ianmorris1960
New Member
- Joined
- Nov 26, 2020
- Messages
- 27
yes, interestingly looking at the protocol document from LLT it says the uart in the bms is 5v, it certainly doesnt look that way to me! I will be digging in my box of bits and building a level shifter based on BSS138, and a 317 variable regulator to produce the 1.7v reference needed. then with the level shifted to 3v3 see if it works then. it turns out 1v7 is in the grey area for the esp2866 chip - neither 1 or 0 so little wonder it didnt work, the ftdi must be more tolerant. I looked at the BLE module, there is a voltage regulator on there... 12v-> whatever, and then a chip with its' legend removed. it to must be tolerant.Thanks Ian for looking into that. I wonder if my 14s bmss have this issue. They all work fine with the bluetooth dongle, but no luck yet with the ESP01/ESP2866 wifi dongles. Two other 10s bmss are working good over wifi. I have a scope but not so familiar with it, so I should give that a shot.
Next step, level shifter on the tx from bms to bump it up to 3.3v?
Will report back when I have more news