Protocol decoder:nes_gamepad
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 | |
| Name | NES gamepad |
|---|---|
| Description | NES gamepad button states. |
| Status | supported |
| License | GPLv2+ |
| Source code | decoders/nes_gamepad |
| Input | spi |
| Output | — |
| Probes | CLK, MOSI |
| Optional probes | — |
| Options | variant |
Please note: This page is a work in progress, more to come.
This decoder stacks on top of the spi PD and decodes the button states
of an NES gamepad. Currently only the standard controller is supported. This might be
extended by special controllers like the Nintendo Zapper light gun.
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.
Hardware
The NES gamepad consists of a single 4021 shift register:
4021 shift register pinout::
| PI-8 | 1- | O | -16 | VCC |
| Q6 | 2- | -15 | PI-7 | |
| Q8 | 3- | -14 | PI-6 | |
| PI-4 | 4- | -13 | PI-5 | |
| PI-3 | 5- | -12 | Q7 | |
| PI-2 | 6- | -11 | Serial In | |
| PI-1 | 7- | -10 | Clock | |
| GND | 8- | -9 | Parallel/Serial control |
Resources
- (S)NES controller pinout (pinoutguide.com)
- (S)NES controller pinout (wiki.nesdev.com)
- Video: SNES controller explained (For SNES but principle is the same for NES)
- Datasheet of 4021 shift register