Tool/software:
I found a little problem when reading the user EEPROM.
Unfortunately, I don't have an explanation for it.
In principle, the transmission of data and temperature works without any problems. So we can discard hardware problems.
Now to the problem:
There is exactly one TMP1826 on the bus. (No other devices) The bus voltage is 3.3V; pull-up resistor is 1K; high pulse 7.5us; low pulse 60us.
1. I send a reset (500us) and receive a response.
2. I send the match ROM 0x55, family code, ROM code and CRC.
3. I send 0xF0 (READ EEPROM)
4. I send two address bytes 0x00 0x00
5. Waiting time 1.7ms; the bus is inactive (3.3V)
6. I read exactly 8 bytes from the EEPROM and get plausible data.
-- AND NOW --
7. I send a reset of 500us and get NO response.
This condition remains after further resets.
The error can be avoided if I read another byte as a dummy after the 8 bytes.
Further remarks:
If I have several devices on the bus, there is a response to the reset. But the next match ROM 0x55 is disturbed because the ‘error’ device is still sending data.
What information in the data sheet did I miss?
