Raw 3-wire

From DP

Jump to: navigation , search



  • Bus: general purpose 3-wire library with bitwise pin control.
  • Connections: four pins (MOSI/MISO/CLOCK/CS) and ground.
  • Output types: 3.3volt normal, or open drain/open collector (pull-up resistors required).
  • Pull-up resistors: required for open drain output mode (2K – 10K).
  • Maximum voltage: 5.5volts (5volt safe).
  • Last documentation update: v5.6.

The raw 3 wire library is like SPI, but includes bitwise pin control.

Configuration options

Speed - high (~50kHz) and low (~5kHz).

Output type - open drain/open collector (high=Hi-Z, low=ground) , normal (high=3.3volts, low=ground). Use open drain/open collector output types with pull-up resistors for multi-voltage interfacing.


A/a/@ Toggle auxiliary pin. Capital “A” sets AUX high, small “a” sets to ground. @ sets aux to input (high impedance mode) and reads the pin value.
D/d Measure voltage on the ADC pin (v1+ hardware only).
W/w Capital ‘W’ enables the on-board power supplies. Small ‘w’ disables them. (v1+ hardware only).
[ Chip select (CS) active (low).
{ CS active (low), show the SPI read byte after every write.
] or } CS disable (high).
r Read one byte by sending dummy byte (0xff). (r:1…255 for bulk reads)
0b Write this binary value. Format is 0b00000000 for a byte, but partial bytes are also fine: 0b1001.
0x Write this HEX value. Format is 0×01. Partial bytes are fine: 0xA. A-F can be lower-case or capital letters.
0-255 Write this decimal value. Any number not preceded by 0x or 0b is interpreted as a decimal value.
, Value delimiter. Use a coma or space to separate numbers. Any combination is fine, no delimiter is required between non-number values: {0xa6,0, 0 16 5 0b111 0xaF}.
& Delay 1uS. (&:1…255 for multiple delays)
(#) Run macro, (0) for macro list
^ Send one clock tick. (^:1…255 for multiple clock ticks)
/ or \ Toggle clock level high (/) and low (\). Includes clock delay (100uS).
- or _ Toggle data state high (-) and low (_). Includes data setup delay (20uS).
 ! Read one bit with clock.
. Read data pin state (no clock).


Bus Pirate Dir. Circuit Description
MOSI MOSI Master Out, Slave In
MISO MISO Master In, Slave Out
CS CS Chip Select
CLK CLK Clock signal
GND GND Signal Ground