From 4d3ac5e66b98dd1766e44386970b8822a110e97b Mon Sep 17 00:00:00 2001 From: BjoernSch Date: Tue, 9 Aug 2016 13:19:40 +0200 Subject: [PATCH] Added (some) missing documentation The man page is still missing the new functions --- pigpio.h | 4 ++-- pigpio.py | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 61 insertions(+), 4 deletions(-) diff --git a/pigpio.h b/pigpio.h index b82932e..07d81d9 100644 --- a/pigpio.h +++ b/pigpio.h @@ -2703,13 +2703,13 @@ len specifies the amount of bytes to be transferred. CS: 0-31 (as used in a prior call to [*bbSPIOpen*]) inBuf: pointer to buffer to hold data to be sent outBuf: pointer to buffer to hold returned data -outLen: size of output buffer +len: size of data transfer . . Returns >= 0 if OK (the number of bytes read), otherwise PI_BAD_USER_GPIO, PI_NOT_SPI_GPIO or PI_BAD_POINTER. -The returned I2C data is stored in consecutive locations of outBuf. +The returned SPI data is stored in consecutive locations of outBuf. D*/ /*F*/ diff --git a/pigpio.py b/pigpio.py index 8175ba4..b1f382c 100644 --- a/pigpio.py +++ b/pigpio.py @@ -2959,7 +2959,51 @@ class pi(): def bb_spi_open(self, CS, MISO, MOSI, SCLK, baud=100000, spi_flags=1): """ -### + This function selects a set of GPIO for bit banging SPI at a + specified baud rate. + + Bit banging SPI allows the use of different GPIO for SPI than + for the hardware SPI ports. + + CS := 0-31 + MISO := 0-31 + MOSI := 0-31 + SCLK := 0-31 + baud := 50-250000 + spiFlags := see below + + spiFlags consists of the least significant 22 bits. + + ... + 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + b b b b b b R T n n n n W A u2 u1 u0 p2 p1 p0 m m + ... + + mm defines the SPI mode. + + ... + Mode POL PHA + 0 0 0 + 1 0 1 + 2 1 0 + 3 1 1 + ... + + p0 is 0 if CEx is active low (default) and 1 for active high. + + T is 1 if the least significant bit is transmitted on MOSI first, + the default (0) shifts the most significant bit out first. + + R is 1 if the least significant bit is received on MISO first, the + default (0) receives the most significant bit first. + + The other bits in flags should be set to zero. + + Returns 0 if OK, otherwise PI_BAD_USER_GPIO, PI_BAD_SPI_BAUD, or + PI_GPIO_IN_USE. + ... + pi.bb_spi_open(CS, MISO, MOSI, SCLK, baud=100000, spi_flags=1) + ... """ # I p1 CS # I p2 0 @@ -2994,7 +3038,20 @@ class pi(): def bb_spi_xfer(self, CS, data): """ -### + This function executes an bit banged SPI transfer. The data + to be sent is specified by the contents of data, received data + is returned as a bytestring. + + CS:= 0-31 (as used in a prior call to [*bbSPIOpen*]) + data:= data to be sent + + Returns >= 0 if OK (the number of bytes read), otherwise + PI_BAD_USER_GPIO, PI_NOT_SPI_GPIO or PI_BAD_POINTER. + + The received SPI data returned as ab bytearray + ... + pi.bb_spi_xfer(CS, data) + ... """ # I p1 SDA # I p2 0