ESP32-PaxCounter/src/i2c.cpp
2022-06-03 12:00:58 +02:00

114 lines
3.1 KiB
C++

// Basic config
#include "globals.h"
#include "i2c.h"
// Local logging tag
static const char TAG[] = __FILE__;
SemaphoreHandle_t I2Caccess;
void i2c_init(void) {
Wire.setPins(MY_DISPLAY_SDA, MY_DISPLAY_SCL);
Wire.begin();
}
void i2c_deinit(void) { Wire.end(); }
void i2c_scan(void) {
// parts of the code in this function were taken from:
//
// Copyright (c) 2019 BitBank Software, Inc.
// Written by Larry Bank
// email: bitbank@pobox.com
// Project started 25/02/2019
//
// 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 3 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/>.
BBI2C bbi2c;
ESP_LOGI(TAG, "Starting I2C bus scan...");
memset(&bbi2c, 0, sizeof(bbi2c));
bbi2c.bWire = 1;
bbi2c.iSDA = MY_DISPLAY_SDA;
bbi2c.iSCL = MY_DISPLAY_SCL;
I2CInit(&bbi2c, 100000L); // Scan at 100KHz low speed
delay(100); // allow devices to power up
uint8_t map[16];
uint8_t i;
int iDevice, iCount;
uint32_t iDevCapab;
char szName[15];
I2CScan(&bbi2c, map); // get bitmap of connected I2C devices
if (map[0] == 0xfe) // something is wrong with the I2C bus
{
ESP_LOGI(TAG, "I2C pins are not correct or the bus is being pulled low "
"by a bad device; unable to run scan");
} else {
iCount = 0;
for (i = 1; i < 128; i++) // skip address 0 (general call address) since
// more than 1 device can respond
{
if (map[i >> 3] & (1 << (i & 7))) // device found
{
iCount++;
iDevice = I2CDiscoverDevice(&bbi2c, i, &iDevCapab);
I2CGetDeviceName(iDevice, szName);
ESP_LOGI(TAG, "Device found at 0x%X, type = %s", i,
szName); // show the device name as a string
}
} // for i
ESP_LOGI(TAG, "%u I2C device(s) found", iCount);
}
}
// functions for i2c r/w access, mutexing is done by Wire.cpp
int i2c_readBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
uint8_t ret = 0;
Wire.beginTransmission(addr);
Wire.write(reg);
Wire.endTransmission(false);
uint8_t cnt = Wire.requestFrom(addr, (uint8_t)len, (uint8_t)1);
if (!cnt)
ret = 0xFF;
uint16_t index = 0;
while (Wire.available()) {
if (index > len) {
ret = 0xFF;
goto finish;
}
data[index++] = Wire.read();
}
finish:
return ret ? ret : 0xFF;
}
int i2c_writeBytes(uint8_t addr, uint8_t reg, uint8_t *data, uint8_t len) {
uint8_t ret = 0;
Wire.beginTransmission(addr);
Wire.write(reg);
for (uint16_t i = 0; i < len; i++) {
Wire.write(data[i]);
}
ret = Wire.endTransmission();
return ret ? ret : 0xFF;
}