I'm using the OneWire library to try and read temperatures from a MAX31888 sensor using this Arduino program:
#include <SoftwareSerial.h>
#include <OneWire.h>
#define RX PB4
#define TX PB3
#define OW PB0
SoftwareSerial serial(RX, TX);
OneWire ds(OW);
void setup() {
serial.begin(19200);
delay(1000);
serial.println("TX_INIT");
}
void loop() {
byte addr[8];
if (!ds.search(addr)) {
serial.println("No more addresses.");
serial.println();
ds.reset_search();
delay(250);
return;
}
serial.print("ROM =");
for (byte i = 0; i < 8; i++) {
serial.write(' ');
serial.print(addr[i], HEX);
}
delay(5E3);
}
When I test this on an Arduino Nano, with hardware serial instead of software, I get the output I expect:
ROM = 54 36 25 5 0 0 0 3C
No more addresses.
But when I compile and burn the same program to an Attiny85, using the internal 8 MHz clock bootloader, all I get is:
No more addresses.
What could be the issue here? I've read DS18B20 sensors just fine with the 8 MHz internal clock bootloader before.
Software & library versions used:
- Arduino IDE ver. 2.2.1
- Arduino AVR Boards core for Nano, ver. 1.8.6
- ATTiny core ver. 1.0.2
- Onewire library ver. 2.3.7
Wiring diagram for ATTiny setup:
Diagram legend:
- U1: USB
- U2: ATTiny85
- U3: MCP2221
- J1: OneWire header
Please note that the VUSB pin of the MCP2221 outputs a regulated 3.3V.
