A new open source hardware project every month
You are currently browsing the archive for the mods category.
Nuxx.net writes:
Today I finally got to poking around with the Hack A Day Bus Pirate v2.go … the LEDs on it are far, far, far brighter than they need to be. At my normally-lit desk in a normally-lit office, they are glaring. I’m going to consider replacing them next time I place an order from Mouser or Digi-Key.
Anyone else have this problem? We’d suggest a larger resistor, 2K+ on R3 and R30, and 600+ on R31 and R32.
The Bus Pirate v2go shipped with 10K ohm pull-up resistors (R20-23). We modded our Bus Pirate with a 2K pull-up resistor so we don’t need an external resistor to work with 1-Wire devices. Pull-up resistors larger than 2.2K ohms don’t provide enough current for parasitically powered 1-Wire parts. Since we only need the bigger resistor for the 1-Wire protocol, we only replaced the pull-up resistor on the MOSI pin (R23).
Read more about our mod after the break.
Tags: pull-up resistors
