Hi all,
I have connected the TX pin on the BMV 700 directly to the RX GPIO on my raspberry 3.
I considered it safe because the VE.Direct interface on BMV-700 should be 3.3 V
I was expecting readable text, but this is what I got:
The input stops when I disconnect the wire from the battery monitor, so I'm sure the signal is coming from the battery monitor.
Just in case, I also connected the ground pin from the battery monitor to the raspberry, but couldn't see any changes.
After some digging, I found the following pattern repeating over and over with some small variations:
42 d2 4a df 83 c5 55 31 03 ab ff
42 d2 11 02 53 5d 85 9a 12 4b 31 03 a7 89 ff
42 d2 b5 ac c1 84 51 4d
42 d2 2d e5
42 d2 b6 b4 8a d7 73 03 b7 89 3b 03 a7 b4 b8 42 4d 99 da 22 69 e9 83 02 7f 0a 1a 57 89 5e 6542 d2 ca cb 55 46 4b 10 8a 92 6b 4e 80 fd 42 e2 0d 00 c5 05 d7 42 ea 89 53 6d 84 9a 4d d1 0a98 a2 69 e 32c e4 42 ee 4b 89 51 83 42 e2 71 80 22 69 63 43 9d 80 5b 99 92 b3 0a 98 5a 59 9e 10 0d a2 69 e1 7b a9 51 73 c3 ef 89 53 c3 42 ce 36 92 6b 4e 80 ff
42 d2 4a df 83 c5 55 31 03 ab 89 ff
42 d2 11 02 53 5d 85 9a 12 4b 31 03 a7 89 ff
42 d2 b5 ac c1 84 51 4d
42 d2 2d e5
42 d2 b6 b4 8a d7 73 03 b7 89 3b 03 a7 b4 b8 42 4d 99 da 22 69 e9 83 02 7f 0a 1a 57 89 5e 65 42 d2 ca cb 55 46 4b 10 8a 92 6b 4e 99 42 e2 0d 00 c5 05 d7 42 ea 89 53 6d 84 9a 4d d1 0a 98 a2 69 e3 2c e4 42 ee 4b 89 51 83 42 e2 71 80 22 69 63 43 bd 80 5b 99 92 b3 0a 98 5a 59 9e 10 0d a2 69 e1 7b a9 51 73 c3 ef 89 53 c3 42 ce 36 92 6b 4e 80 ff
The next "block" also has some small variations to the first ones. I made a line change on each "42 d2". I can see 6 of these, which matches the number of labels in bmv 700 according to https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjFj5j5y7DvAhWxPOwKHYzhBdsQFjABegQIAhAD&url=https%3A%2F%2Fforum.arduino.cc%2Findex.php%3Faction%3Ddlattach%3Btopic%3D668006.0%3Battach%3D348859&usg=AOvVaw2FUFsorSfRHD3stzo48Clj.
Is the signal somehow distorted because I have connected the battery monitor directly to the raspberry or is there anything else I haven't thought about?