| ??? 02/01/10 15:02 Read: times |
#172838 - Pullup resistor size... Responding to: ???'s previous message |
There are often times that a pull-up resistor of 10K on an I2C bus is too large of value. You should check the SCL and SDA signalling on an oscilloscope to make sure that your protocol is not being upset by too show of risetime on the bus lines.
At the same time that you have the scope connected up you should attempt to verify the serial transmission to ensure that every part of the protocol is correct and that the timing is valid. Do also check that the RTC chip is sending an ACK in the 9th SCL time slot of the transmission sequence. Michael Karas |
| Topic | Author | Date |
| problem with ds1307 andi2c | 01/01/70 00:00 | |
| Did you provide a resistor... | 01/01/70 00:00 | |
pull up on ds1307 sqwout | 01/01/70 00:00 | |
| Pullup resistor size... | 01/01/70 00:00 | |
| clock halt bit? | 01/01/70 00:00 | |
| ds1307 and i2c problem | 01/01/70 00:00 | |
| A 10MHz analog scope is fine for 100kHz i2c | 01/01/70 00:00 |