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https://github.com/forkachild/MCP23017-ESP8266-Miniature-Driver
A simple driver for ESP8266 enthusiasts out there to drive MCP23017 16-bit IO Expander
https://github.com/forkachild/MCP23017-ESP8266-Miniature-Driver
api driver embedded embedded-c esp esp-open-sdk esp8266 esp8266-arduino espressif expander i2c i2c-bus i2c-interface i2c-sensors mcp23017 mcp23017-esp8266 pin switch xtensa
Last synced: 2 months ago
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A simple driver for ESP8266 enthusiasts out there to drive MCP23017 16-bit IO Expander
- Host: GitHub
- URL: https://github.com/forkachild/MCP23017-ESP8266-Miniature-Driver
- Owner: forkachild
- Created: 2017-02-20T09:58:09.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2017-02-21T08:40:05.000Z (almost 8 years ago)
- Last Synced: 2024-08-02T20:45:35.366Z (5 months ago)
- Topics: api, driver, embedded, embedded-c, esp, esp-open-sdk, esp8266, esp8266-arduino, espressif, expander, i2c, i2c-bus, i2c-interface, i2c-sensors, mcp23017, mcp23017-esp8266, pin, switch, xtensa
- Language: C
- Size: 45.9 KB
- Stars: 12
- Watchers: 4
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
- awesome-mpython - MCP23017-ESP8266-Miniature-Driver - Driver for MCP23017 16-bit I/O Expander. (精选驱动库 / 功能类)
README
# MCP23017 ESP8266 Miniature Driver
This is a simple MCP23017 driver for ESP8266. MCP23017 is an I/O Expander, which means it provides 16 fully customizable Input/Output pins for any microcontroller supporting I2C protocol. ESP8266 is a powerful chip, except that it lacks the I2C hardware. This library is a fully functional controller for the same. Kudos to developing in C.
The work is heavily based on [this](https://github.com/eadf/esp8266_mcp23017) library. The I2C driver is a modified port of the `i2c_master` library from the `esp-open-sdk`.
Usage is pretty straightforward. No I2C library required. Easy to understand API.
## Schematic
## Customize SDA & SCL GPIO, Logging and addressing
```c
// user_config.h
// Choose GPIO
#define MCP_SDA_GPIO 14
#define MCP_SCL_GPIO 12
// Debugging mode
#define MCP_LOG_EN
// Custom MCP23017 address
#define MCP_A0 0
#define MCP_A1 0
#define MCP_A3 0
```
## Configuration uses a few function calls
```c
#include "mcp.h"
mcpInit();
// Set pin mode to input or output, individual bits can be ORed
mcpSetPinmode(MCP_PORTA, MCP_OUTPUT);
mcpSetPinmode(MCP_PORTB, 0x0E);
// Configure internal pullups (for input modes only), individual bits can be ORed
mcpSetPullups(MCP_PORTB, MCP_PULL_HIGH);
// Input polarity can be changed, and yet again individual bits can be ORed
mcpSetInputPolarity(MCP_PORTA, MCP_IPOL_INVERTED);
```
## Effortlessly control GPIO
```c
uint8 input;
mcpSetGpio(MCP_PORTA, 0xF0);
mcpGetGpio(MCP_PORTB, &input);
```
## Examples
### Blinky
We all know this one
```c
// user_main.c
#include "os_type.h"
#include "mcp.h"
#define LED_PIN (1 << 0)
os_timer_t timer;
bool toggle = false;
LOCAL void ICACHE_FLASH_ATTR timerPoll(void *arg) {
if(toggle) {
mcpSetGpio(MCP_PORTA, LED_PIN); // Switch on LED
toggle = false;
} else {
mcpSetGpio(MCP_PORTA, 0); // Switch off LED
toggle = true;
}
}
LOCAL void ICACHE_FLASH_ATTR initDoneCb() {
os_timer_disarm(&timer);
os_timer_setfn(&timer, (os_timer_func_t *) timerPoll);
os_timer_arm(&timer, 1000, true); // Create timer
}
void user_init() {
mcpInit(); // Init the library
mcpSetPinmode(MCP_PORTA, MCP_OUTPUT); // Set full Port A as output
system_init_done_cb(initDoneCb);
}
```
### Read switch to control an LED
The switch is push-to-close and connects PORTB pin 0 to ground.
```c
// user_main.c
#include "os_type.h"
#include "mcp.h"
#define LED_PIN (1 << 0)
#define SWITCH_PIN (1 << 0)
os_timer_t timer;
uint8 data;
LOCAL void ICACHE_FLASH_ATTR timerPoll(void *arg) {
mcpGetGpio(PORTB, &data); // Read Port B where switch is connected
if(data & SWITCH_PIN) { // Check whether switch is on
mcpSetGpio(MCP_PORTA, LED_PIN); // Switch on LED
} else {
mcpSetGpio(MCP_PORTA, 0); // Switch off LED
}
}
LOCAL void ICACHE_FLASH_ATTR initDoneCb() {
os_timer_disarm(&timer);
os_timer_setfn(&timer, (os_timer_func_t *) timerPoll);
os_timer_arm(&timer, 100, true); // Create timer to poll switch
}
void user_init() {
mcpInit(); // Init the library
mcpSetPinmode(MCP_PORTA, MCP_OUTPUT); // Set full Port A as output
mcpSetPinmode(MCP_PORTB, MCP_INPUT); // Set full Port B as input
mcpSetPullups(MCP_PORTB, MCP_PULL_HIGH); // Pullup Port B pins for switch to pull it down on press
mcpSetInputPolarity(MCP_PORTB, MCP_INVERTED); // Polrity has to be reversed since pullup has to mean 1
system_init_done_cb(initDoneCb);
}
```
### Enjoy