the core software need to be updated?

Thanks much!

— Reply to this email directly, view it on GitHub https://github.com/kriswiner/Ladybug/issues/6, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABTDLKTU2BN4LJGDNEFZ55DWWA3I5ANCNFSM6AAAAAAUSBR2Y4 . You are receiving this because you are subscribed to this thread.Message ID: @.***>

flybrianfly commented 1 year ago

Hi @kriswiner, can you provide part numbers or specs for the oscillator and caps? I designed a custom board after prototyping with a Ladybug, but the USB isn't coming up and I'm suspecting that it's an issue with the oscillator I used. Thanks!

kriswiner commented 1 year ago

Any 20 ppm 32.768 kHz crystal with 4 pF capacitance. I use 5.6 pF balancing caps.

Send me your schematic and I will take a look.

On Tue, Mar 14, 2023 at 8:04 AM Brian Taylor @.***> wrote:

Hi @kriswiner https://github.com/kriswiner, can you provide part numbers or specs for the oscillator and caps? I designed a custom board after prototyping with a Ladybug, but the USB isn't coming up and I'm suspecting that it's an issue with the oscillator I used. Thanks!

— Reply to this email directly, view it on GitHub https://github.com/kriswiner/Ladybug/issues/6#issuecomment-1468277716, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABTDLKXGVOAYVATXWF5ARVTW4CCITANCNFSM6AAAAAAUSBR2Y4 . You are receiving this because you were mentioned.Message ID: @.***>

flybrianfly commented 1 year ago

Thanks @kriswiner! Just sent you an email. I'm suspecting maybe an issue with the oscillator and caps, I used a 6 pF oscillator and 4.3 pF balancing caps.

kriswiner commented 1 year ago

Nope, must connect VBUS to PA15 for USB serial to work in this design.

On Tue, Mar 14, 2023 at 10:35 AM Brian Taylor @.***> wrote:

Thanks @kriswiner https://github.com/kriswiner! Just sent you an email. I'm suspecting maybe an issue with the oscillator and caps, I used a 6 pF oscillator and 4.3 pF balancing caps.

— Reply to this email directly, view it on GitHub https://github.com/kriswiner/Ladybug/issues/6#issuecomment-1468538537, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABTDLKSFOK5BDMEUXLFBAVDW4CT6VANCNFSM6AAAAAAUSBR2Y4 . You are receiving this because you were mentioned.Message ID: @.***>

flybrianfly commented 1 year ago

Thanks! I managed to bodge that connection and it's working as expected now.