See the latest version in the documentation wiki.
Bus: SPI (serial peripheral interface).
Connections: four pins (MOSI/MISO/CLOCK/CS) and ground.
Output type: 3.3volt normal, or open collector (pull-up resistors required).
Pull-up resistors: required for open drain output mode (2K – 10K).
Maximum voltage: 5.5volts (5volt safe).
| Syntax | Description |
| 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 or 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. |
| 0h/0x | Write this HEX value. Format is 0h01 or 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, 0h, 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 0haF}. |
| & | Delay 1uS. (&:1…255 for multiple delays) |
| (#) | Run macro, (0) for macro list |
| Macro | Description |
| 0 | Macro menu |
| 1 | SPI bus sniffer with configurable CS filter. |
Configuration options
Speed - 30kHz, 125kHz, 250kHz, 1MHz.
Clock polarity - idle low, idle high.
Output clock edge - idle to active, active to idle.
Input sample phase – middle, end.
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.
SPI Bus sniffer
The SPI sniffer is implemented in hardware and should work up to 10MHz. It follows the configuration settings you entered for SPI mode.
- [/] – CS enable/disable
- 0xXX – MOSI read
- (0xXX) – MISO read
SPI CS pin transitions are represented by the normal Bus Pirate syntax. The byte sniffed on the MISO pin is displayed inside ().
SPI>(1)
Sniff when:
1. CS low
2. CS high
3. All traffic
(1) >
SPI bus sniffer, any key exists
[0x30(0x00)0xff(0x12)0xff(0x50)][0x40(0x00)]
The SPI sniffer can read all traffic, or filter by the state of the CS pin. The byte sniffed on the MOSI pin is displayed as a HEX formatted value, the byte sniffed on the MISO pin is inside the ().
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I’m using the bus-pirate (v2go with v3.1FW) to sniff a SPI port, I sometimes get an output in the terminal which isn’t correctly HEX formatted, for example: 0×0x01F.
Any ideas of what is causing this? -
Oh nevermind.. I’m sniffing continuous 8Mhz SPI data, so the little BusPirate isn’t happy as it is over running the buffer. I really should be using a logic analyser instead.
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I think there is a bug in CS sniffing. It’s set like an output and goes low after entering sniffing mode, then goes up after exiting sniffing mode.
Anyone got the same behaviour? -
We need BusPirate for SPI sniffing only (no outputs on bus, not exercising devices), but SPI mode interferes whenever connected to SPI bus!
When SPI mode is not sniffing (at SPI prompt, esp. after sniffing interrupted by keystroke), data line (at least MOSI) appears to be driven or held by BusPirate, instead of released or left open (Hi-Z). The effect is system under test ceases to operate when BusPirate at SPI> prompt is attached. Workaround is to start sniffing “macro” (1) before attaching to SPI bus.
What is needed (should be default, IMHO) is for all SPI pins to input-only except when issuing output onto the bus; or else a setting option for this.
What is SPI (1) “macro” — can it be edited, can its commands be used?
[Also, any option for BusPirate to power up back into last-used configuration and state, after power-down? We would like to "set and forget" instead of having to record/remember all configuration choice each time we re-power the device.] -
I’ll be more than happy to try things out and provide feedback.
I’d also like to try some tweaks and builds of our own; if I can join the fray without disrupting it, is the build setup written up somewhere? -
I am trying to use BP to do some SPI sniffing as well… Not much success, even the instructions look straight forward….
In my case, I just wanted to make sure I understand the process correctly. I am tapping into a circuit I build, with SPI running @ 5MHz. Beside from the effects (hold up the SPI bus before going into sniffing mode) I can’t seem to getting anything (maybe a [ or ] for one time and that’s it)
And for the whole time I know the SPI bus is working because the other (16F88 -> MAX7219) end continuously receiving data…
On a side note…. a tutorial (or even new feature – CAN Bus interface. Hint: OBD II) to use it with MCP2515 would be awesome!
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