To test a Bus Pirate is working, connect +5V with VPU and 3.3V with ADC and access the bus pirate (Using Tera Term for example) and use the command ~:
# Use commandHiZ>~DisconnectanydevicesConnect (Vpu to+5V) and (ADCto+3.3V)Spacetocontinue# Press spaceCtrlAUXOKMODELEDOKPULLUPHOKPULLUPLOKVREGOKADCandsupply5V(4.96) OKVPU(4.96) OK3.3V(3.26) OKADC(3.27) OKBushighMOSIOKCLKOKMISOOKCSOKBusHi-Z0MOSIOKCLKOKMISOOKCSOKBusHi-Z1MOSIOKCLKOKMISOOKCSOKMODEandVREGLEDsshouldbeon!Anykeytoexit#Press spaceFound0errors.
As you can see in the previous command line it said that it found 0 errors. This is very useful to know it's working after buying it or after flashing a firmware.
To connect with the bus pirate you can follow the docs:
In this case I'm going to connect to an EPROM: ATMEL901 24C256 PU27:
To talk with bus pirate I used Tera Term connected to the pirate bus COM port with a Setup --> Serial Port --> Speed of 115200.
In the following communication you can find how to prepare the bus pirate to talk I2C and how to write and read from the memory (Comments appear using "#", don't expect that part in the communication):
# Check communication with buspirateiBusPiratev3.5CommunityFirmwarev7.1-goo.gl/gCzQnW [HiZ 1-WIREUARTI2CSPI2WIRE3WIREKEYBLCDPICDIO]Bootloaderv4.5DEVID:0x0447REVID:0x3046 (24FJ64GA00 2B8)http://dangerousprototypes.com# Check voltagesI2C>vPinstates:1.(BR) 2.(RD) 3.(OR) 4.(YW) 5.(GN) 6.(BL) 7.(PU) 8.(GR) 9.(WT) 0.(Blk)GND3.3V5.0VADCVPUAUXSCLSDA--PPPIIIIIIIGND3.27V4.96V0.00V4.96VLHHLL#Notice how the VPU is in 5V becausethe EPROM needs 5V signals# Get mode optionsHiZ>m1.HiZ2.1-WIRE3.UART4.I2C5.SPI6.2WIRE7.3WIRE8.KEYB9.LCD10.PIC11.DIOx.exit(withoutchange)# Select I2C(1)>4I2Cmode:1.Software2.Hardware# Select Software mode(1)>1Setspeed:1.~5kHz2.~50kHz3.~100kHz4.~240kHz# Select communication spped(1)> 2Clutchdisengaged!!!Tofinishsetup,startupthepowersupplieswithcommand'W'Ready# Start communicationI2C>WPOWERSUPPLIESONClutchengaged!!!# Get macrosI2C>(0)0.Macromenu1.7bitaddresssearch2.I2Csniffer#Get addresses of slaves connectedI2C>(1)SearchingI2Caddressspace.Founddevicesat:0xA0(0x50W) 0xA1(0x50R)# Note that each slave will have a write address and a read address# 0xA0 ad 0xA1 in the previous case# Write "BBB" in address 0x69I2C>[0xA00x000x690x420x420x42]I2CSTARTBITWRITE:0xA0ACKWRITE:0x00ACKWRITE:0x69ACKWRITE:0x42ACKWRITE:0x42ACKWRITE:0x42ACKI2CSTOPBIT# Prepare to read from address 0x69I2C>[0xA00x000x69]I2CSTARTBITWRITE:0xA0ACKWRITE:0x00ACKWRITE:0x69ACKI2CSTOPBIT# Read 20B from address 0x69 configured beforeI2C>[0xA1r:20]I2CSTARTBITWRITE:0xA1ACKREAD:0x42ACK0x42ACK0x42ACK0x20ACK0x48ACK0x69ACK0x20ACK0x44ACK0x72ACK0x65ACK0x67ACK0x21ACK0x20ACK0x41ACK0x41ACK0x41ACK0x00ACK0xFFACK0xFFACK0xFFNACK
Sniffer
In this scenario we are going to sniff the I2C communication between the arduino and the previous EPROM, you just need to communicate both devices and then connect the bus pirate to the SCL, SDA and GND pins:
I2C>m1.HiZ2.1-WIRE3.UART4.I2C5.SPI6.2WIRE7.3WIRE8.KEYB9.LCD10.PIC11.DIOx.exit(withoutchange)(1)>4I2Cmode:1.Software2.Hardware(1)>1Setspeed:1.~5kHz2.~50kHz3.~100kHz4.~240kHz(1)>1Clutchdisengaged!!!Tofinishsetup,startupthepowersupplieswithcommand'W'Ready# EVEN IF YOU ARE GOING TO SNIFF YOU NEED TO POWER ON!I2C>WPOWERSUPPLIESONClutchengaged!!!# Start sniffing, you can see we sniffed a write commandI2C>(2)SnifferAnykeytoexit[0xA0+0x00+0x69+0x41+0x41+0x41+0x20+0x48+0x69+0x20+0x44+0x72+0x65+0x67+0x21+0x20+0x41+0x41+0x41+0x00+]