diff options
Diffstat (limited to 'decoders/max7219')
| -rw-r--r-- | decoders/max7219/__init__.py | 26 | ||||
| -rw-r--r-- | decoders/max7219/pd.py | 109 |
2 files changed, 135 insertions, 0 deletions
diff --git a/decoders/max7219/__init__.py b/decoders/max7219/__init__.py new file mode 100644 index 0000000..249f09c --- /dev/null +++ b/decoders/max7219/__init__.py @@ -0,0 +1,26 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2015 Paul Evans <leonerd@leonerd.org.uk> +## +## This program is free software; you can redistribute it and/or modify +## it under the terms of the GNU General Public License as published by +## the Free Software Foundation; either version 2 of the License, or +## (at your option) any later version. +## +## This program is distributed in the hope that it will be useful, +## but WITHOUT ANY WARRANTY; without even the implied warranty of +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +## GNU General Public License for more details. +## +## You should have received a copy of the GNU General Public License +## along with this program; if not, write to the Free Software +## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +## + +''' +This decoder stacks on top of the 'spi' PD and decodes the Maxim MAX7219 and +MAX7221 LED matrix driver protocol. +''' + +from .pd import Decoder diff --git a/decoders/max7219/pd.py b/decoders/max7219/pd.py new file mode 100644 index 0000000..c05ff84 --- /dev/null +++ b/decoders/max7219/pd.py @@ -0,0 +1,109 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2015 Paul Evans <leonerd@leonerd.org.uk> +## +## This program is free software; you can redistribute it and/or modify +## it under the terms of the GNU General Public License as published by +## the Free Software Foundation; either version 2 of the License, or +## (at your option) any later version. +## +## This program is distributed in the hope that it will be useful, +## but WITHOUT ANY WARRANTY; without even the implied warranty of +## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +## GNU General Public License for more details. +## +## You should have received a copy of the GNU General Public License +## along with this program; if not, write to the Free Software +## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +## + +import re +import sigrokdecode as srd + +def _decode_intensity(val): + intensity = val & 0x0f + if intensity == 0: + return 'min' + elif intensity == 15: + return 'max' + else: + return intensity + +registers = { + 0x00: ['No-op', lambda _: ''], + 0x09: ['Decode', lambda v: '0b{:08b}'.format(v)], + 0x0A: ['Intensity', _decode_intensity], + 0x0B: ['Scan limit', lambda v: 1 + v], + 0x0C: ['Shutdown', lambda v: 'off' if v else 'on'], + 0x0F: ['Display test', lambda v: 'on' if v else 'off'] +} + +ann_reg, ann_digit, ann_warning = range(3) + +class Decoder(srd.Decoder): + api_version = 2 + id = 'max7219' + name = 'MAX7219' + longname = 'Maxim MAX7219/MAX7221' + desc = '8-digit LED display driver.' + license = 'gplv2+' + inputs = ['spi'] + outputs = ['max7219'] + annotations = ( + ('register', 'Registers written to the device'), + ('digit', 'Digits displayed on the device'), + ('warnings', 'Human-readable warnings'), + ) + annotation_rows = ( + ('commands', 'Commands', (ann_reg, ann_digit)), + ('warnings', 'Warnings', (ann_warning,)), + ) + + def start(self): + self.out_ann = self.register(srd.OUTPUT_ANN) + self.pos = 0 + self.cs_start = 0 + + def putreg(self, ss, es, reg, value): + self.put(ss, es, self.out_ann, [ann_reg, ['%s: %s' % (reg, value)]]) + + def putdigit(self, ss, es, digit, value): + self.put(ss, es, self.out_ann, [ann_digit, ['Digit %d: %02X' % (digit, value)]]) + + def putwarn(self, ss, es, message): + self.put(ss, es, self.out_ann, [ann_warning, [message]]) + + def decode(self, ss, es, data): + ptype, mosi, _ = data + + if ptype == 'DATA': + if not self.cs_asserted: + return + + if self.pos == 0: + self.addr = mosi + self.addr_start = ss + elif self.pos == 1: + if self.addr >= 1 and self.addr <= 8: + self.putdigit(self.addr_start, es, self.addr, mosi) + elif self.addr in registers: + name, decoder = registers[self.addr] + self.putreg(self.addr_start, es, name, decoder(mosi)) + else: + self.putwarn(self.addr_start, es, + 'Unknown register %02X' % (self.addr)) + + self.pos += 1 + elif ptype == 'CS-CHANGE': + self.cs_asserted = mosi + if self.cs_asserted: + self.pos = 0 + self.cs_start = ss + else: + if self.pos == 1: + # Don't warn if pos=0 so that CS# glitches don't appear + # as spurious warnings. + self.putwarn(self.cs_start, es, 'Short write') + elif self.pos > 2: + self.putwarn(self.cs_start, es, 'Overlong write') |