nes_gamepad: implement and add decoder

1 files changed, 54 insertions, 0 deletions

diff --git a/decoders/nes_gamepad/__init__.py b/decoders/nes_gamepad/__init__.py
new file mode 100644
index 0000000..e754374
--- /dev/null
+++ b/decoders/nes_gamepad/__init__.py
@@ -0,0 +1,54 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2019 Stephan Thiele <stephan.thiele@mailbox.org>
+##
+## 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, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+This decoder stacks on top of the 'spi' PD and decodes the button states
+of an NES gamepad.
+
+The SPI decoder needs to be configured as follows:
+
+Clock polarity = 1
+Clock phase    = 0
+Bit order      = msb-first
+Word size      = 8
+
+Chip-select is not used and must not be assigned to any channel.
+
+Hardware setup is as follows:
+        ___
+   GND |o  \
+   CUP |o o| VCC
+ OUT 0 |o o| D3
+    D1 |o o| D4
+       -----
+NES Gamepad Connector
+
+VCC   - Power 5V
+GND   - Ground
+CUP   - Shift register clock (CLK)
+OUT 0 - Shift register latch (optional)
+D1    - Gamepad data (MOSI)
+D3    - Data (unused)
+D4    - Data (unused)
+
+Data pins D3 and D4 are not used by the standard gamepad but
+by special controllers like the Nintento Zapper light gun.
+'''
+
+from .pd import Decoder