# Interstate75W RP2350, BOOT pinout

**URL:** <https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030>\
**Category:** Support\
**Created:** [August 4, 2026, 11:11am UTC](https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030 "2026-08-04T11:11:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mouze06](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@mouze06](https://forums.pimoroni.com/u/mouze06)\
**Post date:** [August 4, 2026, 11:11am UTC](https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030/1 "2026-08-04T11:11:22Z")

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An external pulldown reset switch, connected to the RST solderpad, will reset the board, just like pressing the RST button. But an external pulldown bootselect switch, connected to the BOOT solderpad, has no function ? What do I miss ?

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**Author:** ![alphanumeric](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/alphanumeric/32/2729_2.png) [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)\
**Post date:** [August 4, 2026, 11:26am UTC](https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030/2 "2026-08-04T11:26:14Z")

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The schematic is here if that helps?

> **[Pimoroni\_Interstate\_75\_RP2350\_Schematic.pdf](https://cdn.shopify.com/s/files/1/0174/1800/files/Pimoroni_Interstate_75_RP2350_Schematic.pdf?v=1734542569)**
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> 121.20 KB

So, the **onboard** Boot button works?  
But your added Boot button doesn’t?  
Is your switch a momentary switch?

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<div class="post-metadata">

**Author:** ![mouze06](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@mouze06](https://forums.pimoroni.com/u/mouze06)\
**Post date:** [August 4, 2026, 12:06pm UTC](https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030/3 "2026-08-04T12:06:07Z")

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Thanks.

Onboard BOOT button works, added does not. Momentary, but held down during reset.

The schematics show 2\* 4k7 resistors in the USER\_SW circuit. Pulling down external will result in 1.65V at R4 instead of 0V with the SW\_BOOT switch. Which seems insufficient to be detected as low.

Perhaps the solderpad should have been labeled as SW\_C, ie. the third user switch.

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<div class="post-metadata">

**Author:** ![mouze06](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@mouze06](https://forums.pimoroni.com/u/mouze06)\
**Post date:** [August 4, 2026, 5:23pm UTC](https://forums.pimoroni.com/t/interstate75w-rp2350-boot-pinout/29030/4 "2026-08-04T17:23:49Z")

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A workaround for me is to set GPIO 22 as FUNC\_SIO, input and pulled up. Then, when the switch is detected, call reset\_usb\_boot(0,0) from pico/bootrom.h. The board then resets and enters the USB programming mode.