[BUG] spi_xfer Currently Fails #19
Description
Hi @Alexander-Barth and co,
Just wanted to report that while #18 did work to open a SPI interface, it now appears I am unable to write with SPI. Here's code in Python (using your tip about checking out the Python library):
import pigpio
pi = pigpio.pi()
SPI_CHANNEL = 0 # SPI channel (0 or 1)
SPI_SPEED = 1000000 # SPI speed in Hz (1 MHz)
SPI_FLAGS = 0 # SPI flags (0 for default)
handle = pi.spi_open(SPI_CHANNEL, SPI_SPEED, SPI_FLAGS)
data_to_send = [0x01, 0x02, 0x03, 0x04] # Example data
count, data_received = pi.spi_xfer(handle, data_to_send)And the output
>>> handle
0 # Or 1 -- this is correct to the Julia version
>>> count
4
>>> data_received
bytearray(b'\x00\x00\x00\x00')Here's the same version in Julia:
julia> using PiGPIO
julia> p = Pi();
[ Info: Successfully connected!
julia> h = PiGPIO.spi_open(p, 1, 100000, 0)
0
julia> data_to_send = [0x01, 0x02, 0x03, 0x04]
4-element Vector{UInt8}:
0x01
0x02
0x03
0x04
julia> count, data = PiGPIO.spi_xfer(p, h, data_to_send)
ERROR: UndefVarError: `u2i` not defined
Stacktrace:
[1] spi_xfer(self::Pi, handle::Int32, data::Vector{UInt8})
@ PiGPIO ~/.julia/packages/PiGPIO/UOeJH/src/spiSerial.jl:199
[2] top-level scope
@ REPL[5]:1I then tried to patch it with the following fix:
julia> function spi_xfer(self::Pi, handle, data)
# I p1 handle
# I p2 0
# I p3 len
## extension ##
# s len data bytes
# Don't raise exception. Must release lock.
bytes = signed(PiGPIO._pigpio_command_ext(
self.sl, PiGPIO._PI_CMD_SPIX, handle, 0, length(data), data, false))
if bytes > 0
data = PiGPIO.rxbuf(bytes)
else
data = ""
end
unlock(self.sl.l)
return bytes, data
end
spi_xfer (generic function with 1 method)
julia> (count, data) = spi_xfer(p, h, data_to_send)
(0, "")But that doesn't return what the Python version did. Any thoughts about how to fix this @Alexander-Barth or @aviks? I can examine the Python version a bit more, but was curious what your thought is here first.
Cheers!
~ tcp 🌳