diff options
Diffstat (limited to 'stmhal/spi.c')
| -rw-r--r-- | stmhal/spi.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/stmhal/spi.c b/stmhal/spi.c index 352c594c9..99bc08c3b 100644 --- a/stmhal/spi.c +++ b/stmhal/spi.c @@ -14,6 +14,25 @@ #include "bufhelper.h" #include "spi.h" +// Usage model: +// +// See usage model of I2C in i2c.c. SPI is very similar. Main difference is +// parameters to init the SPI bus: +// +// from pyb import SPI +// spi = SPI(1, SPI.MASTER, baudrate=600000, polarity=1, phase=1, crc=0x7) +// +// Only required parameter is mode, SPI.MASTER or SPI.SLAVE. Polarity can be +// 0 or 1, and is the level the idle clock line sits at. Phase can be 1 or 2 +// for number of edges. Crc can be None for no CRC, or a polynomial specifier. +// +// Additional method for SPI: +// +// data = spi.send_recv(b'1234') # send 4 bytes and receive 4 bytes +// buf = bytearray(4) +// spi.send_recv(b'1234', buf) # send 4 bytes and receive 4 into buf +// spi.send_recv(buf, buf) # send/recv 4 bytes from/to buf + #if MICROPY_HW_ENABLE_SPI1 SPI_HandleTypeDef SPIHandle1 = {.Instance = NULL}; #endif @@ -384,6 +403,9 @@ STATIC mp_obj_t pyb_spi_send_recv(uint n_args, const mp_obj_t *args, mp_map_t *k } else { // recv argument given mp_get_buffer_raise(vals[1].u_obj, &bufinfo_recv, MP_BUFFER_WRITE); + if (bufinfo_recv.len != bufinfo_send.len) { + nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "recv must be same length as send")); + } o_ret = MP_OBJ_NULL; } } |