Hi to everyone
I bought 3 7-segment LED displays with the ambition to drive them by RASPBERRY PI leveraging on etiher I2C interface or SERIAL (SV3).
All the temptative I did to change the I2C or SERIAL address of the displays failed.
In both cases I write into the EPROM ADDRESSES 1 (0x01), 14 (0x0e), 250 (0xfa) a new address (i.e 100) rather than the current one (98 for serial and 49 for I2C since it used the 7 bit address notation). The write operation was successful since I try to read the relevant addresses and they contained exactly the wanted values but after a soft reset ("C" command for serial and 0x95 for I2C) they go back to their initial values (98 or 49)
Few more infos on the temptatives i did:
- to change the address i connected the display once at time
- for serial interface I leveraged the python library SERIAL. I used write() and read() commands
- for I2C interface I leveraged on the I2Ctools. Commands used form I2C tools were : i2cdetect, i2cset, i2cget. eprom commands send by i2cset were 0x90 (read) 0x91 (write) 0x95 (reset)
- i feed them with 5v power supply (for the I2C on raspberry i use a level shifter to bring the SDA/SCL signal level up to 5v). With serial i did not use any level shifter but i tried also to swap the power supply to 3.3 v with no changes on results... (displays were just more dimmed)
- all remaining commands (i.e setting up a number or a byte or the brightness on a specific digit) were working fine whatever interface i used
- every other I2C device i had on my I2C bus works well (i have the pullup resistor there)
any help will be appreciated, thx