# Unwanted connection between STM32 pins **URL:** \ **Category:** STM32\ **Tags:** plecs-coder, stm32\ **Created:** [January 8, 2025, 1:27pm UTC](https://forum.plexim.com/t/unwanted-connection-between-stm32-pins/1661 "2025-01-08T13:27:04Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![HMgeorg](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/hmgeorg/32/2379_2.png) [@HMgeorg](https://forum.plexim.com/u/HMgeorg)\ **Post date:** [January 8, 2025, 1:27pm UTC](https://forum.plexim.com/t/unwanted-connection-between-stm32-pins/1661/1 "2025-01-08T13:27:05Z")
Hello everyone, I use the PLECS Coder with the STM32 G474 Nucleo board and am basically very happy with it. However, I have encountered a problem with my current project. I am using the PB6 as a digital input (pull-up) and the PA9 as an analog input. However, a pull-down (5.1 kOhm) is activated on the PB6 as soon as the ADC measures a voltage above 0.6 V on the PA9. This is due to the use of these pins for USB Type-C / USB Power Delivery. The pull-down effect can be deactivated if the bit UCPD1\_DBDIS=1 is set in the PWR\_CR3 register. This is also described in the ST forum ([Solved: STM32G441 GPIO PB4 and PB6 pullup not working - STMicroelectronics Community](https://community.st.com/t5/stm32-mcus-products/stm32g441-gpio-pb4-and-pb6-pullup-not-working/td-p/588489)) . It would be user friendly if the PLECS coder sets this bit directly when the PB6 is used as digital input. Best regards, Georg ---
**Author:** ![Bryan\_Lieblick](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/bryan_lieblick/32/10_2.png) [@Bryan\_Lieblick](https://forum.plexim.com/u/Bryan_Lieblick)\ **Post date:** [January 13, 2025, 6:59pm UTC](https://forum.plexim.com/t/unwanted-connection-between-stm32-pins/1661/2 "2025-01-13T18:59:07Z")
Hello Georg, There is a solution to configure the STM32 peripherals directly through the Low Level (LL) and Hardware Abstract Layer (HAL) drivers. I’ll send you the fix via a direct message. Regards, Bryan