Python client for GEX
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gex-client-py/units/SPI.py

52 lines
1.4 KiB

import gex
class SPI(gex.Unit):
"""
SPI master direct access
"""
def _type(self):
return 'SPI'
def query(self, slave:int, tbytes, rlen:int, rskip:int=-1, confirm=True):
"""
Query a slave.
If rskip is -1 (default), the tbytes length will be used.
Set it to 0 to skip nothing.
slave is 0-based index
"""
if rskip == -1:
rskip = len(tbytes)
pb = gex.PayloadBuilder()
pb.u8(slave)
pb.u16(rskip)
pb.u16(rlen)
pb.blob(tbytes)
# SPI does not respond if rlen is 0, but can be enforced using 'confirm'
if rlen > 0:
resp = self._query(0x00, pb.close())
return resp.data
else:
# write only
self._send(0x00, pb.close(), confirm=confirm)
return []
def write(self, slave:int, tbytes, confirm=True):
"""
Write with no response received
"""
self.query(slave, tbytes, rlen=0, rskip=0, confirm=confirm)
def multicast(self, slaves, tbytes, confirm=True):
"""
Write with multiple slaves at once.
Slaves is a right-aligned bitmap (eg. pins 0,2,3 would be 0b1101), or a list of active positions
"""
pb = gex.PayloadBuilder()
pb.u16(self.pins2int(slaves))
pb.blob(tbytes)
self._send(0x01, pb.close(), confirm=confirm)