Read the power of the smart meter with M5StickC (BP35C0-J11-T01)
Overview
Hack a home smart meter with M5StickC! was tried with BP35C0-J11-T01.
About BP35C0-J11-T01
BP35C0-J11-T01 is a wireless module BP35C0-J11 compatible with ROHM's B route / Enhanced HAN that can be inserted into a 2.54 mm pitch board. (Is BP35C1-J11-T01 in the series the same connector as BP35A1?) The features of BP35C0-J11 compared with BP35A1 which is often used in articles on the Internet are as follows.
--Supports Wi-SUN Enhanced HAN communication -** Command transmission / reception is J11-UART standard binary ** (BP35A1 is SK command for SKSTACK-IP, text-based)
Since the command system changed, it was necessary to rewrite most of it, so I made it public.
What you have prepared
- BP35C0-J11-T01 --External antenna
- M5StickC
- bread board
The BP35C0-J11 requires an external antenna, but since it is a specific low-power radio, it is necessary to use one that has been confirmed to be technically compatible with the BP35C0-J11. (A list of compatible products can be found here)
Wiring
Connect M5Stick C and BP35C0-J11-T01 as follows. If you try to insert it directly into the breadboard, CN3 will get in the way, so you need to remove the pin header of CN3 or geta geta with a pin socket.
| M5StickC | BP35C0-J11-T01 |
|---|---|
| GND | CN1-1 or 9(GND) |
| 3V3 | CN1-4 or 5(VCC) |
| G36 | CN2-5(TXD) |
| G26 | CN2-7(RESET) |
| G0 | CN2-4(RXD) |
program
Upload test_WiSUN_Ambient_J11.py instead of test_WiSUN_Ambient.py in the steps in Original Program. Since the code related to ESPNOW is compatible, the monitor slave unit can use the original program as it is.
Points to consider
--Readline cannot be used because the response is a variable length binary --It is necessary to add a checksum when sending a command. --The content read by read does not always include one response sentence completely, and conversely, two or more sentences may have been received. ――If you run it for several days, PANA re-authentication communication may fail and you may not be able to communicate with the smart meter → Deal with automatic restart
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