https://github.com/pilotak/ds248x
A OneWire library using the DS2482 or DS2484 (1-Wire Master) for mbed.
https://github.com/pilotak/ds248x
1-wire ds18b20 ds18s20 ds2482-100 ds2482-800 ds2484 mbed mbed-os onewire
Last synced: 3 months ago
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A OneWire library using the DS2482 or DS2484 (1-Wire Master) for mbed.
- Host: GitHub
- URL: https://github.com/pilotak/ds248x
- Owner: pilotak
- License: mit
- Created: 2018-11-21T14:03:00.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2023-08-07T16:03:14.000Z (over 1 year ago)
- Last Synced: 2025-01-12T13:52:40.021Z (3 months ago)
- Topics: 1-wire, ds18b20, ds18s20, ds2482-100, ds2482-800, ds2484, mbed, mbed-os, onewire
- Language: C++
- Homepage:
- Size: 98.6 KB
- Stars: 4
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# 1-Wire library
[](https://os.mbed.com/)
[](https://github.com/pilotak/DS248X/actions/workflows/build.yml)
Supports following ICs:
- DS2484 *(single channel)*
- DS2482-100 *(single channel)*
- DS2482-800 *(8-channel)*
## Basic example
```cpp
#include "mbed.h"
#include "DS248X.h"
DS248X oneWire(I2C_SDA, I2C_SCL);
int main() {
if (!oneWire.init()) {
debug("Init failed\n");
return 0;
}
debug("At least one device on the bus: %u\n", oneWire.reset());
return 0;
}
```
## Example searching the bus
```cpp
#include "DS248X.h"
#include "mbed.h"
DS248X oneWire(I2C_SDA, I2C_SCL);
bool oneWireInit() {
if (!oneWire.init()) {
debug("Init failed\n");
return false;
}
if (!oneWire.setConfig(DS248X::ActivePullUp)) {
debug("Config failed\n");
return false;
}
return true;
}
void oneWireCb(char error) {
if (error & DS248X_CB_RESET_CONDITION) {
debug("1-Wire reset\n");
} else if (error & DS248X_CB_SHORT_CONDITION) {
debug("1-Wire short\n");
} else if (error & DS248X_CB_DEVICE_RESET_NEEDED) {
debug("Device reset needed\n");
oneWire.deviceReset();
oneWireInit();
}
}
int main() {
char rom[8];
uint8_t device_count = 0;
oneWire.attach(oneWireCb);
if (!oneWireInit()) {
return 0;
}
while (1) {
while (oneWire.search(rom)) {
device_count++;
debug("Found device: ");
for (size_t i = 0; i < sizeof(rom); i++) {
debug("%02X", rom[i]);
}
debug("\n");
}
oneWire.resetSearch();
debug("Total devices on the bus: %u\n\n", device_count);
device_count = 0;
ThisThread::sleep_for(5s);
}
}
```
## Example reading DS18B20 and passing I2C object
```cpp
#include "DS248X.h"
#include "mbed.h"
I2C i2c(I2C_SDA, I2C_SCL);
DS248X oneWire;
int main() {
char rom[8];
char data[9];
if (!oneWire.init(&i2c)) {
debug("Init failed\n");
return 0;
}
if (!oneWire.setConfig(DS248X::ActivePullUp)) {
debug("Config failed\n");
return 0;
}
while (1) {
if (!oneWire.search(rom)) {
debug("No devices on the bus\n");
ThisThread::sleep_for(1s);
continue;
}
oneWire.resetSearch();
if (rom[0] != 0x10 && rom[0] != 0x28) { // DS18S20 or DS18B20
debug("Not a temperature sensor\n");
continue;
}
debug("Temperature sensor found\n");
while (1) {
if (!oneWire.reset()) {
debug("Sensor is no longer on the bus\n");
break;
}
oneWire.select(rom);
// start conversion
data[0] = 0x44;
oneWire.writeBytes(data, 1, true); // use SPU if in parasitic mode
// wait for conversion
ThisThread::sleep_for(750ms); // default conversion (12bit) time is 750ms
oneWire.reset();
oneWire.select(rom);
// Read Scratchpad
data[0] = 0xBE;
oneWire.writeBytes(data, 1, true); // use SPU if in parasitic mode
oneWire.readBytes(data, 9, true); // use SPU if in parasitic mode
if (!oneWire.crc8(data, 9)) {
debug("Invalid CRC\n");
continue;
}
int16_t raw = (data[1] << 8) | data[0];
for (auto i = 0; i < 9; i++) {
printf("%02X ", data[i]);
}
printf("\n");
switch (rom[0]) {
case 0x10: { // DS18S20
raw = raw << 3;
if (data[7] == 0x10) {
raw = (raw & 0xFFF0) + 12 - data[6];
}
} break;
case 0x28: { // DS18B20
char cfg = (data[4] & 0x60); // default is 12 bit resolution
// 750ms conversion time
if (cfg == 0x00) { // 9 bit resolution, 93.75 ms
raw &= ~7;
} else if (cfg == 0x20) { // 10 bit res, 187.5 ms
raw &= ~3;
} else if (cfg == 0x40) { // 11 bit res, 375 ms
raw &= ~1;
}
}
default:
break;
}
printf("Temperature: %i *mC\n", ((int32_t)raw * 100) >> 4);
}
}
}
```