Emmanuel Blot
Emmanuel Blot
FTDI does not provide any documentation about how their chips behave, so it is hard to tell. 40 MB/s is the peak transfer rate on a USB2 HS bus. It...
To perform an I2C read out, it takes many MPSSE commands (that is the commands of the FTDI protocol). When I say many, that's a lot of them: to read...
Ok, a quick and dirty hack shows that it is possible to improve quite a lot I2C read transfers. It is too early to even release a patch, but I'll...
Can you give a try to the (i2c_streaming)[https://github.com/eblot/pyftdi/tree/i2c_streaming] branch? It is a quick experiment to optimise I2C transfer bandwidth and most importantly reduce I2C bus stalls. Using an I2C EEPROM...
Does it improve the reliability with your sensor ?
Ok, too bad, sorry about that. Could you post a Saleae capture of what libmpsse achieves? I do not think it is possible to be as efficient with Python, but...
Definitely, a C implementation do go much faster than a Python one. SWIG is some kind of legacy way to access native code, but it is does not change the...
Thanks. If you come across any useful info, please let me know. I keep this ticket open till I can deliver this updated version with shorter stalls.
I think I can tell you why :-) To make I2C working, FTDI needs to enable what they call a "3 phase clock". PyFtdi implements this feature. The issue with...
I do not think it changes anything: * pyftdi changes the submitted frequency so that it is 3:2 the one provided when I2C mode is activated * libmpsse expects the...